includes/Title.php

   1 <?php
   2 /**
   3  * Representation a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  *
  31  * @internal documentation reviewed 15 Mar 2010
  32  */
  33 class Title {
  34         /** @name Static cache variables */
  35         // @{
  36         static private $titleCache = array();
  37         // @}
  38
  39         /**
  40          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  41          * commonly used titles. On a batch operation this can become a memory leak
  42          * if not bounded. After hitting this many titles reset the cache.
  43          */
  44         const CACHE_MAX = 1000;
  45
  46         /**
  47          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  48          * to use the master DB
  49          */
  50         const GAID_FOR_UPDATE = 1;
  51
  52         /**
  53          * @name Private member variables
  54          * Please use the accessor functions instead.
  55          * @private
  56          */
  57         // @{
  58
  59         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  60         var $mUrlform = '';               // /< URL-encoded form of the main part
  61         var $mDbkeyform = '';             // /< Main part with underscores
  62         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  63         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  64         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  65         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  66         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  67         var $mLatestID = false;           // /< ID of most recent revision
  68         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  69         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  70         var $mOldRestrictions = false;
  71         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  72         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  73         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  74         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  75         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  76         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  77         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  78         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  79         # Don't change the following default, NS_MAIN is hardcoded in several
  80         # places.  See bug 696.
  81         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  82                                                                           # Zero except in {{transclusion}} tags
  83         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  84         var $mLength = -1;                // /< The page length, 0 for special pages
  85         var $mRedirect = null;            // /< Is the article at this title a redirect?
  86         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  87         var $mHasSubpage;                 // /< Whether a page has any subpages
  88         // @}
  89
  90
  91         /**
  92          * Constructor
  93          */
  94         /*protected*/ function __construct() { }
  95
  96         /**
  97          * Create a new Title from a prefixed DB key
  98          *
  99          * @param $key String the database key, which has underscores
 100          *      instead of spaces, possibly including namespace and
 101          *      interwiki prefixes
 102          * @return Title, or NULL on an error
 103          */
 104         public static function newFromDBkey( $key ) {
 105                 $t = new Title();
 106                 $t->mDbkeyform = $key;
 107                 if ( $t->secureAndSplit() ) {
 108                         return $t;
 109                 } else {
 110                         return null;
 111                 }
 112         }
 113
 114         /**
 115          * Create a new Title from text, such as what one would find in a link. De-
 116          * codes any HTML entities in the text.
 117          *
 118          * @param $text String the link text; spaces, prefixes, and an
 119          *   initial ':' indicating the main namespace are accepted.
 120          * @param $defaultNamespace Int the namespace to use if none is speci-
 121          *   fied by a prefix.  If you want to force a specific namespace even if
 122          *   $text might begin with a namespace prefix, use makeTitle() or
 123          *   makeTitleSafe().
 124          * @throws MWException
 125          * @return Title|null - Title or null on an error.
 126          */
 127         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 128                 if ( is_object( $text ) ) {
 129                         throw new MWException( 'Title::newFromText given an object' );
 130                 }
 131
 132                 /**
 133                  * Wiki pages often contain multiple links to the same page.
 134                  * Title normalization and parsing can become expensive on
 135                  * pages with many links, so we can save a little time by
 136                  * caching them.
 137                  *
 138                  * In theory these are value objects and won't get changed...
 139                  */
 140                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 141                         return Title::$titleCache[$text];
 142                 }
 143
 144                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 145                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 146
 147                 $t = new Title();
 148                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 149                 $t->mDefaultNamespace = $defaultNamespace;
 150
 151                 static $cachedcount = 0 ;
 152                 if ( $t->secureAndSplit() ) {
 153                         if ( $defaultNamespace == NS_MAIN ) {
 154                                 if ( $cachedcount >= self::CACHE_MAX ) {
 155                                         # Avoid memory leaks on mass operations...
 156                                         Title::$titleCache = array();
 157                                         $cachedcount = 0;
 158                                 }
 159                                 $cachedcount++;
 160                                 Title::$titleCache[$text] =& $t;
 161                         }
 162                         return $t;
 163                 } else {
 164                         $ret = null;
 165                         return $ret;
 166                 }
 167         }
 168
 169         /**
 170          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 171          *
 172          * Example of wrong and broken code:
 173          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Example of right code:
 176          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 177          *
 178          * Create a new Title from URL-encoded text. Ensures that
 179          * the given title's length does not exceed the maximum.
 180          *
 181          * @param $url String the title, as might be taken from a URL
 182          * @return Title the new object, or NULL on an error
 183          */
 184         public static function newFromURL( $url ) {
 185                 $t = new Title();
 186
 187                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 188                 # but some URLs used it as a space replacement and they still come
 189                 # from some external search tools.
 190                 if ( strpos( self::legalChars(), '+' ) === false ) {
 191                         $url = str_replace( '+', ' ', $url );
 192                 }
 193
 194                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 195                 if ( $t->secureAndSplit() ) {
 196                         return $t;
 197                 } else {
 198                         return null;
 199                 }
 200         }
 201
 202         /**
 203          * Create a new Title from an article ID
 204          *
 205          * @param $id Int the page_id corresponding to the Title to create
 206          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 207          * @return Title the new object, or NULL on an error
 208          */
 209         public static function newFromID( $id, $flags = 0 ) {
 210                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 211                 $row = $db->selectRow(
 212                         'page',
 213                         array(
 214                                 'page_namespace', 'page_title', 'page_id',
 215                                 'page_len', 'page_is_redirect', 'page_latest',
 216                         ),
 217                         array( 'page_id' => $id ),
 218                         __METHOD__
 219                 );
 220                 if ( $row !== false ) {
 221                         $title = Title::newFromRow( $row );
 222                 } else {
 223                         $title = null;
 224                 }
 225                 return $title;
 226         }
 227
 228         /**
 229          * Make an array of titles from an array of IDs
 230          *
 231          * @param $ids Array of Int Array of IDs
 232          * @return Array of Titles
 233          */
 234         public static function newFromIDs( $ids ) {
 235                 if ( !count( $ids ) ) {
 236                         return array();
 237                 }
 238                 $dbr = wfGetDB( DB_SLAVE );
 239
 240                 $res = $dbr->select(
 241                         'page',
 242                         array(
 243                                 'page_namespace', 'page_title', 'page_id',
 244                                 'page_len', 'page_is_redirect', 'page_latest',
 245                         ),
 246                         array( 'page_id' => $ids ),
 247                         __METHOD__
 248                 );
 249
 250                 $titles = array();
 251                 foreach ( $res as $row ) {
 252                         $titles[] = Title::newFromRow( $row );
 253                 }
 254                 return $titles;
 255         }
 256
 257         /**
 258          * Make a Title object from a DB row
 259          *
 260          * @param $row Object database row (needs at least page_title,page_namespace)
 261          * @return Title corresponding Title
 262          */
 263         public static function newFromRow( $row ) {
 264                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 265                 $t->loadFromRow( $row );
 266                 return $t;
 267         }
 268
 269         /**
 270          * Load Title object fields from a DB row.
 271          * If false is given, the title will be treated as non-existing.
 272          *
 273          * @param $row Object|bool database row
 274          */
 275         public function loadFromRow( $row ) {
 276                 if ( $row ) { // page found
 277                         if ( isset( $row->page_id ) )
 278                                 $this->mArticleID = (int)$row->page_id;
 279                         if ( isset( $row->page_len ) )
 280                                 $this->mLength = (int)$row->page_len;
 281                         if ( isset( $row->page_is_redirect ) )
 282                                 $this->mRedirect = (bool)$row->page_is_redirect;
 283                         if ( isset( $row->page_latest ) )
 284                                 $this->mLatestID = (int)$row->page_latest;
 285                 } else { // page not found
 286                         $this->mArticleID = 0;
 287                         $this->mLength = 0;
 288                         $this->mRedirect = false;
 289                         $this->mLatestID = 0;
 290                 }
 291         }
 292
 293         /**
 294          * Create a new Title from a namespace index and a DB key.
 295          * It's assumed that $ns and $title are *valid*, for instance when
 296          * they came directly from the database or a special page name.
 297          * For convenience, spaces are converted to underscores so that
 298          * eg user_text fields can be used directly.
 299          *
 300          * @param $ns Int the namespace of the article
 301          * @param $title String the unprefixed database key form
 302          * @param $fragment String the link fragment (after the "#")
 303          * @param $interwiki String the interwiki prefix
 304          * @return Title the new object
 305          */
 306         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 307                 $t = new Title();
 308                 $t->mInterwiki = $interwiki;
 309                 $t->mFragment = $fragment;
 310                 $t->mNamespace = $ns = intval( $ns );
 311                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 312                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 313                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 314                 $t->mTextform = str_replace( '_', ' ', $title );
 315                 return $t;
 316         }
 317
 318         /**
 319          * Create a new Title from a namespace index and a DB key.
 320          * The parameters will be checked for validity, which is a bit slower
 321          * than makeTitle() but safer for user-provided data.
 322          *
 323          * @param $ns Int the namespace of the article
 324          * @param $title String database key form
 325          * @param $fragment String the link fragment (after the "#")
 326          * @param $interwiki String interwiki prefix
 327          * @return Title the new object, or NULL on an error
 328          */
 329         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 330                 if ( !MWNamespace::exists( $ns ) ) {
 331                         return null;
 332                 }
 333
 334                 $t = new Title();
 335                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 336                 if ( $t->secureAndSplit() ) {
 337                         return $t;
 338                 } else {
 339                         return null;
 340                 }
 341         }
 342
 343         /**
 344          * Create a new Title for the Main Page
 345          *
 346          * @return Title the new object
 347          */
 348         public static function newMainPage() {
 349                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 350                 // Don't give fatal errors if the message is broken
 351                 if ( !$title ) {
 352                         $title = Title::newFromText( 'Main Page' );
 353                 }
 354                 return $title;
 355         }
 356
 357         /**
 358          * Extract a redirect destination from a string and return the
 359          * Title, or null if the text doesn't contain a valid redirect
 360          * This will only return the very next target, useful for
 361          * the redirect table and other checks that don't need full recursion
 362          *
 363          * @param $text String: Text with possible redirect
 364          * @return Title: The corresponding Title
 365          */
 366         public static function newFromRedirect( $text ) {
 367                 return self::newFromRedirectInternal( $text );
 368         }
 369
 370         /**
 371          * Extract a redirect destination from a string and return the
 372          * Title, or null if the text doesn't contain a valid redirect
 373          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 374          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 375          *
 376          * @param $text String Text with possible redirect
 377          * @return Title
 378          */
 379         public static function newFromRedirectRecurse( $text ) {
 380                 $titles = self::newFromRedirectArray( $text );
 381                 return $titles ? array_pop( $titles ) : null;
 382         }
 383
 384         /**
 385          * Extract a redirect destination from a string and return an
 386          * array of Titles, or null if the text doesn't contain a valid redirect
 387          * The last element in the array is the final destination after all redirects
 388          * have been resolved (up to $wgMaxRedirects times)
 389          *
 390          * @param $text String Text with possible redirect
 391          * @return Array of Titles, with the destination last
 392          */
 393         public static function newFromRedirectArray( $text ) {
 394                 global $wgMaxRedirects;
 395                 $title = self::newFromRedirectInternal( $text );
 396                 if ( is_null( $title ) ) {
 397                         return null;
 398                 }
 399                 // recursive check to follow double redirects
 400                 $recurse = $wgMaxRedirects;
 401                 $titles = array( $title );
 402                 while ( --$recurse > 0 ) {
 403                         if ( $title->isRedirect() ) {
 404                                 $page = WikiPage::factory( $title );
 405                                 $newtitle = $page->getRedirectTarget();
 406                         } else {
 407                                 break;
 408                         }
 409                         // Redirects to some special pages are not permitted
 410                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 411                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 412                                 $title = $newtitle;
 413                                 $titles[] = $newtitle;
 414                         } else {
 415                                 break;
 416                         }
 417                 }
 418                 return $titles;
 419         }
 420
 421         /**
 422          * Really extract the redirect destination
 423          * Do not call this function directly, use one of the newFromRedirect* functions above
 424          *
 425          * @param $text String Text with possible redirect
 426          * @return Title
 427          */
 428         protected static function newFromRedirectInternal( $text ) {
 429                 global $wgMaxRedirects;
 430                 if ( $wgMaxRedirects < 1 ) {
 431                         //redirects are disabled, so quit early
 432                         return null;
 433                 }
 434                 $redir = MagicWord::get( 'redirect' );
 435                 $text = trim( $text );
 436                 if ( $redir->matchStartAndRemove( $text ) ) {
 437                         // Extract the first link and see if it's usable
 438                         // Ensure that it really does come directly after #REDIRECT
 439                         // Some older redirects included a colon, so don't freak about that!
 440                         $m = array();
 441                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 442                                 // Strip preceding colon used to "escape" categories, etc.
 443                                 // and URL-decode links
 444                                 if ( strpos( $m[1], '%' ) !== false ) {
 445                                         // Match behavior of inline link parsing here;
 446                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 447                                 }
 448                                 $title = Title::newFromText( $m[1] );
 449                                 // If the title is a redirect to bad special pages or is invalid, return null
 450                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 451                                         return null;
 452                                 }
 453                                 return $title;
 454                         }
 455                 }
 456                 return null;
 457         }
 458
 459         /**
 460          * Get the prefixed DB key associated with an ID
 461          *
 462          * @param $id Int the page_id of the article
 463          * @return Title an object representing the article, or NULL if no such article was found
 464          */
 465         public static function nameOf( $id ) {
 466                 $dbr = wfGetDB( DB_SLAVE );
 467
 468                 $s = $dbr->selectRow(
 469                         'page',
 470                         array( 'page_namespace', 'page_title' ),
 471                         array( 'page_id' => $id ),
 472                         __METHOD__
 473                 );
 474                 if ( $s === false ) {
 475                         return null;
 476                 }
 477
 478                 $n = self::makeName( $s->page_namespace, $s->page_title );
 479                 return $n;
 480         }
 481
 482         /**
 483          * Get a regex character class describing the legal characters in a link
 484          *
 485          * @return String the list of characters, not delimited
 486          */
 487         public static function legalChars() {
 488                 global $wgLegalTitleChars;
 489                 return $wgLegalTitleChars;
 490         }
 491
 492         /**
 493          * Returns a simple regex that will match on characters and sequences invalid in titles.
 494          * Note that this doesn't pick up many things that could be wrong with titles, but that
 495          * replacing this regex with something valid will make many titles valid.
 496          *
 497          * @return String regex string
 498          */
 499         static function getTitleInvalidRegex() {
 500                 static $rxTc = false;
 501                 if ( !$rxTc ) {
 502                         # Matching titles will be held as illegal.
 503                         $rxTc = '/' .
 504                                 # Any character not allowed is forbidden...
 505                                 '[^' . self::legalChars() . ']' .
 506                                 # URL percent encoding sequences interfere with the ability
 507                                 # to round-trip titles -- you can't link to them consistently.
 508                                 '|%[0-9A-Fa-f]{2}' .
 509                                 # XML/HTML character references produce similar issues.
 510                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 511                                 '|&#[0-9]+;' .
 512                                 '|&#x[0-9A-Fa-f]+;' .
 513                                 '/S';
 514                 }
 515
 516                 return $rxTc;
 517         }
 518
 519         /**
 520          * Get a string representation of a title suitable for
 521          * including in a search index
 522          *
 523          * @param $ns Int a namespace index
 524          * @param $title String text-form main part
 525          * @return String a stripped-down title string ready for the search index
 526          */
 527         public static function indexTitle( $ns, $title ) {
 528                 global $wgContLang;
 529
 530                 $lc = SearchEngine::legalSearchChars() . '&#;';
 531                 $t = $wgContLang->normalizeForSearch( $title );
 532                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 533                 $t = $wgContLang->lc( $t );
 534
 535                 # Handle 's, s'
 536                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 537                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 538
 539                 $t = preg_replace( "/\\s+/", ' ', $t );
 540
 541                 if ( $ns == NS_FILE ) {
 542                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 543                 }
 544                 return trim( $t );
 545         }
 546
 547         /**
 548          * Make a prefixed DB key from a DB key and a namespace index
 549          *
 550          * @param $ns Int numerical representation of the namespace
 551          * @param $title String the DB key form the title
 552          * @param $fragment String The link fragment (after the "#")
 553          * @param $interwiki String The interwiki prefix
 554          * @return String the prefixed form of the title
 555          */
 556         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 557                 global $wgContLang;
 558
 559                 $namespace = $wgContLang->getNsText( $ns );
 560                 $name = $namespace == '' ? $title : "$namespace:$title";
 561                 if ( strval( $interwiki ) != '' ) {
 562                         $name = "$interwiki:$name";
 563                 }
 564                 if ( strval( $fragment ) != '' ) {
 565                         $name .= '#' . $fragment;
 566                 }
 567                 return $name;
 568         }
 569
 570         /**
 571          * Escape a text fragment, say from a link, for a URL
 572          *
 573          * @param $fragment string containing a URL or link fragment (after the "#")
 574          * @return String: escaped string
 575          */
 576         static function escapeFragmentForURL( $fragment ) {
 577                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 578                 # fragments appear not to work in IE (at least up to 7) or in at least
 579                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 580                 # to care if they aren't encoded.
 581                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 582         }
 583
 584         /**
 585          * Callback for usort() to do title sorts by (namespace, title)
 586          *
 587          * @param $a Title
 588          * @param $b Title
 589          *
 590          * @return Integer: result of string comparison, or namespace comparison
 591          */
 592         public static function compare( $a, $b ) {
 593                 if ( $a->getNamespace() == $b->getNamespace() ) {
 594                         return strcmp( $a->getText(), $b->getText() );
 595                 } else {
 596                         return $a->getNamespace() - $b->getNamespace();
 597                 }
 598         }
 599
 600         /**
 601          * Determine whether the object refers to a page within
 602          * this project.
 603          *
 604          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 605          */
 606         public function isLocal() {
 607                 if ( $this->mInterwiki != '' ) {
 608                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 609                 } else {
 610                         return true;
 611                 }
 612         }
 613
 614         /**
 615          * Is this Title interwiki?
 616          *
 617          * @return Bool
 618          */
 619         public function isExternal() {
 620                 return ( $this->mInterwiki != '' );
 621         }
 622
 623         /**
 624          * Get the interwiki prefix (or null string)
 625          *
 626          * @return String Interwiki prefix
 627          */
 628         public function getInterwiki() {
 629                 return $this->mInterwiki;
 630         }
 631
 632         /**
 633          * Determine whether the object refers to a page within
 634          * this project and is transcludable.
 635          *
 636          * @return Bool TRUE if this is transcludable
 637          */
 638         public function isTrans() {
 639                 if ( $this->mInterwiki == '' ) {
 640                         return false;
 641                 }
 642
 643                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 644         }
 645
 646         /**
 647          * Returns the DB name of the distant wiki which owns the object.
 648          *
 649          * @return String the DB name
 650          */
 651         public function getTransWikiID() {
 652                 if ( $this->mInterwiki == '' ) {
 653                         return false;
 654                 }
 655
 656                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 657         }
 658
 659         /**
 660          * Get the text form (spaces not underscores) of the main part
 661          *
 662          * @return String Main part of the title
 663          */
 664         public function getText() {
 665                 return $this->mTextform;
 666         }
 667
 668         /**
 669          * Get the URL-encoded form of the main part
 670          *
 671          * @return String Main part of the title, URL-encoded
 672          */
 673         public function getPartialURL() {
 674                 return $this->mUrlform;
 675         }
 676
 677         /**
 678          * Get the main part with underscores
 679          *
 680          * @return String: Main part of the title, with underscores
 681          */
 682         public function getDBkey() {
 683                 return $this->mDbkeyform;
 684         }
 685
 686         /**
 687          * Get the DB key with the initial letter case as specified by the user
 688          *
 689          * @return String DB key
 690          */
 691         function getUserCaseDBKey() {
 692                 return $this->mUserCaseDBKey;
 693         }
 694
 695         /**
 696          * Get the namespace index, i.e. one of the NS_xxxx constants.
 697          *
 698          * @return Integer: Namespace index
 699          */
 700         public function getNamespace() {
 701                 return $this->mNamespace;
 702         }
 703
 704         /**
 705          * Get the namespace text
 706          *
 707          * @return String: Namespace text
 708          */
 709         public function getNsText() {
 710                 global $wgContLang;
 711
 712                 if ( $this->mInterwiki != '' ) {
 713                         // This probably shouldn't even happen. ohh man, oh yuck.
 714                         // But for interwiki transclusion it sometimes does.
 715                         // Shit. Shit shit shit.
 716                         //
 717                         // Use the canonical namespaces if possible to try to
 718                         // resolve a foreign namespace.
 719                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 720                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 721                         }
 722                 }
 723
 724                 if ( $wgContLang->needsGenderDistinction() &&
 725                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 726                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 727                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 728                 }
 729
 730                 return $wgContLang->getNsText( $this->mNamespace );
 731         }
 732
 733         /**
 734          * Get the namespace text of the subject (rather than talk) page
 735          *
 736          * @return String Namespace text
 737          */
 738         public function getSubjectNsText() {
 739                 global $wgContLang;
 740                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 741         }
 742
 743         /**
 744          * Get the namespace text of the talk page
 745          *
 746          * @return String Namespace text
 747          */
 748         public function getTalkNsText() {
 749                 global $wgContLang;
 750                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 751         }
 752
 753         /**
 754          * Could this title have a corresponding talk page?
 755          *
 756          * @return Bool TRUE or FALSE
 757          */
 758         public function canTalk() {
 759                 return( MWNamespace::canTalk( $this->mNamespace ) );
 760         }
 761
 762         /**
 763          * Is this in a namespace that allows actual pages?
 764          *
 765          * @return Bool
 766          * @internal note -- uses hardcoded namespace index instead of constants
 767          */
 768         public function canExist() {
 769                 return $this->mNamespace >= NS_MAIN;
 770         }
 771
 772         /**
 773          * Can this title be added to a user's watchlist?
 774          *
 775          * @return Bool TRUE or FALSE
 776          */
 777         public function isWatchable() {
 778                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 779         }
 780
 781         /**
 782          * Returns true if this is a special page.
 783          *
 784          * @return boolean
 785          */
 786         public function isSpecialPage() {
 787                 return $this->getNamespace() == NS_SPECIAL;
 788         }
 789
 790         /**
 791          * Returns true if this title resolves to the named special page
 792          *
 793          * @param $name String The special page name
 794          * @return boolean
 795          */
 796         public function isSpecial( $name ) {
 797                 if ( $this->isSpecialPage() ) {
 798                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 799                         if ( $name == $thisName ) {
 800                                 return true;
 801                         }
 802                 }
 803                 return false;
 804         }
 805
 806         /**
 807          * If the Title refers to a special page alias which is not the local default, resolve
 808          * the alias, and localise the name as necessary.  Otherwise, return $this
 809          *
 810          * @return Title
 811          */
 812         public function fixSpecialName() {
 813                 if ( $this->isSpecialPage() ) {
 814                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 815                         if ( $canonicalName ) {
 816                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 817                                 if ( $localName != $this->mDbkeyform ) {
 818                                         return Title::makeTitle( NS_SPECIAL, $localName );
 819                                 }
 820                         }
 821                 }
 822                 return $this;
 823         }
 824
 825         /**
 826          * Returns true if the title is inside the specified namespace.
 827          *
 828          * Please make use of this instead of comparing to getNamespace()
 829          * This function is much more resistant to changes we may make
 830          * to namespaces than code that makes direct comparisons.
 831          * @param $ns int The namespace
 832          * @return bool
 833          * @since 1.19
 834          */
 835         public function inNamespace( $ns ) {
 836                 return MWNamespace::equals( $this->getNamespace(), $ns );
 837         }
 838
 839         /**
 840          * Returns true if the title is inside one of the specified namespaces.
 841          *
 842          * @param ...$namespaces The namespaces to check for
 843          * @return bool
 844          * @since 1.19
 845          */
 846         public function inNamespaces( /* ... */ ) {
 847                 $namespaces = func_get_args();
 848                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 849                         $namespaces = $namespaces[0];
 850                 }
 851
 852                 foreach ( $namespaces as $ns ) {
 853                         if ( $this->inNamespace( $ns ) ) {
 854                                 return true;
 855                         }
 856                 }
 857
 858                 return false;
 859         }
 860
 861         /**
 862          * Returns true if the title has the same subject namespace as the
 863          * namespace specified.
 864          * For example this method will take NS_USER and return true if namespace
 865          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 866          * as their subject namespace.
 867          *
 868          * This is MUCH simpler than individually testing for equivilance
 869          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 870          * @since 1.19
 871          * @param $ns int
 872          * @return bool
 873          */
 874         public function hasSubjectNamespace( $ns ) {
 875                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 876         }
 877
 878         /**
 879          * Is this Title in a namespace which contains content?
 880          * In other words, is this a content page, for the purposes of calculating
 881          * statistics, etc?
 882          *
 883          * @return Boolean
 884          */
 885         public function isContentPage() {
 886                 return MWNamespace::isContent( $this->getNamespace() );
 887         }
 888
 889         /**
 890          * Would anybody with sufficient privileges be able to move this page?
 891          * Some pages just aren't movable.
 892          *
 893          * @return Bool TRUE or FALSE
 894          */
 895         public function isMovable() {
 896                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 897                         // Interwiki title or immovable namespace. Hooks don't get to override here
 898                         return false;
 899                 }
 900
 901                 $result = true;
 902                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 903                 return $result;
 904         }
 905
 906         /**
 907          * Is this the mainpage?
 908          * @note Title::newFromText seams to be sufficiently optimized by the title
 909          * cache that we don't need to over-optimize by doing direct comparisons and
 910          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 911          * ends up reporting something differently than $title->isMainPage();
 912          *
 913          * @since 1.18
 914          * @return Bool
 915          */
 916         public function isMainPage() {
 917                 return $this->equals( Title::newMainPage() );
 918         }
 919
 920         /**
 921          * Is this a subpage?
 922          *
 923          * @return Bool
 924          */
 925         public function isSubpage() {
 926                 return MWNamespace::hasSubpages( $this->mNamespace )
 927                         ? strpos( $this->getText(), '/' ) !== false
 928                         : false;
 929         }
 930
 931         /**
 932          * Is this a conversion table for the LanguageConverter?
 933          *
 934          * @return Bool
 935          */
 936         public function isConversionTable() {
 937                 return $this->getNamespace() == NS_MEDIAWIKI &&
 938                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
 939         }
 940
 941         /**
 942          * Does that page contain wikitext, or it is JS, CSS or whatever?
 943          *
 944          * @return Bool
 945          */
 946         public function isWikitextPage() {
 947                 $retval = !$this->isCssOrJsPage() && !$this->isCssJsSubpage();
 948                 wfRunHooks( 'TitleIsWikitextPage', array( $this, &$retval ) );
 949                 return $retval;
 950         }
 951
 952         /**
 953          * Could this page contain custom CSS or JavaScript, based
 954          * on the title?
 955          *
 956          * @return Bool
 957          */
 958         public function isCssOrJsPage() {
 959                 $retval = $this->mNamespace == NS_MEDIAWIKI
 960                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
 961                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$retval ) );
 962                 return $retval;
 963         }
 964
 965         /**
 966          * Is this a .css or .js subpage of a user page?
 967          * @return Bool
 968          */
 969         public function isCssJsSubpage() {
 970                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
 971         }
 972
 973         /**
 974          * Trim down a .css or .js subpage title to get the corresponding skin name
 975          *
 976          * @return string containing skin name from .css or .js subpage title
 977          */
 978         public function getSkinFromCssJsSubpage() {
 979                 $subpage = explode( '/', $this->mTextform );
 980                 $subpage = $subpage[ count( $subpage ) - 1 ];
 981                 $lastdot = strrpos( $subpage, '.' );
 982                 if ( $lastdot === false )
 983                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
 984                 return substr( $subpage, 0, $lastdot );
 985         }
 986
 987         /**
 988          * Is this a .css subpage of a user page?
 989          *
 990          * @return Bool
 991          */
 992         public function isCssSubpage() {
 993                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
 994         }
 995
 996         /**
 997          * Is this a .js subpage of a user page?
 998          *
 999          * @return Bool
1000          */
1001         public function isJsSubpage() {
1002                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1003         }
1004
1005         /**
1006          * Is this a talk page of some sort?
1007          *
1008          * @return Bool
1009          */
1010         public function isTalkPage() {
1011                 return MWNamespace::isTalk( $this->getNamespace() );
1012         }
1013
1014         /**
1015          * Get a Title object associated with the talk page of this article
1016          *
1017          * @return Title the object for the talk page
1018          */
1019         public function getTalkPage() {
1020                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1021         }
1022
1023         /**
1024          * Get a title object associated with the subject page of this
1025          * talk page
1026          *
1027          * @return Title the object for the subject page
1028          */
1029         public function getSubjectPage() {
1030                 // Is this the same title?
1031                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1032                 if ( $this->getNamespace() == $subjectNS ) {
1033                         return $this;
1034                 }
1035                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1036         }
1037
1038         /**
1039          * Get the default namespace index, for when there is no namespace
1040          *
1041          * @return Int Default namespace index
1042          */
1043         public function getDefaultNamespace() {
1044                 return $this->mDefaultNamespace;
1045         }
1046
1047         /**
1048          * Get title for search index
1049          *
1050          * @return String a stripped-down title string ready for the
1051          *  search index
1052          */
1053         public function getIndexTitle() {
1054                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1055         }
1056
1057         /**
1058          * Get the Title fragment (i.e.\ the bit after the #) in text form
1059          *
1060          * @return String Title fragment
1061          */
1062         public function getFragment() {
1063                 return $this->mFragment;
1064         }
1065
1066         /**
1067          * Get the fragment in URL form, including the "#" character if there is one
1068          * @return String Fragment in URL form
1069          */
1070         public function getFragmentForURL() {
1071                 if ( $this->mFragment == '' ) {
1072                         return '';
1073                 } else {
1074                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1075                 }
1076         }
1077
1078         /**
1079          * Set the fragment for this title. Removes the first character from the
1080          * specified fragment before setting, so it assumes you're passing it with
1081          * an initial "#".
1082          *
1083          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1084          * Still in active use privately.
1085          *
1086          * @param $fragment String text
1087          */
1088         public function setFragment( $fragment ) {
1089                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1090         }
1091
1092         /**
1093          * Prefix some arbitrary text with the namespace or interwiki prefix
1094          * of this object
1095          *
1096          * @param $name String the text
1097          * @return String the prefixed text
1098          * @private
1099          */
1100         private function prefix( $name ) {
1101                 $p = '';
1102                 if ( $this->mInterwiki != '' ) {
1103                         $p = $this->mInterwiki . ':';
1104                 }
1105
1106                 if ( 0 != $this->mNamespace ) {
1107                         $p .= $this->getNsText() . ':';
1108                 }
1109                 return $p . $name;
1110         }
1111
1112         /**
1113          * Get the prefixed database key form
1114          *
1115          * @return String the prefixed title, with underscores and
1116          *  any interwiki and namespace prefixes
1117          */
1118         public function getPrefixedDBkey() {
1119                 $s = $this->prefix( $this->mDbkeyform );
1120                 $s = str_replace( ' ', '_', $s );
1121                 return $s;
1122         }
1123
1124         /**
1125          * Get the prefixed title with spaces.
1126          * This is the form usually used for display
1127          *
1128          * @return String the prefixed title, with spaces
1129          */
1130         public function getPrefixedText() {
1131                 // @todo FIXME: Bad usage of empty() ?
1132                 if ( empty( $this->mPrefixedText ) ) {
1133                         $s = $this->prefix( $this->mTextform );
1134                         $s = str_replace( '_', ' ', $s );
1135                         $this->mPrefixedText = $s;
1136                 }
1137                 return $this->mPrefixedText;
1138         }
1139
1140         /**
1141          * Return a string representation of this title
1142          *
1143          * @return String representation of this title
1144          */
1145         public function __toString() {
1146                 return $this->getPrefixedText();
1147         }
1148
1149         /**
1150          * Get the prefixed title with spaces, plus any fragment
1151          * (part beginning with '#')
1152          *
1153          * @return String the prefixed title, with spaces and the fragment, including '#'
1154          */
1155         public function getFullText() {
1156                 $text = $this->getPrefixedText();
1157                 if ( $this->mFragment != '' ) {
1158                         $text .= '#' . $this->mFragment;
1159                 }
1160                 return $text;
1161         }
1162
1163         /**
1164          * Get the base page name, i.e. the leftmost part before any slashes
1165          *
1166          * @return String Base name
1167          */
1168         public function getBaseText() {
1169                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1170                         return $this->getText();
1171                 }
1172
1173                 $parts = explode( '/', $this->getText() );
1174                 # Don't discard the real title if there's no subpage involved
1175                 if ( count( $parts ) > 1 ) {
1176                         unset( $parts[count( $parts ) - 1] );
1177                 }
1178                 return implode( '/', $parts );
1179         }
1180
1181         /**
1182          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1183          *
1184          * @return String Subpage name
1185          */
1186         public function getSubpageText() {
1187                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1188                         return( $this->mTextform );
1189                 }
1190                 $parts = explode( '/', $this->mTextform );
1191                 return( $parts[count( $parts ) - 1] );
1192         }
1193
1194         /**
1195          * Get the HTML-escaped displayable text form.
1196          * Used for the title field in <a> tags.
1197          *
1198          * @return String the text, including any prefixes
1199          */
1200         public function getEscapedText() {
1201                 wfDeprecated( __METHOD__, '1.19' );
1202                 return htmlspecialchars( $this->getPrefixedText() );
1203         }
1204
1205         /**
1206          * Get a URL-encoded form of the subpage text
1207          *
1208          * @return String URL-encoded subpage name
1209          */
1210         public function getSubpageUrlForm() {
1211                 $text = $this->getSubpageText();
1212                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1213                 return( $text );
1214         }
1215
1216         /**
1217          * Get a URL-encoded title (not an actual URL) including interwiki
1218          *
1219          * @return String the URL-encoded form
1220          */
1221         public function getPrefixedURL() {
1222                 $s = $this->prefix( $this->mDbkeyform );
1223                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1224                 return $s;
1225         }
1226
1227         /**
1228          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1229          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1230          * second argument named variant. This was deprecated in favor
1231          * of passing an array of option with a "variant" key
1232          * Once $query2 is removed for good, this helper can be dropped
1233          * andthe wfArrayToCGI moved to getLocalURL();
1234          *
1235          * @since 1.19 (r105919)
1236          * @param $query
1237          * @param $query2 bool
1238          * @return String
1239          */
1240         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1241                 if( $query2 !== false ) {
1242                         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" );
1243                 }
1244                 if ( is_array( $query ) ) {
1245                         $query = wfArrayToCGI( $query );
1246                 }
1247                 if ( $query2 ) {
1248                         if ( is_string( $query2 ) ) {
1249                                 // $query2 is a string, we will consider this to be
1250                                 // a deprecated $variant argument and add it to the query
1251                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1252                         } else {
1253                                 $query2 = wfArrayToCGI( $query2 );
1254                         }
1255                         // If we have $query content add a & to it first
1256                         if ( $query ) {
1257                                 $query .= '&';
1258                         }
1259                         // Now append the queries together
1260                         $query .= $query2;
1261                 }
1262                 return $query;
1263         }
1264
1265         /**
1266          * Get a real URL referring to this title, with interwiki link and
1267          * fragment
1268          *
1269          * See getLocalURL for the arguments.
1270          *
1271          * @see self::getLocalURL
1272          * @see wfExpandUrl
1273          * @param $proto Protocol type to use in URL
1274          * @return String the URL
1275          */
1276         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1277                 $query = self::fixUrlQueryArgs( $query, $query2 );
1278
1279                 # Hand off all the decisions on urls to getLocalURL
1280                 $url = $this->getLocalURL( $query );
1281
1282                 # Expand the url to make it a full url. Note that getLocalURL has the
1283                 # potential to output full urls for a variety of reasons, so we use
1284                 # wfExpandUrl instead of simply prepending $wgServer
1285                 $url = wfExpandUrl( $url, $proto );
1286
1287                 # Finally, add the fragment.
1288                 $url .= $this->getFragmentForURL();
1289
1290                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1291                 return $url;
1292         }
1293
1294         /**
1295          * Get a URL with no fragment or server name.  If this page is generated
1296          * with action=render, $wgServer is prepended.
1297          *
1298
1299          * @param $query string|array an optional query string,
1300          *   not used for interwiki     links. Can be specified as an associative array as well,
1301          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1302          *   Some query patterns will trigger various shorturl path replacements.
1303          * @param $query2 Mixed: An optional secondary query array. This one MUST
1304          *   be an array. If a string is passed it will be interpreted as a deprecated
1305          *   variant argument and urlencoded into a variant= argument.
1306          *   This second query argument will be added to the $query
1307          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1308          *   pair in the first parameter array instead.
1309          *
1310          * @return String the URL
1311          */
1312         public function getLocalURL( $query = '', $query2 = false ) {
1313                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1314
1315                 $query = self::fixUrlQueryArgs( $query, $query2 );
1316
1317                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1318                 if ( $interwiki ) {
1319                         $namespace = $this->getNsText();
1320                         if ( $namespace != '' ) {
1321                                 # Can this actually happen? Interwikis shouldn't be parsed.
1322                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1323                                 $namespace .= ':';
1324                         }
1325                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1326                         $url = wfAppendQuery( $url, $query );
1327                 } else {
1328                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1329                         if ( $query == '' ) {
1330                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1331                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1332                         } else {
1333                                 global $wgVariantArticlePath, $wgActionPaths;
1334                                 $url = false;
1335                                 $matches = array();
1336
1337                                 if ( !empty( $wgActionPaths ) &&
1338                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1339                                 {
1340                                         $action = urldecode( $matches[2] );
1341                                         if ( isset( $wgActionPaths[$action] ) ) {
1342                                                 $query = $matches[1];
1343                                                 if ( isset( $matches[4] ) ) {
1344                                                         $query .= $matches[4];
1345                                                 }
1346                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1347                                                 if ( $query != '' ) {
1348                                                         $url = wfAppendQuery( $url, $query );
1349                                                 }
1350                                         }
1351                                 }
1352
1353                                 if ( $url === false &&
1354                                         $wgVariantArticlePath &&
1355                                         $this->getPageLanguage()->hasVariants() &&
1356                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1357                                 {
1358                                         $variant = urldecode( $matches[1] );
1359                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1360                                                 // Only do the variant replacement if the given variant is a valid
1361                                                 // variant for the page's language.
1362                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1363                                                 $url = str_replace( '$1', $dbkey, $url );
1364                                         }
1365                                 }
1366
1367                                 if ( $url === false ) {
1368                                         if ( $query == '-' ) {
1369                                                 $query = '';
1370                                         }
1371                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1372                                 }
1373                         }
1374
1375                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1376
1377                         // @todo FIXME: This causes breakage in various places when we
1378                         // actually expected a local URL and end up with dupe prefixes.
1379                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1380                                 $url = $wgServer . $url;
1381                         }
1382                 }
1383                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1384                 return $url;
1385         }
1386
1387         /**
1388          * Get a URL that's the simplest URL that will be valid to link, locally,
1389          * to the current Title.  It includes the fragment, but does not include
1390          * the server unless action=render is used (or the link is external).  If
1391          * there's a fragment but the prefixed text is empty, we just return a link
1392          * to the fragment.
1393          *
1394          * The result obviously should not be URL-escaped, but does need to be
1395          * HTML-escaped if it's being output in HTML.
1396          *
1397          * See getLocalURL for the arguments.
1398          *
1399          * @see self::getLocalURL
1400          * @return String the URL
1401          */
1402         public function getLinkURL( $query = '', $query2 = false ) {
1403                 wfProfileIn( __METHOD__ );
1404                 if ( $this->isExternal() ) {
1405                         $ret = $this->getFullURL( $query, $query2 );
1406                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1407                         $ret = $this->getFragmentForURL();
1408                 } else {
1409                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1410                 }
1411                 wfProfileOut( __METHOD__ );
1412                 return $ret;
1413         }
1414
1415         /**
1416          * Get an HTML-escaped version of the URL form, suitable for
1417          * using in a link, without a server name or fragment
1418          *
1419          * See getLocalURL for the arguments.
1420          *
1421          * @see self::getLocalURL
1422          * @param $query string
1423          * @param $query2 bool|string
1424          * @return String the URL
1425          */
1426         public function escapeLocalURL( $query = '', $query2 = false ) {
1427                 wfDeprecated( __METHOD__, '1.19' );
1428                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1429         }
1430
1431         /**
1432          * Get an HTML-escaped version of the URL form, suitable for
1433          * using in a link, including the server name and fragment
1434          *
1435          * See getLocalURL for the arguments.
1436          *
1437          * @see self::getLocalURL
1438          * @return String the URL
1439          */
1440         public function escapeFullURL( $query = '', $query2 = false ) {
1441                 wfDeprecated( __METHOD__, '1.19' );
1442                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1443         }
1444
1445         /**
1446          * Get the URL form for an internal link.
1447          * - Used in various Squid-related code, in case we have a different
1448          * internal hostname for the server from the exposed one.
1449          *
1450          * This uses $wgInternalServer to qualify the path, or $wgServer
1451          * if $wgInternalServer is not set. If the server variable used is
1452          * protocol-relative, the URL will be expanded to http://
1453          *
1454          * See getLocalURL for the arguments.
1455          *
1456          * @see self::getLocalURL
1457          * @return String the URL
1458          */
1459         public function getInternalURL( $query = '', $query2 = false ) {
1460                 global $wgInternalServer, $wgServer;
1461                 $query = self::fixUrlQueryArgs( $query, $query2 );
1462                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1463                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1464                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1465                 return $url;
1466         }
1467
1468         /**
1469          * Get the URL for a canonical link, for use in things like IRC and
1470          * e-mail notifications. Uses $wgCanonicalServer and the
1471          * GetCanonicalURL hook.
1472          *
1473          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1474          *
1475          * See getLocalURL for the arguments.
1476          *
1477          * @see self::getLocalURL
1478          * @return string The URL
1479          * @since 1.18
1480          */
1481         public function getCanonicalURL( $query = '', $query2 = false ) {
1482                 $query = self::fixUrlQueryArgs( $query, $query2 );
1483                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1484                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1485                 return $url;
1486         }
1487
1488         /**
1489          * HTML-escaped version of getCanonicalURL()
1490          *
1491          * See getLocalURL for the arguments.
1492          *
1493          * @see self::getLocalURL
1494          * @since 1.18
1495          * @return string
1496          */
1497         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1498                 wfDeprecated( __METHOD__, '1.19' );
1499                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1500         }
1501
1502         /**
1503          * Get the edit URL for this Title
1504          *
1505          * @return String the URL, or a null string if this is an
1506          *  interwiki link
1507          */
1508         public function getEditURL() {
1509                 if ( $this->mInterwiki != '' ) {
1510                         return '';
1511                 }
1512                 $s = $this->getLocalURL( 'action=edit' );
1513
1514                 return $s;
1515         }
1516
1517         /**
1518          * Is $wgUser watching this page?
1519          *
1520          * @deprecated in 1.20; use User::isWatched() instead.
1521          * @return Bool
1522          */
1523         public function userIsWatching() {
1524                 global $wgUser;
1525
1526                 if ( is_null( $this->mWatched ) ) {
1527                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1528                                 $this->mWatched = false;
1529                         } else {
1530                                 $this->mWatched = $wgUser->isWatched( $this );
1531                         }
1532                 }
1533                 return $this->mWatched;
1534         }
1535
1536         /**
1537          * Can $wgUser read this page?
1538          *
1539          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1540          * @return Bool
1541          * @todo fold these checks into userCan()
1542          */
1543         public function userCanRead() {
1544                 wfDeprecated( __METHOD__, '1.19' );
1545                 return $this->userCan( 'read' );
1546         }
1547
1548         /**
1549          * Can $user perform $action on this page?
1550          * This skips potentially expensive cascading permission checks
1551          * as well as avoids expensive error formatting
1552          *
1553          * Suitable for use for nonessential UI controls in common cases, but
1554          * _not_ for functional access control.
1555          *
1556          * May provide false positives, but should never provide a false negative.
1557          *
1558          * @param $action String action that permission needs to be checked for
1559          * @param $user User to check (since 1.19); $wgUser will be used if not
1560          *              provided.
1561          * @return Bool
1562          */
1563         public function quickUserCan( $action, $user = null ) {
1564                 return $this->userCan( $action, $user, false );
1565         }
1566
1567         /**
1568          * Can $user perform $action on this page?
1569          *
1570          * @param $action String action that permission needs to be checked for
1571          * @param $user User to check (since 1.19); $wgUser will be used if not
1572          *   provided.
1573          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1574          *   unnecessary queries.
1575          * @return Bool
1576          */
1577         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1578                 if ( !$user instanceof User ) {
1579                         global $wgUser;
1580                         $user = $wgUser;
1581                 }
1582                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1583         }
1584
1585         /**
1586          * Can $user perform $action on this page?
1587          *
1588          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1589          *
1590          * @param $action String action that permission needs to be checked for
1591          * @param $user User to check
1592          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1593          *   queries by skipping checks for cascading protections and user blocks.
1594          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1595          *   whose corresponding errors may be ignored.
1596          * @return Array of arguments to wfMessage to explain permissions problems.
1597          */
1598         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1599                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1600
1601                 // Remove the errors being ignored.
1602                 foreach ( $errors as $index => $error ) {
1603                         $error_key = is_array( $error ) ? $error[0] : $error;
1604
1605                         if ( in_array( $error_key, $ignoreErrors ) ) {
1606                                 unset( $errors[$index] );
1607                         }
1608                 }
1609
1610                 return $errors;
1611         }
1612
1613         /**
1614          * Permissions checks that fail most often, and which are easiest to test.
1615          *
1616          * @param $action String the action to check
1617          * @param $user User user to check
1618          * @param $errors Array list of current errors
1619          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1620          * @param $short Boolean short circuit on first error
1621          *
1622          * @return Array list of errors
1623          */
1624         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1625                 if ( $action == 'create' ) {
1626                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1627                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1628                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1629                         }
1630                 } elseif ( $action == 'move' ) {
1631                         if ( !$user->isAllowed( 'move-rootuserpages' )
1632                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1633                                 // Show user page-specific message only if the user can move other pages
1634                                 $errors[] = array( 'cant-move-user-page' );
1635                         }
1636
1637                         // Check if user is allowed to move files if it's a file
1638                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1639                                 $errors[] = array( 'movenotallowedfile' );
1640                         }
1641
1642                         if ( !$user->isAllowed( 'move' ) ) {
1643                                 // User can't move anything
1644                                 global $wgGroupPermissions;
1645                                 $userCanMove = false;
1646                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1647                                         $userCanMove = $wgGroupPermissions['user']['move'];
1648                                 }
1649                                 $autoconfirmedCanMove = false;
1650                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1651                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1652                                 }
1653                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1654                                         // custom message if logged-in users without any special rights can move
1655                                         $errors[] = array( 'movenologintext' );
1656                                 } else {
1657                                         $errors[] = array( 'movenotallowed' );
1658                                 }
1659                         }
1660                 } elseif ( $action == 'move-target' ) {
1661                         if ( !$user->isAllowed( 'move' ) ) {
1662                                 // User can't move anything
1663                                 $errors[] = array( 'movenotallowed' );
1664                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1665                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1666                                 // Show user page-specific message only if the user can move other pages
1667                                 $errors[] = array( 'cant-move-to-user-page' );
1668                         }
1669                 } elseif ( !$user->isAllowed( $action ) ) {
1670                         $errors[] = $this->missingPermissionError( $action, $short );
1671                 }
1672
1673                 return $errors;
1674         }
1675
1676         /**
1677          * Add the resulting error code to the errors array
1678          *
1679          * @param $errors Array list of current errors
1680          * @param $result Mixed result of errors
1681          *
1682          * @return Array list of errors
1683          */
1684         private function resultToError( $errors, $result ) {
1685                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1686                         // A single array representing an error
1687                         $errors[] = $result;
1688                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1689                         // A nested array representing multiple errors
1690                         $errors = array_merge( $errors, $result );
1691                 } elseif ( $result !== '' && is_string( $result ) ) {
1692                         // A string representing a message-id
1693                         $errors[] = array( $result );
1694                 } elseif ( $result === false ) {
1695                         // a generic "We don't want them to do that"
1696                         $errors[] = array( 'badaccess-group0' );
1697                 }
1698                 return $errors;
1699         }
1700
1701         /**
1702          * Check various permission hooks
1703          *
1704          * @param $action String the action to check
1705          * @param $user User user to check
1706          * @param $errors Array list of current errors
1707          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1708          * @param $short Boolean short circuit on first error
1709          *
1710          * @return Array list of errors
1711          */
1712         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1713                 // Use getUserPermissionsErrors instead
1714                 $result = '';
1715                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1716                         return $result ? array() : array( array( 'badaccess-group0' ) );
1717                 }
1718                 // Check getUserPermissionsErrors hook
1719                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1720                         $errors = $this->resultToError( $errors, $result );
1721                 }
1722                 // Check getUserPermissionsErrorsExpensive hook
1723                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1724                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1725                         $errors = $this->resultToError( $errors, $result );
1726                 }
1727
1728                 return $errors;
1729         }
1730
1731         /**
1732          * Check permissions on special pages & namespaces
1733          *
1734          * @param $action String the action to check
1735          * @param $user User user to check
1736          * @param $errors Array list of current errors
1737          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1738          * @param $short Boolean short circuit on first error
1739          *
1740          * @return Array list of errors
1741          */
1742         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1743                 # Only 'createaccount' and 'execute' can be performed on
1744                 # special pages, which don't actually exist in the DB.
1745                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1746                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1747                         $errors[] = array( 'ns-specialprotected' );
1748                 }
1749
1750                 # Check $wgNamespaceProtection for restricted namespaces
1751                 if ( $this->isNamespaceProtected( $user ) ) {
1752                         $ns = $this->mNamespace == NS_MAIN ?
1753                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
1754                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1755                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1756                 }
1757
1758                 return $errors;
1759         }
1760
1761         /**
1762          * Check CSS/JS sub-page permissions
1763          *
1764          * @param $action String the action to check
1765          * @param $user User user to check
1766          * @param $errors Array list of current errors
1767          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1768          * @param $short Boolean short circuit on first error
1769          *
1770          * @return Array list of errors
1771          */
1772         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1773                 # Protect css/js subpages of user pages
1774                 # XXX: this might be better using restrictions
1775                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1776                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1777                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1778                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1779                                 $errors[] = array( 'customcssprotected' );
1780                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1781                                 $errors[] = array( 'customjsprotected' );
1782                         }
1783                 }
1784
1785                 return $errors;
1786         }
1787
1788         /**
1789          * Check against page_restrictions table requirements on this
1790          * page. The user must possess all required rights for this
1791          * action.
1792          *
1793          * @param $action String the action to check
1794          * @param $user User user to check
1795          * @param $errors Array list of current errors
1796          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1797          * @param $short Boolean short circuit on first error
1798          *
1799          * @return Array list of errors
1800          */
1801         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1802                 foreach ( $this->getRestrictions( $action ) as $right ) {
1803                         // Backwards compatibility, rewrite sysop -> protect
1804                         if ( $right == 'sysop' ) {
1805                                 $right = 'protect';
1806                         }
1807                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1808                                 // Users with 'editprotected' permission can edit protected pages
1809                                 // without cascading option turned on.
1810                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1811                                         || $this->mCascadeRestriction )
1812                                 {
1813                                         $errors[] = array( 'protectedpagetext', $right );
1814                                 }
1815                         }
1816                 }
1817
1818                 return $errors;
1819         }
1820
1821         /**
1822          * Check restrictions on cascading pages.
1823          *
1824          * @param $action String the action to check
1825          * @param $user User to check
1826          * @param $errors Array list of current errors
1827          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1828          * @param $short Boolean short circuit on first error
1829          *
1830          * @return Array list of errors
1831          */
1832         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1833                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1834                         # We /could/ use the protection level on the source page, but it's
1835                         # fairly ugly as we have to establish a precedence hierarchy for pages
1836                         # included by multiple cascade-protected pages. So just restrict
1837                         # it to people with 'protect' permission, as they could remove the
1838                         # protection anyway.
1839                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1840                         # Cascading protection depends on more than this page...
1841                         # Several cascading protected pages may include this page...
1842                         # Check each cascading level
1843                         # This is only for protection restrictions, not for all actions
1844                         if ( isset( $restrictions[$action] ) ) {
1845                                 foreach ( $restrictions[$action] as $right ) {
1846                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1847                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1848                                                 $pages = '';
1849                                                 foreach ( $cascadingSources as $page )
1850                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1851                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1852                                         }
1853                                 }
1854                         }
1855                 }
1856
1857                 return $errors;
1858         }
1859
1860         /**
1861          * Check action permissions not already checked in checkQuickPermissions
1862          *
1863          * @param $action String the action to check
1864          * @param $user User to check
1865          * @param $errors Array list of current errors
1866          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1867          * @param $short Boolean short circuit on first error
1868          *
1869          * @return Array list of errors
1870          */
1871         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1872                 global $wgDeleteRevisionsLimit, $wgLang;
1873
1874                 if ( $action == 'protect' ) {
1875                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1876                                 // If they can't edit, they shouldn't protect.
1877                                 $errors[] = array( 'protect-cantedit' );
1878                         }
1879                 } elseif ( $action == 'create' ) {
1880                         $title_protection = $this->getTitleProtection();
1881                         if( $title_protection ) {
1882                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1883                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1884                                 }
1885                                 if( $title_protection['pt_create_perm'] == '' ||
1886                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1887                                 {
1888                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1889                                 }
1890                         }
1891                 } elseif ( $action == 'move' ) {
1892                         // Check for immobile pages
1893                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1894                                 // Specific message for this case
1895                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1896                         } elseif ( !$this->isMovable() ) {
1897                                 // Less specific message for rarer cases
1898                                 $errors[] = array( 'immobile-source-page' );
1899                         }
1900                 } elseif ( $action == 'move-target' ) {
1901                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1902                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1903                         } elseif ( !$this->isMovable() ) {
1904                                 $errors[] = array( 'immobile-target-page' );
1905                         }
1906                 } elseif ( $action == 'delete' ) {
1907                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1908                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1909                         {
1910                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1911                         }
1912                 }
1913                 return $errors;
1914         }
1915
1916         /**
1917          * Check that the user isn't blocked from editting.
1918          *
1919          * @param $action String the action to check
1920          * @param $user User to check
1921          * @param $errors Array list of current errors
1922          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1923          * @param $short Boolean short circuit on first error
1924          *
1925          * @return Array list of errors
1926          */
1927         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1928                 // Account creation blocks handled at userlogin.
1929                 // Unblocking handled in SpecialUnblock
1930                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1931                         return $errors;
1932                 }
1933
1934                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1935
1936                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1937                         $errors[] = array( 'confirmedittext' );
1938                 }
1939
1940                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1941                         // Don't block the user from editing their own talk page unless they've been
1942                         // explicitly blocked from that too.
1943                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1944                         $block = $user->getBlock();
1945
1946                         // This is from OutputPage::blockedPage
1947                         // Copied at r23888 by werdna
1948
1949                         $id = $user->blockedBy();
1950                         $reason = $user->blockedFor();
1951                         if ( $reason == '' ) {
1952                                 $reason = wfMessage( 'blockednoreason' )->text();
1953                         }
1954                         $ip = $user->getRequest()->getIP();
1955
1956                         if ( is_numeric( $id ) ) {
1957                                 $name = User::whoIs( $id );
1958                         } else {
1959                                 $name = $id;
1960                         }
1961
1962                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1963                         $blockid = $block->getId();
1964                         $blockExpiry = $block->getExpiry();
1965                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
1966                         if ( $blockExpiry == 'infinity' ) {
1967                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1968                         } else {
1969                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1970                         }
1971
1972                         $intended = strval( $block->getTarget() );
1973
1974                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1975                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1976                 }
1977
1978                 return $errors;
1979         }
1980
1981         /**
1982          * Check that the user is allowed to read this page.
1983          *
1984          * @param $action String the action to check
1985          * @param $user User to check
1986          * @param $errors Array list of current errors
1987          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1988          * @param $short Boolean short circuit on first error
1989          *
1990          * @return Array list of errors
1991          */
1992         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1993                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
1994                 static $useShortcut = null;
1995
1996                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1997                 if ( is_null( $useShortcut ) ) {
1998                         $useShortcut = true;
1999                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
2000                                 # Not a public wiki, so no shortcut
2001                                 $useShortcut = false;
2002                         } elseif ( !empty( $wgRevokePermissions ) ) {
2003                                 /**
2004                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2005                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2006                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2007                                  * reading is allowed.
2008                                  */
2009                                 foreach ( $wgRevokePermissions as $perms ) {
2010                                         if ( !empty( $perms['read'] ) ) {
2011                                                 # We might be removing the read right from the user, so no shortcut
2012                                                 $useShortcut = false;
2013                                                 break;
2014                                         }
2015                                 }
2016                         }
2017                 }
2018
2019                 $whitelisted = false;
2020                 if ( $useShortcut ) {
2021                         # Shortcut for public wikis, allows skipping quite a bit of code
2022                         $whitelisted = true;
2023                 } elseif ( $user->isAllowed( 'read' ) ) {
2024                         # If the user is allowed to read pages, he is allowed to read all pages
2025                         $whitelisted = true;
2026                 } elseif ( $this->isSpecial( 'Userlogin' )
2027                         || $this->isSpecial( 'ChangePassword' )
2028                         || $this->isSpecial( 'PasswordReset' )
2029                 ) {
2030                         # Always grant access to the login page.
2031                         # Even anons need to be able to log in.
2032                         $whitelisted = true;
2033                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2034                         # Time to check the whitelist
2035                         # Only do these checks is there's something to check against
2036                         $name = $this->getPrefixedText();
2037                         $dbName = $this->getPrefixedDBKey();
2038
2039                         // Check for explicit whitelisting with and without underscores
2040                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2041                                 $whitelisted = true;
2042                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2043                                 # Old settings might have the title prefixed with
2044                                 # a colon for main-namespace pages
2045                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2046                                         $whitelisted = true;
2047                                 }
2048                         } elseif ( $this->isSpecialPage() ) {
2049                                 # If it's a special page, ditch the subpage bit and check again
2050                                 $name = $this->getDBkey();
2051                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2052                                 if ( $name !== false ) {
2053                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2054                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2055                                                 $whitelisted = true;
2056                                         }
2057                                 }
2058                         }
2059                 }
2060
2061                 if ( !$whitelisted ) {
2062                         # If the title is not whitelisted, give extensions a chance to do so...
2063                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2064                         if ( !$whitelisted ) {
2065                                 $errors[] = $this->missingPermissionError( $action, $short );
2066                         }
2067                 }
2068
2069                 return $errors;
2070         }
2071
2072         /**
2073          * Get a description array when the user doesn't have the right to perform
2074          * $action (i.e. when User::isAllowed() returns false)
2075          *
2076          * @param $action String the action to check
2077          * @param $short Boolean short circuit on first error
2078          * @return Array list of errors
2079          */
2080         private function missingPermissionError( $action, $short ) {
2081                 // We avoid expensive display logic for quickUserCan's and such
2082                 if ( $short ) {
2083                         return array( 'badaccess-group0' );
2084                 }
2085
2086                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2087                         User::getGroupsWithPermission( $action ) );
2088
2089                 if ( count( $groups ) ) {
2090                         global $wgLang;
2091                         return array(
2092                                 'badaccess-groups',
2093                                 $wgLang->commaList( $groups ),
2094                                 count( $groups )
2095                         );
2096                 } else {
2097                         return array( 'badaccess-group0' );
2098                 }
2099         }
2100
2101         /**
2102          * Can $user perform $action on this page? This is an internal function,
2103          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2104          * checks on wfReadOnly() and blocks)
2105          *
2106          * @param $action String action that permission needs to be checked for
2107          * @param $user User to check
2108          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2109          * @param $short Bool Set this to true to stop after the first permission error.
2110          * @return Array of arrays of the arguments to wfMessage to explain permissions problems.
2111          */
2112         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2113                 wfProfileIn( __METHOD__ );
2114
2115                 # Read has special handling
2116                 if ( $action == 'read' ) {
2117                         $checks = array(
2118                                 'checkPermissionHooks',
2119                                 'checkReadPermissions',
2120                         );
2121                 } else {
2122                         $checks = array(
2123                                 'checkQuickPermissions',
2124                                 'checkPermissionHooks',
2125                                 'checkSpecialsAndNSPermissions',
2126                                 'checkCSSandJSPermissions',
2127                                 'checkPageRestrictions',
2128                                 'checkCascadingSourcesRestrictions',
2129                                 'checkActionPermissions',
2130                                 'checkUserBlock'
2131                         );
2132                 }
2133
2134                 $errors = array();
2135                 while( count( $checks ) > 0 &&
2136                                 !( $short && count( $errors ) > 0 ) ) {
2137                         $method = array_shift( $checks );
2138                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2139                 }
2140
2141                 wfProfileOut( __METHOD__ );
2142                 return $errors;
2143         }
2144
2145         /**
2146          * Protect css subpages of user pages: can $wgUser edit
2147          * this page?
2148          *
2149          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2150          * @return Bool
2151          */
2152         public function userCanEditCssSubpage() {
2153                 global $wgUser;
2154                 wfDeprecated( __METHOD__, '1.19' );
2155                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2156                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2157         }
2158
2159         /**
2160          * Protect js subpages of user pages: can $wgUser edit
2161          * this page?
2162          *
2163          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2164          * @return Bool
2165          */
2166         public function userCanEditJsSubpage() {
2167                 global $wgUser;
2168                 wfDeprecated( __METHOD__, '1.19' );
2169                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2170                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2171         }
2172
2173         /**
2174          * Get a filtered list of all restriction types supported by this wiki.
2175          * @param bool $exists True to get all restriction types that apply to
2176          * titles that do exist, False for all restriction types that apply to
2177          * titles that do not exist
2178          * @return array
2179          */
2180         public static function getFilteredRestrictionTypes( $exists = true ) {
2181                 global $wgRestrictionTypes;
2182                 $types = $wgRestrictionTypes;
2183                 if ( $exists ) {
2184                         # Remove the create restriction for existing titles
2185                         $types = array_diff( $types, array( 'create' ) );
2186                 } else {
2187                         # Only the create and upload restrictions apply to non-existing titles
2188                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2189                 }
2190                 return $types;
2191         }
2192
2193         /**
2194          * Returns restriction types for the current Title
2195          *
2196          * @return array applicable restriction types
2197          */
2198         public function getRestrictionTypes() {
2199                 if ( $this->isSpecialPage() ) {
2200                         return array();
2201                 }
2202
2203                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2204
2205                 if ( $this->getNamespace() != NS_FILE ) {
2206                         # Remove the upload restriction for non-file titles
2207                         $types = array_diff( $types, array( 'upload' ) );
2208                 }
2209
2210                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2211
2212                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2213                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2214
2215                 return $types;
2216         }
2217
2218         /**
2219          * Is this title subject to title protection?
2220          * Title protection is the one applied against creation of such title.
2221          *
2222          * @return Mixed An associative array representing any existent title
2223          *   protection, or false if there's none.
2224          */
2225         private function getTitleProtection() {
2226                 // Can't protect pages in special namespaces
2227                 if ( $this->getNamespace() < 0 ) {
2228                         return false;
2229                 }
2230
2231                 // Can't protect pages that exist.
2232                 if ( $this->exists() ) {
2233                         return false;
2234                 }
2235
2236                 if ( !isset( $this->mTitleProtection ) ) {
2237                         $dbr = wfGetDB( DB_SLAVE );
2238                         $res = $dbr->select( 'protected_titles', '*',
2239                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2240                                 __METHOD__ );
2241
2242                         // fetchRow returns false if there are no rows.
2243                         $this->mTitleProtection = $dbr->fetchRow( $res );
2244                 }
2245                 return $this->mTitleProtection;
2246         }
2247
2248         /**
2249          * Update the title protection status
2250          *
2251          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2252          * @param $create_perm String Permission required for creation
2253          * @param $reason String Reason for protection
2254          * @param $expiry String Expiry timestamp
2255          * @return boolean true
2256          */
2257         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2258                 wfDeprecated( __METHOD__, '1.19' );
2259
2260                 global $wgUser;
2261
2262                 $limit = array( 'create' => $create_perm );
2263                 $expiry = array( 'create' => $expiry );
2264
2265                 $page = WikiPage::factory( $this );
2266                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2267
2268                 return $status->isOK();
2269         }
2270
2271         /**
2272          * Remove any title protection due to page existing
2273          */
2274         public function deleteTitleProtection() {
2275                 $dbw = wfGetDB( DB_MASTER );
2276
2277                 $dbw->delete(
2278                         'protected_titles',
2279                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2280                         __METHOD__
2281                 );
2282                 $this->mTitleProtection = false;
2283         }
2284
2285         /**
2286          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2287          *
2288          * @param $action String Action to check (default: edit)
2289          * @return Bool
2290          */
2291         public function isSemiProtected( $action = 'edit' ) {
2292                 if ( $this->exists() ) {
2293                         $restrictions = $this->getRestrictions( $action );
2294                         if ( count( $restrictions ) > 0 ) {
2295                                 foreach ( $restrictions as $restriction ) {
2296                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2297                                                 return false;
2298                                         }
2299                                 }
2300                         } else {
2301                                 # Not protected
2302                                 return false;
2303                         }
2304                         return true;
2305                 } else {
2306                         # If it doesn't exist, it can't be protected
2307                         return false;
2308                 }
2309         }
2310
2311         /**
2312          * Does the title correspond to a protected article?
2313          *
2314          * @param $action String the action the page is protected from,
2315          * by default checks all actions.
2316          * @return Bool
2317          */
2318         public function isProtected( $action = '' ) {
2319                 global $wgRestrictionLevels;
2320
2321                 $restrictionTypes = $this->getRestrictionTypes();
2322
2323                 # Special pages have inherent protection
2324                 if( $this->isSpecialPage() ) {
2325                         return true;
2326                 }
2327
2328                 # Check regular protection levels
2329                 foreach ( $restrictionTypes as $type ) {
2330                         if ( $action == $type || $action == '' ) {
2331                                 $r = $this->getRestrictions( $type );
2332                                 foreach ( $wgRestrictionLevels as $level ) {
2333                                         if ( in_array( $level, $r ) && $level != '' ) {
2334                                                 return true;
2335                                         }
2336                                 }
2337                         }
2338                 }
2339
2340                 return false;
2341         }
2342
2343         /**
2344          * Determines if $user is unable to edit this page because it has been protected
2345          * by $wgNamespaceProtection.
2346          *
2347          * @param $user User object to check permissions
2348          * @return Bool
2349          */
2350         public function isNamespaceProtected( User $user ) {
2351                 global $wgNamespaceProtection;
2352
2353                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2354                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2355                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2356                                         return true;
2357                                 }
2358                         }
2359                 }
2360                 return false;
2361         }
2362
2363         /**
2364          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2365          *
2366          * @return Bool If the page is subject to cascading restrictions.
2367          */
2368         public function isCascadeProtected() {
2369                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2370                 return ( $sources > 0 );
2371         }
2372
2373         /**
2374          * Cascading protection: Get the source of any cascading restrictions on this page.
2375          *
2376          * @param $getPages Bool Whether or not to retrieve the actual pages
2377          *        that the restrictions have come from.
2378          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2379          *     have come, false for none, or true if such restrictions exist, but $getPages
2380          *     was not set.  The restriction array is an array of each type, each of which
2381          *     contains a array of unique groups.
2382          */
2383         public function getCascadeProtectionSources( $getPages = true ) {
2384                 global $wgContLang;
2385                 $pagerestrictions = array();
2386
2387                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2388                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2389                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2390                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2391                 }
2392
2393                 wfProfileIn( __METHOD__ );
2394
2395                 $dbr = wfGetDB( DB_SLAVE );
2396
2397                 if ( $this->getNamespace() == NS_FILE ) {
2398                         $tables = array( 'imagelinks', 'page_restrictions' );
2399                         $where_clauses = array(
2400                                 'il_to' => $this->getDBkey(),
2401                                 'il_from=pr_page',
2402                                 'pr_cascade' => 1
2403                         );
2404                 } else {
2405                         $tables = array( 'templatelinks', 'page_restrictions' );
2406                         $where_clauses = array(
2407                                 'tl_namespace' => $this->getNamespace(),
2408                                 'tl_title' => $this->getDBkey(),
2409                                 'tl_from=pr_page',
2410                                 'pr_cascade' => 1
2411                         );
2412                 }
2413
2414                 if ( $getPages ) {
2415                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2416                                                    'pr_expiry', 'pr_type', 'pr_level' );
2417                         $where_clauses[] = 'page_id=pr_page';
2418                         $tables[] = 'page';
2419                 } else {
2420                         $cols = array( 'pr_expiry' );
2421                 }
2422
2423                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2424
2425                 $sources = $getPages ? array() : false;
2426                 $now = wfTimestampNow();
2427                 $purgeExpired = false;
2428
2429                 foreach ( $res as $row ) {
2430                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2431                         if ( $expiry > $now ) {
2432                                 if ( $getPages ) {
2433                                         $page_id = $row->pr_page;
2434                                         $page_ns = $row->page_namespace;
2435                                         $page_title = $row->page_title;
2436                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2437                                         # Add groups needed for each restriction type if its not already there
2438                                         # Make sure this restriction type still exists
2439
2440                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2441                                                 $pagerestrictions[$row->pr_type] = array();
2442                                         }
2443
2444                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2445                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2446                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2447                                         }
2448                                 } else {
2449                                         $sources = true;
2450                                 }
2451                         } else {
2452                                 // Trigger lazy purge of expired restrictions from the db
2453                                 $purgeExpired = true;
2454                         }
2455                 }
2456                 if ( $purgeExpired ) {
2457                         Title::purgeExpiredRestrictions();
2458                 }
2459
2460                 if ( $getPages ) {
2461                         $this->mCascadeSources = $sources;
2462                         $this->mCascadingRestrictions = $pagerestrictions;
2463                 } else {
2464                         $this->mHasCascadingRestrictions = $sources;
2465                 }
2466
2467                 wfProfileOut( __METHOD__ );
2468                 return array( $sources, $pagerestrictions );
2469         }
2470
2471         /**
2472          * Accessor/initialisation for mRestrictions
2473          *
2474          * @param $action String action that permission needs to be checked for
2475          * @return Array of Strings the array of groups allowed to edit this article
2476          */
2477         public function getRestrictions( $action ) {
2478                 if ( !$this->mRestrictionsLoaded ) {
2479                         $this->loadRestrictions();
2480                 }
2481                 return isset( $this->mRestrictions[$action] )
2482                                 ? $this->mRestrictions[$action]
2483                                 : array();
2484         }
2485
2486         /**
2487          * Get the expiry time for the restriction against a given action
2488          *
2489          * @param $action
2490          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2491          *     or not protected at all, or false if the action is not recognised.
2492          */
2493         public function getRestrictionExpiry( $action ) {
2494                 if ( !$this->mRestrictionsLoaded ) {
2495                         $this->loadRestrictions();
2496                 }
2497                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2498         }
2499
2500         /**
2501          * Returns cascading restrictions for the current article
2502          *
2503          * @return Boolean
2504          */
2505         function areRestrictionsCascading() {
2506                 if ( !$this->mRestrictionsLoaded ) {
2507                         $this->loadRestrictions();
2508                 }
2509
2510                 return $this->mCascadeRestriction;
2511         }
2512
2513         /**
2514          * Loads a string into mRestrictions array
2515          *
2516          * @param $res Resource restrictions as an SQL result.
2517          * @param $oldFashionedRestrictions String comma-separated list of page
2518          *        restrictions from page table (pre 1.10)
2519          */
2520         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2521                 $rows = array();
2522
2523                 foreach ( $res as $row ) {
2524                         $rows[] = $row;
2525                 }
2526
2527                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2528         }
2529
2530         /**
2531          * Compiles list of active page restrictions from both page table (pre 1.10)
2532          * and page_restrictions table for this existing page.
2533          * Public for usage by LiquidThreads.
2534          *
2535          * @param $rows array of db result objects
2536          * @param $oldFashionedRestrictions string comma-separated list of page
2537          *        restrictions from page table (pre 1.10)
2538          */
2539         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2540                 global $wgContLang;
2541                 $dbr = wfGetDB( DB_SLAVE );
2542
2543                 $restrictionTypes = $this->getRestrictionTypes();
2544
2545                 foreach ( $restrictionTypes as $type ) {
2546                         $this->mRestrictions[$type] = array();
2547                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2548                 }
2549
2550                 $this->mCascadeRestriction = false;
2551
2552                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2553
2554                 if ( $oldFashionedRestrictions === null ) {
2555                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2556                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2557                 }
2558
2559                 if ( $oldFashionedRestrictions != '' ) {
2560
2561                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2562                                 $temp = explode( '=', trim( $restrict ) );
2563                                 if ( count( $temp ) == 1 ) {
2564                                         // old old format should be treated as edit/move restriction
2565                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2566                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2567                                 } else {
2568                                         $restriction = trim( $temp[1] );
2569                                         if( $restriction != '' ) { //some old entries are empty
2570                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2571                                         }
2572                                 }
2573                         }
2574
2575                         $this->mOldRestrictions = true;
2576
2577                 }
2578
2579                 if ( count( $rows ) ) {
2580                         # Current system - load second to make them override.
2581                         $now = wfTimestampNow();
2582                         $purgeExpired = false;
2583
2584                         # Cycle through all the restrictions.
2585                         foreach ( $rows as $row ) {
2586
2587                                 // Don't take care of restrictions types that aren't allowed
2588                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2589                                         continue;
2590
2591                                 // This code should be refactored, now that it's being used more generally,
2592                                 // But I don't really see any harm in leaving it in Block for now -werdna
2593                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2594
2595                                 // Only apply the restrictions if they haven't expired!
2596                                 if ( !$expiry || $expiry > $now ) {
2597                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2598                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2599
2600                                         $this->mCascadeRestriction |= $row->pr_cascade;
2601                                 } else {
2602                                         // Trigger a lazy purge of expired restrictions
2603                                         $purgeExpired = true;
2604                                 }
2605                         }
2606
2607                         if ( $purgeExpired ) {
2608                                 Title::purgeExpiredRestrictions();
2609                         }
2610                 }
2611
2612                 $this->mRestrictionsLoaded = true;
2613         }
2614
2615         /**
2616          * Load restrictions from the page_restrictions table
2617          *
2618          * @param $oldFashionedRestrictions String comma-separated list of page
2619          *        restrictions from page table (pre 1.10)
2620          */
2621         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2622                 global $wgContLang;
2623                 if ( !$this->mRestrictionsLoaded ) {
2624                         if ( $this->exists() ) {
2625                                 $dbr = wfGetDB( DB_SLAVE );
2626
2627                                 $res = $dbr->select(
2628                                         'page_restrictions',
2629                                         '*',
2630                                         array( 'pr_page' => $this->getArticleID() ),
2631                                         __METHOD__
2632                                 );
2633
2634                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2635                         } else {
2636                                 $title_protection = $this->getTitleProtection();
2637
2638                                 if ( $title_protection ) {
2639                                         $now = wfTimestampNow();
2640                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2641
2642                                         if ( !$expiry || $expiry > $now ) {
2643                                                 // Apply the restrictions
2644                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2645                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2646                                         } else { // Get rid of the old restrictions
2647                                                 Title::purgeExpiredRestrictions();
2648                                                 $this->mTitleProtection = false;
2649                                         }
2650                                 } else {
2651                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2652                                 }
2653                                 $this->mRestrictionsLoaded = true;
2654                         }
2655                 }
2656         }
2657
2658         /**
2659          * Flush the protection cache in this object and force reload from the database.
2660          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2661          */
2662         public function flushRestrictions() {
2663                 $this->mRestrictionsLoaded = false;
2664                 $this->mTitleProtection = null;
2665         }
2666
2667         /**
2668          * Purge expired restrictions from the page_restrictions table
2669          */
2670         static function purgeExpiredRestrictions() {
2671                 $dbw = wfGetDB( DB_MASTER );
2672                 $dbw->delete(
2673                         'page_restrictions',
2674                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2675                         __METHOD__
2676                 );
2677
2678                 $dbw->delete(
2679                         'protected_titles',
2680                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2681                         __METHOD__
2682                 );
2683         }
2684
2685         /**
2686          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2687          *
2688          * @return Bool
2689          */
2690         public function hasSubpages() {
2691                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2692                         # Duh
2693                         return false;
2694                 }
2695
2696                 # We dynamically add a member variable for the purpose of this method
2697                 # alone to cache the result.  There's no point in having it hanging
2698                 # around uninitialized in every Title object; therefore we only add it
2699                 # if needed and don't declare it statically.
2700                 if ( isset( $this->mHasSubpages ) ) {
2701                         return $this->mHasSubpages;
2702                 }
2703
2704                 $subpages = $this->getSubpages( 1 );
2705                 if ( $subpages instanceof TitleArray ) {
2706                         return $this->mHasSubpages = (bool)$subpages->count();
2707                 }
2708                 return $this->mHasSubpages = false;
2709         }
2710
2711         /**
2712          * Get all subpages of this page.
2713          *
2714          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2715          * @return mixed TitleArray, or empty array if this page's namespace
2716          *  doesn't allow subpages
2717          */
2718         public function getSubpages( $limit = -1 ) {
2719                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2720                         return array();
2721                 }
2722
2723                 $dbr = wfGetDB( DB_SLAVE );
2724                 $conds['page_namespace'] = $this->getNamespace();
2725                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2726                 $options = array();
2727                 if ( $limit > -1 ) {
2728                         $options['LIMIT'] = $limit;
2729                 }
2730                 return $this->mSubpages = TitleArray::newFromResult(
2731                         $dbr->select( 'page',
2732                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2733                                 $conds,
2734                                 __METHOD__,
2735                                 $options
2736                         )
2737                 );
2738         }
2739
2740         /**
2741          * Is there a version of this page in the deletion archive?
2742          *
2743          * @return Int the number of archived revisions
2744          */
2745         public function isDeleted() {
2746                 if ( $this->getNamespace() < 0 ) {
2747                         $n = 0;
2748                 } else {
2749                         $dbr = wfGetDB( DB_SLAVE );
2750
2751                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2752                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2753                                 __METHOD__
2754                         );
2755                         if ( $this->getNamespace() == NS_FILE ) {
2756                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2757                                         array( 'fa_name' => $this->getDBkey() ),
2758                                         __METHOD__
2759                                 );
2760                         }
2761                 }
2762                 return (int)$n;
2763         }
2764
2765         /**
2766          * Is there a version of this page in the deletion archive?
2767          *
2768          * @return Boolean
2769          */
2770         public function isDeletedQuick() {
2771                 if ( $this->getNamespace() < 0 ) {
2772                         return false;
2773                 }
2774                 $dbr = wfGetDB( DB_SLAVE );
2775                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2776                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2777                         __METHOD__
2778                 );
2779                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2780                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2781                                 array( 'fa_name' => $this->getDBkey() ),
2782                                 __METHOD__
2783                         );
2784                 }
2785                 return $deleted;
2786         }
2787
2788         /**
2789          * Get the article ID for this Title from the link cache,
2790          * adding it if necessary
2791          *
2792          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2793          *  for update
2794          * @return Int the ID
2795          */
2796         public function getArticleID( $flags = 0 ) {
2797                 if ( $this->getNamespace() < 0 ) {
2798                         return $this->mArticleID = 0;
2799                 }
2800                 $linkCache = LinkCache::singleton();
2801                 if ( $flags & self::GAID_FOR_UPDATE ) {
2802                         $oldUpdate = $linkCache->forUpdate( true );
2803                         $linkCache->clearLink( $this );
2804                         $this->mArticleID = $linkCache->addLinkObj( $this );
2805                         $linkCache->forUpdate( $oldUpdate );
2806                 } else {
2807                         if ( -1 == $this->mArticleID ) {
2808                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2809                         }
2810                 }
2811                 return $this->mArticleID;
2812         }
2813
2814         /**
2815          * Is this an article that is a redirect page?
2816          * Uses link cache, adding it if necessary
2817          *
2818          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2819          * @return Bool
2820          */
2821         public function isRedirect( $flags = 0 ) {
2822                 if ( !is_null( $this->mRedirect ) ) {
2823                         return $this->mRedirect;
2824                 }
2825                 # Calling getArticleID() loads the field from cache as needed
2826                 if ( !$this->getArticleID( $flags ) ) {
2827                         return $this->mRedirect = false;
2828                 }
2829                 $linkCache = LinkCache::singleton();
2830                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2831
2832                 return $this->mRedirect;
2833         }
2834
2835         /**
2836          * What is the length of this page?
2837          * Uses link cache, adding it if necessary
2838          *
2839          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2840          * @return Int
2841          */
2842         public function getLength( $flags = 0 ) {
2843                 if ( $this->mLength != -1 ) {
2844                         return $this->mLength;
2845                 }
2846                 # Calling getArticleID() loads the field from cache as needed
2847                 if ( !$this->getArticleID( $flags ) ) {
2848                         return $this->mLength = 0;
2849                 }
2850                 $linkCache = LinkCache::singleton();
2851                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2852
2853                 return $this->mLength;
2854         }
2855
2856         /**
2857          * What is the page_latest field for this page?
2858          *
2859          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2860          * @return Int or 0 if the page doesn't exist
2861          */
2862         public function getLatestRevID( $flags = 0 ) {
2863                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
2864                         return intval( $this->mLatestID );
2865                 }
2866                 # Calling getArticleID() loads the field from cache as needed
2867                 if ( !$this->getArticleID( $flags ) ) {
2868                         return $this->mLatestID = 0;
2869                 }
2870                 $linkCache = LinkCache::singleton();
2871                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2872
2873                 return $this->mLatestID;
2874         }
2875
2876         /**
2877          * This clears some fields in this object, and clears any associated
2878          * keys in the "bad links" section of the link cache.
2879          *
2880          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2881          * loading of the new page_id. It's also called from
2882          * WikiPage::doDeleteArticleReal()
2883          *
2884          * @param $newid Int the new Article ID
2885          */
2886         public function resetArticleID( $newid ) {
2887                 $linkCache = LinkCache::singleton();
2888                 $linkCache->clearLink( $this );
2889
2890                 if ( $newid === false ) {
2891                         $this->mArticleID = -1;
2892                 } else {
2893                         $this->mArticleID = intval( $newid );
2894                 }
2895                 $this->mRestrictionsLoaded = false;
2896                 $this->mRestrictions = array();
2897                 $this->mRedirect = null;
2898                 $this->mLength = -1;
2899                 $this->mLatestID = false;
2900                 $this->mEstimateRevisions = null;
2901         }
2902
2903         /**
2904          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2905          *
2906          * @param $text String containing title to capitalize
2907          * @param $ns int namespace index, defaults to NS_MAIN
2908          * @return String containing capitalized title
2909          */
2910         public static function capitalize( $text, $ns = NS_MAIN ) {
2911                 global $wgContLang;
2912
2913                 if ( MWNamespace::isCapitalized( $ns ) ) {
2914                         return $wgContLang->ucfirst( $text );
2915                 } else {
2916                         return $text;
2917                 }
2918         }
2919
2920         /**
2921          * Secure and split - main initialisation function for this object
2922          *
2923          * Assumes that mDbkeyform has been set, and is urldecoded
2924          * and uses underscores, but not otherwise munged.  This function
2925          * removes illegal characters, splits off the interwiki and
2926          * namespace prefixes, sets the other forms, and canonicalizes
2927          * everything.
2928          *
2929          * @return Bool true on success
2930          */
2931         private function secureAndSplit() {
2932                 global $wgContLang, $wgLocalInterwiki;
2933
2934                 # Initialisation
2935                 $this->mInterwiki = $this->mFragment = '';
2936                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2937
2938                 $dbkey = $this->mDbkeyform;
2939
2940                 # Strip Unicode bidi override characters.
2941                 # Sometimes they slip into cut-n-pasted page titles, where the
2942                 # override chars get included in list displays.
2943                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2944
2945                 # Clean up whitespace
2946                 # Note: use of the /u option on preg_replace here will cause
2947                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2948                 # conveniently disabling them.
2949                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2950                 $dbkey = trim( $dbkey, '_' );
2951
2952                 if ( $dbkey == '' ) {
2953                         return false;
2954                 }
2955
2956                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2957                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2958                         return false;
2959                 }
2960
2961                 $this->mDbkeyform = $dbkey;
2962
2963                 # Initial colon indicates main namespace rather than specified default
2964                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2965                 if ( ':' == $dbkey[0] ) {
2966                         $this->mNamespace = NS_MAIN;
2967                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2968                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2969                 }
2970
2971                 # Namespace or interwiki prefix
2972                 $firstPass = true;
2973                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2974                 do {
2975                         $m = array();
2976                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2977                                 $p = $m[1];
2978                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2979                                         # Ordinary namespace
2980                                         $dbkey = $m[2];
2981                                         $this->mNamespace = $ns;
2982                                         # For Talk:X pages, check if X has a "namespace" prefix
2983                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2984                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2985                                                         # Disallow Talk:File:x type titles...
2986                                                         return false;
2987                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2988                                                         # Disallow Talk:Interwiki:x type titles...
2989                                                         return false;
2990                                                 }
2991                                         }
2992                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2993                                         if ( !$firstPass ) {
2994                                                 # Can't make a local interwiki link to an interwiki link.
2995                                                 # That's just crazy!
2996                                                 return false;
2997                                         }
2998
2999                                         # Interwiki link
3000                                         $dbkey = $m[2];
3001                                         $this->mInterwiki = $wgContLang->lc( $p );
3002
3003                                         # Redundant interwiki prefix to the local wiki
3004                                         if ( $wgLocalInterwiki !== false
3005                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3006                                         {
3007                                                 if ( $dbkey == '' ) {
3008                                                         # Can't have an empty self-link
3009                                                         return false;
3010                                                 }
3011                                                 $this->mInterwiki = '';
3012                                                 $firstPass = false;
3013                                                 # Do another namespace split...
3014                                                 continue;
3015                                         }
3016
3017                                         # If there's an initial colon after the interwiki, that also
3018                                         # resets the default namespace
3019                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3020                                                 $this->mNamespace = NS_MAIN;
3021                                                 $dbkey = substr( $dbkey, 1 );
3022                                         }
3023                                 }
3024                                 # If there's no recognized interwiki or namespace,
3025                                 # then let the colon expression be part of the title.
3026                         }
3027                         break;
3028                 } while ( true );
3029
3030                 # We already know that some pages won't be in the database!
3031                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3032                         $this->mArticleID = 0;
3033                 }
3034                 $fragment = strstr( $dbkey, '#' );
3035                 if ( false !== $fragment ) {
3036                         $this->setFragment( $fragment );
3037                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3038                         # remove whitespace again: prevents "Foo_bar_#"
3039                         # becoming "Foo_bar_"
3040                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3041                 }
3042
3043                 # Reject illegal characters.
3044                 $rxTc = self::getTitleInvalidRegex();
3045                 if ( preg_match( $rxTc, $dbkey ) ) {
3046                         return false;
3047                 }
3048
3049                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3050                 # reachable due to the way web browsers deal with 'relative' URLs.
3051                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3052                 if ( strpos( $dbkey, '.' ) !== false &&
3053                          ( $dbkey === '.' || $dbkey === '..' ||
3054                            strpos( $dbkey, './' ) === 0  ||
3055                            strpos( $dbkey, '../' ) === 0 ||
3056                            strpos( $dbkey, '/./' ) !== false ||
3057                            strpos( $dbkey, '/../' ) !== false  ||
3058                            substr( $dbkey, -2 ) == '/.' ||
3059                            substr( $dbkey, -3 ) == '/..' ) )
3060                 {
3061                         return false;
3062                 }
3063
3064                 # Magic tilde sequences? Nu-uh!
3065                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3066                         return false;
3067                 }
3068
3069                 # Limit the size of titles to 255 bytes. This is typically the size of the
3070                 # underlying database field. We make an exception for special pages, which
3071                 # don't need to be stored in the database, and may edge over 255 bytes due
3072                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3073                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3074                   strlen( $dbkey ) > 512 )
3075                 {
3076                         return false;
3077                 }
3078
3079                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3080                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3081                 # other site might be case-sensitive.
3082                 $this->mUserCaseDBKey = $dbkey;
3083                 if ( $this->mInterwiki == '' ) {
3084                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3085                 }
3086
3087                 # Can't make a link to a namespace alone... "empty" local links can only be
3088                 # self-links with a fragment identifier.
3089                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3090                         return false;
3091                 }
3092
3093                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3094                 // IP names are not allowed for accounts, and can only be referring to
3095                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3096                 // there are numerous ways to present the same IP. Having sp:contribs scan
3097                 // them all is silly and having some show the edits and others not is
3098                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3099                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3100                         ? IP::sanitizeIP( $dbkey )
3101                         : $dbkey;
3102
3103                 // Any remaining initial :s are illegal.
3104                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3105                         return false;
3106                 }
3107
3108                 # Fill fields
3109                 $this->mDbkeyform = $dbkey;
3110                 $this->mUrlform = wfUrlencode( $dbkey );
3111
3112                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3113
3114                 return true;
3115         }
3116
3117         /**
3118          * Get an array of Title objects linking to this Title
3119          * Also stores the IDs in the link cache.
3120          *
3121          * WARNING: do not use this function on arbitrary user-supplied titles!
3122          * On heavily-used templates it will max out the memory.
3123          *
3124          * @param $options Array: may be FOR UPDATE
3125          * @param $table String: table name
3126          * @param $prefix String: fields prefix
3127          * @return Array of Title objects linking here
3128          */
3129         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3130                 if ( count( $options ) > 0 ) {
3131                         $db = wfGetDB( DB_MASTER );
3132                 } else {
3133                         $db = wfGetDB( DB_SLAVE );
3134                 }
3135
3136                 $res = $db->select(
3137                         array( 'page', $table ),
3138                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3139                         array(
3140                                 "{$prefix}_from=page_id",
3141                                 "{$prefix}_namespace" => $this->getNamespace(),
3142                                 "{$prefix}_title"     => $this->getDBkey() ),
3143                         __METHOD__,
3144                         $options
3145                 );
3146
3147                 $retVal = array();
3148                 if ( $res->numRows() ) {
3149                         $linkCache = LinkCache::singleton();
3150                         foreach ( $res as $row ) {
3151                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3152                                 if ( $titleObj ) {
3153                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3154                                         $retVal[] = $titleObj;
3155                                 }
3156                         }
3157                 }
3158                 return $retVal;
3159         }
3160
3161         /**
3162          * Get an array of Title objects using this Title as a template
3163          * Also stores the IDs in the link cache.
3164          *
3165          * WARNING: do not use this function on arbitrary user-supplied titles!
3166          * On heavily-used templates it will max out the memory.
3167          *
3168          * @param $options Array: may be FOR UPDATE
3169          * @return Array of Title the Title objects linking here
3170          */
3171         public function getTemplateLinksTo( $options = array() ) {
3172                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3173         }
3174
3175         /**
3176          * Get an array of Title objects linked from this Title
3177          * Also stores the IDs in the link cache.
3178          *
3179          * WARNING: do not use this function on arbitrary user-supplied titles!
3180          * On heavily-used templates it will max out the memory.
3181          *
3182          * @param $options Array: may be FOR UPDATE
3183          * @param $table String: table name
3184          * @param $prefix String: fields prefix
3185          * @return Array of Title objects linking here
3186          */
3187         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3188                 $id = $this->getArticleID();
3189
3190                 # If the page doesn't exist; there can't be any link from this page
3191                 if ( !$id ) {
3192                         return array();
3193                 }
3194
3195                 if ( count( $options ) > 0 ) {
3196                         $db = wfGetDB( DB_MASTER );
3197                 } else {
3198                         $db = wfGetDB( DB_SLAVE );
3199                 }
3200
3201                 $namespaceFiled = "{$prefix}_namespace";
3202                 $titleField = "{$prefix}_title";
3203
3204                 $res = $db->select(
3205                         array( $table, 'page' ),
3206                         array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3207                         array( "{$prefix}_from" => $id ),
3208                         __METHOD__,
3209                         $options,
3210                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3211                 );
3212
3213                 $retVal = array();
3214                 if ( $res->numRows() ) {
3215                         $linkCache = LinkCache::singleton();
3216                         foreach ( $res as $row ) {
3217                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3218                                 if ( $titleObj ) {
3219                                         if ( $row->page_id ) {
3220                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3221                                         } else {
3222                                                 $linkCache->addBadLinkObj( $titleObj );
3223                                         }
3224                                         $retVal[] = $titleObj;
3225                                 }
3226                         }
3227                 }
3228                 return $retVal;
3229         }
3230
3231         /**
3232          * Get an array of Title objects used on this Title as a template
3233          * Also stores the IDs in the link cache.
3234          *
3235          * WARNING: do not use this function on arbitrary user-supplied titles!
3236          * On heavily-used templates it will max out the memory.
3237          *
3238          * @param $options Array: may be FOR UPDATE
3239          * @return Array of Title the Title objects used here
3240          */
3241         public function getTemplateLinksFrom( $options = array() ) {
3242                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3243         }
3244
3245         /**
3246          * Get an array of Title objects referring to non-existent articles linked from this page
3247          *
3248          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3249          * @return Array of Title the Title objects
3250          */
3251         public function getBrokenLinksFrom() {
3252                 if ( $this->getArticleID() == 0 ) {
3253                         # All links from article ID 0 are false positives
3254                         return array();
3255                 }
3256
3257                 $dbr = wfGetDB( DB_SLAVE );
3258                 $res = $dbr->select(
3259                         array( 'page', 'pagelinks' ),
3260                         array( 'pl_namespace', 'pl_title' ),
3261                         array(
3262                                 'pl_from' => $this->getArticleID(),
3263                                 'page_namespace IS NULL'
3264                         ),
3265                         __METHOD__, array(),
3266                         array(
3267                                 'page' => array(
3268                                         'LEFT JOIN',
3269                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3270                                 )
3271                         )
3272                 );
3273
3274                 $retVal = array();
3275                 foreach ( $res as $row ) {
3276                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3277                 }
3278                 return $retVal;
3279         }
3280
3281
3282         /**
3283          * Get a list of URLs to purge from the Squid cache when this
3284          * page changes
3285          *
3286          * @return Array of String the URLs
3287          */
3288         public function getSquidURLs() {
3289                 $urls = array(
3290                         $this->getInternalURL(),
3291                         $this->getInternalURL( 'action=history' )
3292                 );
3293
3294                 $pageLang = $this->getPageLanguage();
3295                 if ( $pageLang->hasVariants() ) {
3296                         $variants = $pageLang->getVariants();
3297                         foreach ( $variants as $vCode ) {
3298                                 $urls[] = $this->getInternalURL( '', $vCode );
3299                         }
3300                 }
3301
3302                 return $urls;
3303         }
3304
3305         /**
3306          * Purge all applicable Squid URLs
3307          */
3308         public function purgeSquid() {
3309                 global $wgUseSquid;
3310                 if ( $wgUseSquid ) {
3311                         $urls = $this->getSquidURLs();
3312                         $u = new SquidUpdate( $urls );
3313                         $u->doUpdate();
3314                 }
3315         }
3316
3317         /**
3318          * Move this page without authentication
3319          *
3320          * @param $nt Title the new page Title
3321          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3322          */
3323         public function moveNoAuth( &$nt ) {
3324                 return $this->moveTo( $nt, false );
3325         }
3326
3327         /**
3328          * Check whether a given move operation would be valid.
3329          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3330          *
3331          * @param $nt Title the new title
3332          * @param $auth Bool indicates whether $wgUser's permissions
3333          *  should be checked
3334          * @param $reason String is the log summary of the move, used for spam checking
3335          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3336          */
3337         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3338                 global $wgUser;
3339
3340                 $errors = array();
3341                 if ( !$nt ) {
3342                         // Normally we'd add this to $errors, but we'll get
3343                         // lots of syntax errors if $nt is not an object
3344                         return array( array( 'badtitletext' ) );
3345                 }
3346                 if ( $this->equals( $nt ) ) {
3347                         $errors[] = array( 'selfmove' );
3348                 }
3349                 if ( !$this->isMovable() ) {
3350                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3351                 }
3352                 if ( $nt->getInterwiki() != '' ) {
3353                         $errors[] = array( 'immobile-target-namespace-iw' );
3354                 }
3355                 if ( !$nt->isMovable() ) {
3356                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3357                 }
3358
3359                 $oldid = $this->getArticleID();
3360                 $newid = $nt->getArticleID();
3361
3362                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3363                         $errors[] = array( 'articleexists' );
3364                 }
3365                 if ( ( $this->getDBkey() == '' ) ||
3366                          ( !$oldid ) ||
3367                          ( $nt->getDBkey() == '' ) ) {
3368                         $errors[] = array( 'badarticleerror' );
3369                 }
3370
3371                 // Image-specific checks
3372                 if ( $this->getNamespace() == NS_FILE ) {
3373                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3374                 }
3375
3376                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3377                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3378                 }
3379
3380                 if ( $auth ) {
3381                         $errors = wfMergeErrorArrays( $errors,
3382                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3383                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3384                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3385                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3386                 }
3387
3388                 $match = EditPage::matchSummarySpamRegex( $reason );
3389                 if ( $match !== false ) {
3390                         // This is kind of lame, won't display nice
3391                         $errors[] = array( 'spamprotectiontext' );
3392                 }
3393
3394                 $err = null;
3395                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3396                         $errors[] = array( 'hookaborted', $err );
3397                 }
3398
3399                 # The move is allowed only if (1) the target doesn't exist, or
3400                 # (2) the target is a redirect to the source, and has no history
3401                 # (so we can undo bad moves right after they're done).
3402
3403                 if ( 0 != $newid ) { # Target exists; check for validity
3404                         if ( !$this->isValidMoveTarget( $nt ) ) {
3405                                 $errors[] = array( 'articleexists' );
3406                         }
3407                 } else {
3408                         $tp = $nt->getTitleProtection();
3409                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3410                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3411                                 $errors[] = array( 'cantmove-titleprotected' );
3412                         }
3413                 }
3414                 if ( empty( $errors ) ) {
3415                         return true;
3416                 }
3417                 return $errors;
3418         }
3419
3420         /**
3421          * Check if the requested move target is a valid file move target
3422          * @param Title $nt Target title
3423          * @return array List of errors
3424          */
3425         protected function validateFileMoveOperation( $nt ) {
3426                 global $wgUser;
3427
3428                 $errors = array();
3429
3430                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3431
3432                 $file = wfLocalFile( $this );
3433                 if ( $file->exists() ) {
3434                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3435                                 $errors[] = array( 'imageinvalidfilename' );
3436                         }
3437                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3438                                 $errors[] = array( 'imagetypemismatch' );
3439                         }
3440                 }
3441
3442                 if ( $nt->getNamespace() != NS_FILE ) {
3443                         $errors[] = array( 'imagenocrossnamespace' );
3444                         // From here we want to do checks on a file object, so if we can't
3445                         // create one, we must return.
3446                         return $errors;
3447                 }
3448
3449                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3450
3451                 $destFile = wfLocalFile( $nt );
3452                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3453                         $errors[] = array( 'file-exists-sharedrepo' );
3454                 }
3455
3456                 return $errors;
3457         }
3458
3459         /**
3460          * Move a title to a new location
3461          *
3462          * @param $nt Title the new title
3463          * @param $auth Bool indicates whether $wgUser's permissions
3464          *  should be checked
3465          * @param $reason String the reason for the move
3466          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3467          *  Ignored if the user doesn't have the suppressredirect right.
3468          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3469          */
3470         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3471                 global $wgUser;
3472                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3473                 if ( is_array( $err ) ) {
3474                         // Auto-block user's IP if the account was "hard" blocked
3475                         $wgUser->spreadAnyEditBlock();
3476                         return $err;
3477                 }
3478                 // Check suppressredirect permission
3479                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3480                         $createRedirect = true;
3481                 }
3482
3483                 // If it is a file, move it first.
3484                 // It is done before all other moving stuff is done because it's hard to revert.
3485                 $dbw = wfGetDB( DB_MASTER );
3486                 if ( $this->getNamespace() == NS_FILE ) {
3487                         $file = wfLocalFile( $this );
3488                         if ( $file->exists() ) {
3489                                 $status = $file->move( $nt );
3490                                 if ( !$status->isOk() ) {
3491                                         return $status->getErrorsArray();
3492                                 }
3493                         }
3494                         // Clear RepoGroup process cache
3495                         RepoGroup::singleton()->clearCache( $this );
3496                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3497                 }
3498
3499                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3500                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3501                 $protected = $this->isProtected();
3502
3503                 // Do the actual move
3504                 $this->moveToInternal( $nt, $reason, $createRedirect );
3505
3506                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3507                 // cl_timestamp, which may disturb time-based lists on some sites.
3508                 $prefixes = $dbw->select(
3509                         'categorylinks',
3510                         array( 'cl_sortkey_prefix', 'cl_to' ),
3511                         array( 'cl_from' => $pageid ),
3512                         __METHOD__
3513                 );
3514                 foreach ( $prefixes as $prefixRow ) {
3515                         $prefix = $prefixRow->cl_sortkey_prefix;
3516                         $catTo = $prefixRow->cl_to;
3517                         $dbw->update( 'categorylinks',
3518                                 array(
3519                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3520                                                 $nt->getCategorySortkey( $prefix ) ),
3521                                         'cl_timestamp=cl_timestamp' ),
3522                                 array(
3523                                         'cl_from' => $pageid,
3524                                         'cl_to' => $catTo ),
3525                                 __METHOD__
3526                         );
3527                 }
3528
3529                 $redirid = $this->getArticleID();
3530
3531                 if ( $protected ) {
3532                         # Protect the redirect title as the title used to be...
3533                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3534                                 array(
3535                                         'pr_page'    => $redirid,
3536                                         'pr_type'    => 'pr_type',
3537                                         'pr_level'   => 'pr_level',
3538                                         'pr_cascade' => 'pr_cascade',
3539                                         'pr_user'    => 'pr_user',
3540                                         'pr_expiry'  => 'pr_expiry'
3541                                 ),
3542                                 array( 'pr_page' => $pageid ),
3543                                 __METHOD__,
3544                                 array( 'IGNORE' )
3545                         );
3546                         # Update the protection log
3547                         $log = new LogPage( 'protect' );
3548                         $comment = wfMessage(
3549                                 'prot_1movedto2',
3550                                 $this->getPrefixedText(),
3551                                 $nt->getPrefixedText()
3552                         )->inContentLanguage()->text();
3553                         if ( $reason ) {
3554                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3555                         }
3556                         // @todo FIXME: $params?
3557                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3558                 }
3559
3560                 # Update watchlists
3561                 $oldnamespace = $this->getNamespace() & ~1;
3562                 $newnamespace = $nt->getNamespace() & ~1;
3563                 $oldtitle = $this->getDBkey();
3564                 $newtitle = $nt->getDBkey();
3565
3566                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3567                         WatchedItem::duplicateEntries( $this, $nt );
3568                 }
3569
3570                 $dbw->commit( __METHOD__ );
3571
3572                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3573                 return true;
3574         }
3575
3576         /**
3577          * Move page to a title which is either a redirect to the
3578          * source page or nonexistent
3579          *
3580          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3581          * @param $reason String The reason for the move
3582          * @param $createRedirect Bool Whether to leave a redirect at the old title. Does not check
3583          *   if the user has the suppressredirect right
3584          * @throws MWException
3585          */
3586         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3587                 global $wgUser, $wgContLang;
3588
3589                 if ( $nt->exists() ) {
3590                         $moveOverRedirect = true;
3591                         $logType = 'move_redir';
3592                 } else {
3593                         $moveOverRedirect = false;
3594                         $logType = 'move';
3595                 }
3596
3597                 $redirectSuppressed = !$createRedirect;
3598
3599                 $logEntry = new ManualLogEntry( 'move', $logType );
3600                 $logEntry->setPerformer( $wgUser );
3601                 $logEntry->setTarget( $this );
3602                 $logEntry->setComment( $reason );
3603                 $logEntry->setParameters( array(
3604                         '4::target' => $nt->getPrefixedText(),
3605                         '5::noredir' => $redirectSuppressed ? '1': '0',
3606                 ) );
3607
3608                 $formatter = LogFormatter::newFromEntry( $logEntry );
3609                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3610                 $comment = $formatter->getPlainActionText();
3611                 if ( $reason ) {
3612                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3613                 }
3614                 # Truncate for whole multibyte characters.
3615                 $comment = $wgContLang->truncate( $comment, 255 );
3616
3617                 $oldid = $this->getArticleID();
3618
3619                 $dbw = wfGetDB( DB_MASTER );
3620
3621                 $newpage = WikiPage::factory( $nt );
3622
3623                 if ( $moveOverRedirect ) {
3624                         $newid = $nt->getArticleID();
3625
3626                         # Delete the old redirect. We don't save it to history since
3627                         # by definition if we've got here it's rather uninteresting.
3628                         # We have to remove it so that the next step doesn't trigger
3629                         # a conflict on the unique namespace+title index...
3630                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3631
3632                         $newpage->doDeleteUpdates( $newid );
3633                 }
3634
3635                 # Save a null revision in the page's history notifying of the move
3636                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3637                 if ( !is_object( $nullRevision ) ) {
3638                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3639                 }
3640                 $nullRevId = $nullRevision->insertOn( $dbw );
3641
3642                 # Change the name of the target page:
3643                 $dbw->update( 'page',
3644                         /* SET */ array(
3645                                 'page_namespace' => $nt->getNamespace(),
3646                                 'page_title'     => $nt->getDBkey(),
3647                         ),
3648                         /* WHERE */ array( 'page_id' => $oldid ),
3649                         __METHOD__
3650                 );
3651
3652                 $this->resetArticleID( 0 );
3653                 $nt->resetArticleID( $oldid );
3654
3655                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3656
3657                 wfRunHooks( 'NewRevisionFromEditComplete',
3658                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3659
3660                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3661
3662                 if ( !$moveOverRedirect ) {
3663                         WikiPage::onArticleCreate( $nt );
3664                 }
3665
3666                 # Recreate the redirect, this time in the other direction.
3667                 if ( $redirectSuppressed ) {
3668                         WikiPage::onArticleDelete( $this );
3669                 } else {
3670                         $mwRedir = MagicWord::get( 'redirect' );
3671                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3672                         $redirectArticle = WikiPage::factory( $this );
3673                         $newid = $redirectArticle->insertOn( $dbw );
3674                         if ( $newid ) { // sanity
3675                                 $redirectRevision = new Revision( array(
3676                                         'page'    => $newid,
3677                                         'comment' => $comment,
3678                                         'text'    => $redirectText ) );
3679                                 $redirectRevision->insertOn( $dbw );
3680                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3681
3682                                 wfRunHooks( 'NewRevisionFromEditComplete',
3683                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3684
3685                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3686                         }
3687                 }
3688
3689                 # Log the move
3690                 $logid = $logEntry->insert();
3691                 $logEntry->publish( $logid );
3692         }
3693
3694         /**
3695          * Move this page's subpages to be subpages of $nt
3696          *
3697          * @param $nt Title Move target
3698          * @param $auth bool Whether $wgUser's permissions should be checked
3699          * @param $reason string The reason for the move
3700          * @param $createRedirect bool Whether to create redirects from the old subpages to
3701          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3702          * @return mixed array with old page titles as keys, and strings (new page titles) or
3703          *     arrays (errors) as values, or an error array with numeric indices if no pages
3704          *     were moved
3705          */
3706         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3707                 global $wgMaximumMovedPages;
3708                 // Check permissions
3709                 if ( !$this->userCan( 'move-subpages' ) ) {
3710                         return array( 'cant-move-subpages' );
3711                 }
3712                 // Do the source and target namespaces support subpages?
3713                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3714                         return array( 'namespace-nosubpages',
3715                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3716                 }
3717                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3718                         return array( 'namespace-nosubpages',
3719                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3720                 }
3721
3722                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3723                 $retval = array();
3724                 $count = 0;
3725                 foreach ( $subpages as $oldSubpage ) {
3726                         $count++;
3727                         if ( $count > $wgMaximumMovedPages ) {
3728                                 $retval[$oldSubpage->getPrefixedTitle()] =
3729                                                 array( 'movepage-max-pages',
3730                                                         $wgMaximumMovedPages );
3731                                 break;
3732                         }
3733
3734                         // We don't know whether this function was called before
3735                         // or after moving the root page, so check both
3736                         // $this and $nt
3737                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3738                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3739                         {
3740                                 // When moving a page to a subpage of itself,
3741                                 // don't move it twice
3742                                 continue;
3743                         }
3744                         $newPageName = preg_replace(
3745                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3746                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3747                                         $oldSubpage->getDBkey() );
3748                         if ( $oldSubpage->isTalkPage() ) {
3749                                 $newNs = $nt->getTalkPage()->getNamespace();
3750                         } else {
3751                                 $newNs = $nt->getSubjectPage()->getNamespace();
3752                         }
3753                         # Bug 14385: we need makeTitleSafe because the new page names may
3754                         # be longer than 255 characters.
3755                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3756
3757                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3758                         if ( $success === true ) {
3759                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3760                         } else {
3761                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3762                         }
3763                 }
3764                 return $retval;
3765         }
3766
3767         /**
3768          * Checks if this page is just a one-rev redirect.
3769          * Adds lock, so don't use just for light purposes.
3770          *
3771          * @return Bool
3772          */
3773         public function isSingleRevRedirect() {
3774                 $dbw = wfGetDB( DB_MASTER );
3775                 # Is it a redirect?
3776                 $row = $dbw->selectRow( 'page',
3777                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3778                         $this->pageCond(),
3779                         __METHOD__,
3780                         array( 'FOR UPDATE' )
3781                 );
3782                 # Cache some fields we may want
3783                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3784                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3785                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3786                 if ( !$this->mRedirect ) {
3787                         return false;
3788                 }
3789                 # Does the article have a history?
3790                 $row = $dbw->selectField( array( 'page', 'revision' ),
3791                         'rev_id',
3792                         array( 'page_namespace' => $this->getNamespace(),
3793                                 'page_title' => $this->getDBkey(),
3794                                 'page_id=rev_page',
3795                                 'page_latest != rev_id'
3796                         ),
3797                         __METHOD__,
3798                         array( 'FOR UPDATE' )
3799                 );
3800                 # Return true if there was no history
3801                 return ( $row === false );
3802         }
3803
3804         /**
3805          * Checks if $this can be moved to a given Title
3806          * - Selects for update, so don't call it unless you mean business
3807          *
3808          * @param $nt Title the new title to check
3809          * @return Bool
3810          */
3811         public function isValidMoveTarget( $nt ) {
3812                 # Is it an existing file?
3813                 if ( $nt->getNamespace() == NS_FILE ) {
3814                         $file = wfLocalFile( $nt );
3815                         if ( $file->exists() ) {
3816                                 wfDebug( __METHOD__ . ": file exists\n" );
3817                                 return false;
3818                         }
3819                 }
3820                 # Is it a redirect with no history?
3821                 if ( !$nt->isSingleRevRedirect() ) {
3822                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3823                         return false;
3824                 }
3825                 # Get the article text
3826                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3827                 if( !is_object( $rev ) ){
3828                         return false;
3829                 }
3830                 $text = $rev->getText();
3831                 # Does the redirect point to the source?
3832                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3833                 $m = array();
3834                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3835                         $redirTitle = Title::newFromText( $m[1] );
3836                         if ( !is_object( $redirTitle ) ||
3837                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3838                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3839                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3840                                 return false;
3841                         }
3842                 } else {
3843                         # Fail safe
3844                         wfDebug( __METHOD__ . ": failsafe\n" );
3845                         return false;
3846                 }
3847                 return true;
3848         }
3849
3850         /**
3851          * Get categories to which this Title belongs and return an array of
3852          * categories' names.
3853          *
3854          * @return Array of parents in the form:
3855          *        $parent => $currentarticle
3856          */
3857         public function getParentCategories() {
3858                 global $wgContLang;
3859
3860                 $data = array();
3861
3862                 $titleKey = $this->getArticleID();
3863
3864                 if ( $titleKey === 0 ) {
3865                         return $data;
3866                 }
3867
3868                 $dbr = wfGetDB( DB_SLAVE );
3869
3870                 $res = $dbr->select( 'categorylinks', '*',
3871                         array(
3872                                 'cl_from' => $titleKey,
3873                         ),
3874                         __METHOD__,
3875                         array()
3876                 );
3877
3878                 if ( $dbr->numRows( $res ) > 0 ) {
3879                         foreach ( $res as $row ) {
3880                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3881                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3882                         }
3883                 }
3884                 return $data;
3885         }
3886
3887         /**
3888          * Get a tree of parent categories
3889          *
3890          * @param $children Array with the children in the keys, to check for circular refs
3891          * @return Array Tree of parent categories
3892          */
3893         public function getParentCategoryTree( $children = array() ) {
3894                 $stack = array();
3895                 $parents = $this->getParentCategories();
3896
3897                 if ( $parents ) {
3898                         foreach ( $parents as $parent => $current ) {
3899                                 if ( array_key_exists( $parent, $children ) ) {
3900                                         # Circular reference
3901                                         $stack[$parent] = array();
3902                                 } else {
3903                                         $nt = Title::newFromText( $parent );
3904                                         if ( $nt ) {
3905                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3906                                         }
3907                                 }
3908                         }
3909                 }
3910
3911                 return $stack;
3912         }
3913
3914         /**
3915          * Get an associative array for selecting this title from
3916          * the "page" table
3917          *
3918          * @return Array suitable for the $where parameter of DB::select()
3919          */
3920         public function pageCond() {
3921                 if ( $this->mArticleID > 0 ) {
3922                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3923                         return array( 'page_id' => $this->mArticleID );
3924                 } else {
3925                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3926                 }
3927         }
3928
3929         /**
3930          * Get the revision ID of the previous revision
3931          *
3932          * @param $revId Int Revision ID. Get the revision that was before this one.
3933          * @param $flags Int Title::GAID_FOR_UPDATE
3934          * @return Int|Bool Old revision ID, or FALSE if none exists
3935          */
3936         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3937                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3938                 $revId = $db->selectField( 'revision', 'rev_id',
3939                         array(
3940                                 'rev_page' => $this->getArticleID( $flags ),
3941                                 'rev_id < ' . intval( $revId )
3942                         ),
3943                         __METHOD__,
3944                         array( 'ORDER BY' => 'rev_id DESC' )
3945                 );
3946
3947                 if ( $revId === false ) {
3948                         return false;
3949                 } else {
3950                         return intval( $revId );
3951                 }
3952         }
3953
3954         /**
3955          * Get the revision ID of the next revision
3956          *
3957          * @param $revId Int Revision ID. Get the revision that was after this one.
3958          * @param $flags Int Title::GAID_FOR_UPDATE
3959          * @return Int|Bool Next revision ID, or FALSE if none exists
3960          */
3961         public function getNextRevisionID( $revId, $flags = 0 ) {
3962                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3963                 $revId = $db->selectField( 'revision', 'rev_id',
3964                         array(
3965                                 'rev_page' => $this->getArticleID( $flags ),
3966                                 'rev_id > ' . intval( $revId )
3967                         ),
3968                         __METHOD__,
3969                         array( 'ORDER BY' => 'rev_id' )
3970                 );
3971
3972                 if ( $revId === false ) {
3973                         return false;
3974                 } else {
3975                         return intval( $revId );
3976                 }
3977         }
3978
3979         /**
3980          * Get the first revision of the page
3981          *
3982          * @param $flags Int Title::GAID_FOR_UPDATE
3983          * @return Revision|Null if page doesn't exist
3984          */
3985         public function getFirstRevision( $flags = 0 ) {
3986                 $pageId = $this->getArticleID( $flags );
3987                 if ( $pageId ) {
3988                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3989                         $row = $db->selectRow( 'revision', Revision::selectFields(),
3990                                 array( 'rev_page' => $pageId ),
3991                                 __METHOD__,
3992                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3993                         );
3994                         if ( $row ) {
3995                                 return new Revision( $row );
3996                         }
3997                 }
3998                 return null;
3999         }
4000
4001         /**
4002          * Get the oldest revision timestamp of this page
4003          *
4004          * @param $flags Int Title::GAID_FOR_UPDATE
4005          * @return String: MW timestamp
4006          */
4007         public function getEarliestRevTime( $flags = 0 ) {
4008                 $rev = $this->getFirstRevision( $flags );
4009                 return $rev ? $rev->getTimestamp() : null;
4010         }
4011
4012         /**
4013          * Check if this is a new page
4014          *
4015          * @return bool
4016          */
4017         public function isNewPage() {
4018                 $dbr = wfGetDB( DB_SLAVE );
4019                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4020         }
4021
4022         /**
4023          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4024          *
4025          * @return bool
4026          */
4027         public function isBigDeletion() {
4028                 global $wgDeleteRevisionsLimit;
4029
4030                 if ( !$wgDeleteRevisionsLimit ) {
4031                         return false;
4032                 }
4033
4034                 $revCount = $this->estimateRevisionCount();
4035                 return $revCount > $wgDeleteRevisionsLimit;
4036         }
4037
4038         /**
4039          * Get the  approximate revision count of this page.
4040          *
4041          * @return int
4042          */
4043         public function estimateRevisionCount() {
4044                 if ( !$this->exists() ) {
4045                         return 0;
4046                 }
4047
4048                 if ( $this->mEstimateRevisions === null ) {
4049                         $dbr = wfGetDB( DB_SLAVE );
4050                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4051                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4052                 }
4053
4054                 return $this->mEstimateRevisions;
4055         }
4056
4057         /**
4058          * Get the number of revisions between the given revision.
4059          * Used for diffs and other things that really need it.
4060          *
4061          * @param $old int|Revision Old revision or rev ID (first before range)
4062          * @param $new int|Revision New revision or rev ID (first after range)
4063          * @return Int Number of revisions between these revisions.
4064          */
4065         public function countRevisionsBetween( $old, $new ) {
4066                 if ( !( $old instanceof Revision ) ) {
4067                         $old = Revision::newFromTitle( $this, (int)$old );
4068                 }
4069                 if ( !( $new instanceof Revision ) ) {
4070                         $new = Revision::newFromTitle( $this, (int)$new );
4071                 }
4072                 if ( !$old || !$new ) {
4073                         return 0; // nothing to compare
4074                 }
4075                 $dbr = wfGetDB( DB_SLAVE );
4076                 return (int)$dbr->selectField( 'revision', 'count(*)',
4077                         array(
4078                                 'rev_page' => $this->getArticleID(),
4079                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4080                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4081                         ),
4082                         __METHOD__
4083                 );
4084         }
4085
4086         /**
4087          * Get the number of authors between the given revisions or revision IDs.
4088          * Used for diffs and other things that really need it.
4089          *
4090          * @param $old int|Revision Old revision or rev ID (first before range by default)
4091          * @param $new int|Revision New revision or rev ID (first after range by default)
4092          * @param $limit int Maximum number of authors
4093          * @param $options string|array (Optional): Single option, or an array of options:
4094          *     'include_old' Include $old in the range; $new is excluded.
4095          *     'include_new' Include $new in the range; $old is excluded.
4096          *     'include_both' Include both $old and $new in the range.
4097          *     Unknown option values are ignored.
4098          * @return int Number of revision authors in the range; zero if not both revisions exist
4099          */
4100         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4101                 if ( !( $old instanceof Revision ) ) {
4102                         $old = Revision::newFromTitle( $this, (int)$old );
4103                 }
4104                 if ( !( $new instanceof Revision ) ) {
4105                         $new = Revision::newFromTitle( $this, (int)$new );
4106                 }
4107                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4108                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4109                 // in the sanity check below?
4110                 if ( !$old || !$new ) {
4111                         return 0; // nothing to compare
4112                 }
4113                 $old_cmp = '>';
4114                 $new_cmp = '<';
4115                 $options = (array) $options;
4116                 if ( in_array( 'include_old', $options ) ) {
4117                         $old_cmp = '>=';
4118                 }
4119                 if ( in_array( 'include_new', $options ) ) {
4120                         $new_cmp = '<=';
4121                 }
4122                 if ( in_array( 'include_both', $options ) ) {
4123                         $old_cmp = '>=';
4124                         $new_cmp = '<=';
4125                 }
4126                 // No DB query needed if $old and $new are the same or successive revisions:
4127                 if ( $old->getId() === $new->getId() ) {
4128                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4129                 } else if ( $old->getId() === $new->getParentId() ) {
4130                         if ( $old_cmp === '>' || $new_cmp === '<' ) {
4131                                 return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4132                         }
4133                         return ( $old->getRawUserText() === $new->getRawUserText() ) ? 1 : 2;
4134                 }
4135                 $dbr = wfGetDB( DB_SLAVE );
4136                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4137                         array(
4138                                 'rev_page' => $this->getArticleID(),
4139                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4140                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4141                         ), __METHOD__,
4142                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4143                 );
4144                 return (int)$dbr->numRows( $res );
4145         }
4146
4147         /**
4148          * Compare with another title.
4149          *
4150          * @param $title Title
4151          * @return Bool
4152          */
4153         public function equals( Title $title ) {
4154                 // Note: === is necessary for proper matching of number-like titles.
4155                 return $this->getInterwiki() === $title->getInterwiki()
4156                         && $this->getNamespace() == $title->getNamespace()
4157                         && $this->getDBkey() === $title->getDBkey();
4158         }
4159
4160         /**
4161          * Check if this title is a subpage of another title
4162          *
4163          * @param $title Title
4164          * @return Bool
4165          */
4166         public function isSubpageOf( Title $title ) {
4167                 return $this->getInterwiki() === $title->getInterwiki()
4168                         && $this->getNamespace() == $title->getNamespace()
4169                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4170         }
4171
4172         /**
4173          * Check if page exists.  For historical reasons, this function simply
4174          * checks for the existence of the title in the page table, and will
4175          * thus return false for interwiki links, special pages and the like.
4176          * If you want to know if a title can be meaningfully viewed, you should
4177          * probably call the isKnown() method instead.
4178          *
4179          * @return Bool
4180          */
4181         public function exists() {
4182                 return $this->getArticleID() != 0;
4183         }
4184
4185         /**
4186          * Should links to this title be shown as potentially viewable (i.e. as
4187          * "bluelinks"), even if there's no record by this title in the page
4188          * table?
4189          *
4190          * This function is semi-deprecated for public use, as well as somewhat
4191          * misleadingly named.  You probably just want to call isKnown(), which
4192          * calls this function internally.
4193          *
4194          * (ISSUE: Most of these checks are cheap, but the file existence check
4195          * can potentially be quite expensive.  Including it here fixes a lot of
4196          * existing code, but we might want to add an optional parameter to skip
4197          * it and any other expensive checks.)
4198          *
4199          * @return Bool
4200          */
4201         public function isAlwaysKnown() {
4202                 $isKnown = null;
4203
4204                 /**
4205                  * Allows overriding default behaviour for determining if a page exists.
4206                  * If $isKnown is kept as null, regular checks happen. If it's
4207                  * a boolean, this value is returned by the isKnown method.
4208                  *
4209                  * @since 1.20
4210                  *
4211                  * @param Title $title
4212                  * @param boolean|null $isKnown
4213                  */
4214                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4215
4216                 if ( !is_null( $isKnown ) ) {
4217                         return $isKnown;
4218                 }
4219
4220                 if ( $this->mInterwiki != '' ) {
4221                         return true;  // any interwiki link might be viewable, for all we know
4222                 }
4223
4224                 switch( $this->mNamespace ) {
4225                         case NS_MEDIA:
4226                         case NS_FILE:
4227                                 // file exists, possibly in a foreign repo
4228                                 return (bool)wfFindFile( $this );
4229                         case NS_SPECIAL:
4230                                 // valid special page
4231                                 return SpecialPageFactory::exists( $this->getDBkey() );
4232                         case NS_MAIN:
4233                                 // selflink, possibly with fragment
4234                                 return $this->mDbkeyform == '';
4235                         case NS_MEDIAWIKI:
4236                                 // known system message
4237                                 return $this->hasSourceText() !== false;
4238                         default:
4239                                 return false;
4240                 }
4241         }
4242
4243         /**
4244          * Does this title refer to a page that can (or might) be meaningfully
4245          * viewed?  In particular, this function may be used to determine if
4246          * links to the title should be rendered as "bluelinks" (as opposed to
4247          * "redlinks" to non-existent pages).
4248          * Adding something else to this function will cause inconsistency
4249          * since LinkHolderArray calls isAlwaysKnown() and does its own
4250          * page existence check.
4251          *
4252          * @return Bool
4253          */
4254         public function isKnown() {
4255                 return $this->isAlwaysKnown() || $this->exists();
4256         }
4257
4258         /**
4259          * Does this page have source text?
4260          *
4261          * @return Boolean
4262          */
4263         public function hasSourceText() {
4264                 if ( $this->exists() ) {
4265                         return true;
4266                 }
4267
4268                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4269                         // If the page doesn't exist but is a known system message, default
4270                         // message content will be displayed, same for language subpages-
4271                         // Use always content language to avoid loading hundreds of languages
4272                         // to get the link color.
4273                         global $wgContLang;
4274                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4275                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4276                         return $message->exists();
4277                 }
4278
4279                 return false;
4280         }
4281
4282         /**
4283          * Get the default message text or false if the message doesn't exist
4284          *
4285          * @return String or false
4286          */
4287         public function getDefaultMessageText() {
4288                 global $wgContLang;
4289
4290                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4291                         return false;
4292                 }
4293
4294                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4295                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4296
4297                 if ( $message->exists() ) {
4298                         return $message->plain();
4299                 } else {
4300                         return false;
4301                 }
4302         }
4303
4304         /**
4305          * Updates page_touched for this page; called from LinksUpdate.php
4306          *
4307          * @return Bool true if the update succeded
4308          */
4309         public function invalidateCache() {
4310                 if ( wfReadOnly() ) {
4311                         return false;
4312                 }
4313                 $dbw = wfGetDB( DB_MASTER );
4314                 $success = $dbw->update(
4315                         'page',
4316                         array( 'page_touched' => $dbw->timestamp() ),
4317                         $this->pageCond(),
4318                         __METHOD__
4319                 );
4320                 HTMLFileCache::clearFileCache( $this );
4321                 return $success;
4322         }
4323
4324         /**
4325          * Update page_touched timestamps and send squid purge messages for
4326          * pages linking to this title. May be sent to the job queue depending
4327          * on the number of links. Typically called on create and delete.
4328          */
4329         public function touchLinks() {
4330                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4331                 $u->doUpdate();
4332
4333                 if ( $this->getNamespace() == NS_CATEGORY ) {
4334                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4335                         $u->doUpdate();
4336                 }
4337         }
4338
4339         /**
4340          * Get the last touched timestamp
4341          *
4342          * @param $db DatabaseBase: optional db
4343          * @return String last-touched timestamp
4344          */
4345         public function getTouched( $db = null ) {
4346                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4347                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4348                 return $touched;
4349         }
4350
4351         /**
4352          * Get the timestamp when this page was updated since the user last saw it.
4353          *
4354          * @param $user User
4355          * @return String|Null
4356          */
4357         public function getNotificationTimestamp( $user = null ) {
4358                 global $wgUser, $wgShowUpdatedMarker;
4359                 // Assume current user if none given
4360                 if ( !$user ) {
4361                         $user = $wgUser;
4362                 }
4363                 // Check cache first
4364                 $uid = $user->getId();
4365                 // avoid isset here, as it'll return false for null entries
4366                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4367                         return $this->mNotificationTimestamp[$uid];
4368                 }
4369                 if ( !$uid || !$wgShowUpdatedMarker ) {
4370                         return $this->mNotificationTimestamp[$uid] = false;
4371                 }
4372                 // Don't cache too much!
4373                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4374                         $this->mNotificationTimestamp = array();
4375                 }
4376                 $dbr = wfGetDB( DB_SLAVE );
4377                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4378                         'wl_notificationtimestamp',
4379                         array(
4380                                 'wl_user' => $user->getId(),
4381                                 'wl_namespace' => $this->getNamespace(),
4382                                 'wl_title' => $this->getDBkey(),
4383                         ),
4384                         __METHOD__
4385                 );
4386                 return $this->mNotificationTimestamp[$uid];
4387         }
4388
4389         /**
4390          * Generate strings used for xml 'id' names in monobook tabs
4391          *
4392          * @param $prepend string defaults to 'nstab-'
4393          * @return String XML 'id' name
4394          */
4395         public function getNamespaceKey( $prepend = 'nstab-' ) {
4396                 global $wgContLang;
4397                 // Gets the subject namespace if this title
4398                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4399                 // Checks if cononical namespace name exists for namespace
4400                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4401                         // Uses canonical namespace name
4402                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4403                 } else {
4404                         // Uses text of namespace
4405                         $namespaceKey = $this->getSubjectNsText();
4406                 }
4407                 // Makes namespace key lowercase
4408                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4409                 // Uses main
4410                 if ( $namespaceKey == '' ) {
4411                         $namespaceKey = 'main';
4412                 }
4413                 // Changes file to image for backwards compatibility
4414                 if ( $namespaceKey == 'file' ) {
4415                         $namespaceKey = 'image';
4416                 }
4417                 return $prepend . $namespaceKey;
4418         }
4419
4420         /**
4421          * Get all extant redirects to this Title
4422          *
4423          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4424          * @return Array of Title redirects to this title
4425          */
4426         public function getRedirectsHere( $ns = null ) {
4427                 $redirs = array();
4428
4429                 $dbr = wfGetDB( DB_SLAVE );
4430                 $where = array(
4431                         'rd_namespace' => $this->getNamespace(),
4432                         'rd_title' => $this->getDBkey(),
4433                         'rd_from = page_id'
4434                 );
4435                 if ( $this->isExternal() ) {
4436                         $where['rd_interwiki'] = $this->getInterwiki();
4437                 } else {
4438                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4439                 }
4440                 if ( !is_null( $ns ) ) {
4441                         $where['page_namespace'] = $ns;
4442                 }
4443
4444                 $res = $dbr->select(
4445                         array( 'redirect', 'page' ),
4446                         array( 'page_namespace', 'page_title' ),
4447                         $where,
4448                         __METHOD__
4449                 );
4450
4451                 foreach ( $res as $row ) {
4452                         $redirs[] = self::newFromRow( $row );
4453                 }
4454                 return $redirs;
4455         }
4456
4457         /**
4458          * Check if this Title is a valid redirect target
4459          *
4460          * @return Bool
4461          */
4462         public function isValidRedirectTarget() {
4463                 global $wgInvalidRedirectTargets;
4464
4465                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4466                 if ( $this->isSpecial( 'Userlogout' ) ) {
4467                         return false;
4468                 }
4469
4470                 foreach ( $wgInvalidRedirectTargets as $target ) {
4471                         if ( $this->isSpecial( $target ) ) {
4472                                 return false;
4473                         }
4474                 }
4475
4476                 return true;
4477         }
4478
4479         /**
4480          * Get a backlink cache object
4481          *
4482          * @return BacklinkCache
4483          */
4484         public function getBacklinkCache() {
4485                 return BacklinkCache::get( $this );
4486         }
4487
4488         /**
4489          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4490          *
4491          * @return Boolean
4492          */
4493         public function canUseNoindex() {
4494                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4495
4496                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4497                         ? $wgContentNamespaces
4498                         : $wgExemptFromUserRobotsControl;
4499
4500                 return !in_array( $this->mNamespace, $bannedNamespaces );
4501
4502         }
4503
4504         /**
4505          * Returns the raw sort key to be used for categories, with the specified
4506          * prefix.  This will be fed to Collation::getSortKey() to get a
4507          * binary sortkey that can be used for actual sorting.
4508          *
4509          * @param $prefix string The prefix to be used, specified using
4510          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4511          *   prefix.
4512          * @return string
4513          */
4514         public function getCategorySortkey( $prefix = '' ) {
4515                 $unprefixed = $this->getText();
4516
4517                 // Anything that uses this hook should only depend
4518                 // on the Title object passed in, and should probably
4519                 // tell the users to run updateCollations.php --force
4520                 // in order to re-sort existing category relations.
4521                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4522                 if ( $prefix !== '' ) {
4523                         # Separate with a line feed, so the unprefixed part is only used as
4524                         # a tiebreaker when two pages have the exact same prefix.
4525                         # In UCA, tab is the only character that can sort above LF
4526                         # so we strip both of them from the original prefix.
4527                         $prefix = strtr( $prefix, "\n\t", '  ' );
4528                         return "$prefix\n$unprefixed";
4529                 }
4530                 return $unprefixed;
4531         }
4532
4533         /**
4534          * Get the language in which the content of this page is written in
4535          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4536          * e.g. $wgLang (such as special pages, which are in the user language).
4537          *
4538          * @since 1.18
4539          * @return Language
4540          */
4541         public function getPageLanguage() {
4542                 global $wgLang;
4543                 if ( $this->isSpecialPage() ) {
4544                         // special pages are in the user language
4545                         return $wgLang;
4546                 } elseif ( $this->isCssOrJsPage() || $this->isCssJsSubpage() ) {
4547                         // css/js should always be LTR and is, in fact, English
4548                         return wfGetLangObj( 'en' );
4549                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4550                         // Parse mediawiki messages with correct target language
4551                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4552                         return wfGetLangObj( $lang );
4553                 }
4554                 global $wgContLang;
4555                 // If nothing special, it should be in the wiki content language
4556                 $pageLang = $wgContLang;
4557                 // Hook at the end because we don't want to override the above stuff
4558                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4559                 return wfGetLangObj( $pageLang );
4560         }
4561
4562         /**
4563          * Get the language in which the content of this page is written when
4564          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4565          * e.g. $wgLang (such as special pages, which are in the user language).
4566          *
4567          * @since 1.20
4568          * @return Language
4569          */
4570         public function getPageViewLanguage() {
4571                 $pageLang = $this->getPageLanguage();
4572                 // If this is nothing special (so the content is converted when viewed)
4573                 if ( !$this->isSpecialPage()
4574                         && !$this->isCssOrJsPage() && !$this->isCssJsSubpage()
4575                         && $this->getNamespace() !== NS_MEDIAWIKI
4576                 ) {
4577                         // If the user chooses a variant, the content is actually
4578                         // in a language whose code is the variant code.
4579                         $variant = $pageLang->getPreferredVariant();
4580                         if ( $pageLang->getCode() !== $variant ) {
4581                                 $pageLang = Language::factory( $variant );
4582                         }
4583                 }
4584                 return $pageLang;
4585         }
4586 }