includes/Title.php

   1 <?php
   2 /**
   3  * Representation of 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  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  31  *       and does not rely on global state or the database.
  32  *
  33  * @internal documentation reviewed 15 Mar 2010
  34  */
  35 class Title {
  36         /** @var MapCacheLRU */
  37         static private $titleCache = null;
  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
  65         var $mFragment = '';              // /< Title fragment (i.e. the bit after the #)
  66         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  67         var $mLatestID = false;           // /< ID of most recent revision
  68         var $mContentModel = false;       // /< ID of the page's content model, i.e. one of the CONTENT_MODEL_XXX constants
  69         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  70         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  71         var $mOldRestrictions = false;
  72         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  73         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  74         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  75         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  76         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  77         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  78         var $mPrefixedText = null;        ///< Text form including namespace/interwiki, initialised on demand
  79         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  80         # Don't change the following default, NS_MAIN is hardcoded in several
  81         # places.  See bug 696.
  82         # Zero except in {{transclusion}} tags
  83         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  84         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  85         var $mLength = -1;                // /< The page length, 0 for special pages
  86         var $mRedirect = null;            // /< Is the article at this title a redirect?
  87         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  88         var $mHasSubpage;                 // /< Whether a page has any subpages
  89         private $mPageLanguage = false;   // /< The (string) language code of the page's language and content code.
  90         private $mTitleValue = null;      // /< A corresponding TitleValue object
  91         // @}
  92
  93         /**
  94          * B/C kludge: provide a TitleParser for use by Title.
  95          * Ideally, Title would have no methods that need this.
  96          * Avoid usage of this singleton by using TitleValue
  97          * and the associated services when possible.
  98          *
  99          * @return TitleParser
 100          */
 101         private static function getTitleParser() {
 102                 global $wgContLang, $wgLocalInterwikis;
 103
 104                 static $titleCodec = null;
 105                 static $titleCodecFingerprint = null;
 106
 107                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 108                 // make sure we are using the right one. To detect changes over the course
 109                 // of a request, we remember a fingerprint of the config used to create the
 110                 // codec singleton, and re-create it if the fingerprint doesn't match.
 111                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . join( '+', $wgLocalInterwikis );
 112
 113                 if ( $fingerprint !== $titleCodecFingerprint ) {
 114                         $titleCodec = null;
 115                 }
 116
 117                 if ( !$titleCodec ) {
 118                         $titleCodec = new MediaWikiTitleCodec( $wgContLang, GenderCache::singleton(), $wgLocalInterwikis );
 119                         $titleCodecFingerprint = $fingerprint;
 120                 }
 121
 122                 return $titleCodec;
 123         }
 124
 125         /**
 126          * B/C kludge: provide a TitleParser for use by Title.
 127          * Ideally, Title would have no methods that need this.
 128          * Avoid usage of this singleton by using TitleValue
 129          * and the associated services when possible.
 130          *
 131          * @return TitleFormatter
 132          */
 133         private static function getTitleFormatter() {
 134                 //NOTE: we know that getTitleParser() returns a MediaWikiTitleCodec,
 135                 //      which implements TitleFormatter.
 136                 return self::getTitleParser();
 137         }
 138
 139         /**
 140          * Constructor
 141          */
 142         /*protected*/ function __construct() { }
 143
 144         /**
 145          * Create a new Title from a prefixed DB key
 146          *
 147          * @param string $key The database key, which has underscores
 148          *      instead of spaces, possibly including namespace and
 149          *      interwiki prefixes
 150          * @return Title|null Title, or null on an error
 151          */
 152         public static function newFromDBkey( $key ) {
 153                 $t = new Title();
 154                 $t->mDbkeyform = $key;
 155                 if ( $t->secureAndSplit() ) {
 156                         return $t;
 157                 } else {
 158                         return null;
 159                 }
 160         }
 161
 162         /**
 163          * Create a new Title from a TitleValue
 164          *
 165          * @param TitleValue $titleValue Assumed to be safe.
 166          *
 167          * @return Title
 168          */
 169         public static function newFromTitleValue( TitleValue $titleValue ) {
 170                 return self::makeTitle(
 171                         $titleValue->getNamespace(),
 172                         $titleValue->getText(),
 173                         $titleValue->getFragment() );
 174         }
 175
 176         /**
 177          * Create a new Title from text, such as what one would find in a link. De-
 178          * codes any HTML entities in the text.
 179          *
 180          * @param string $text The link text; spaces, prefixes, and an
 181          *   initial ':' indicating the main namespace are accepted.
 182          * @param int $defaultNamespace The namespace to use if none is specified
 183          *   by a prefix.  If you want to force a specific namespace even if
 184          *   $text might begin with a namespace prefix, use makeTitle() or
 185          *   makeTitleSafe().
 186          * @throws MWException
 187          * @return Title|null Title or null on an error.
 188          */
 189         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 190                 if ( is_object( $text ) ) {
 191                         throw new MWException( 'Title::newFromText given an object' );
 192                 }
 193
 194                 $cache = self::getTitleCache();
 195
 196                 /**
 197                  * Wiki pages often contain multiple links to the same page.
 198                  * Title normalization and parsing can become expensive on
 199                  * pages with many links, so we can save a little time by
 200                  * caching them.
 201                  *
 202                  * In theory these are value objects and won't get changed...
 203                  */
 204                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 205                         return $cache->get( $text );
 206                 }
 207
 208                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 209                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 210
 211                 $t = new Title();
 212                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 213                 $t->mDefaultNamespace = intval( $defaultNamespace );
 214
 215                 if ( $t->secureAndSplit() ) {
 216                         if ( $defaultNamespace == NS_MAIN ) {
 217                                 $cache->set( $text, $t );
 218                         }
 219                         return $t;
 220                 } else {
 221                         $ret = null;
 222                         return $ret;
 223                 }
 224         }
 225
 226         /**
 227          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 228          *
 229          * Example of wrong and broken code:
 230          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 231          *
 232          * Example of right code:
 233          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 234          *
 235          * Create a new Title from URL-encoded text. Ensures that
 236          * the given title's length does not exceed the maximum.
 237          *
 238          * @param string $url The title, as might be taken from a URL
 239          * @return Title|null The new object, or null on an error
 240          */
 241         public static function newFromURL( $url ) {
 242                 $t = new Title();
 243
 244                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 245                 # but some URLs used it as a space replacement and they still come
 246                 # from some external search tools.
 247                 if ( strpos( self::legalChars(), '+' ) === false ) {
 248                         $url = str_replace( '+', ' ', $url );
 249                 }
 250
 251                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 252                 if ( $t->secureAndSplit() ) {
 253                         return $t;
 254                 } else {
 255                         return null;
 256                 }
 257         }
 258
 259         /**
 260          * @return MapCacheLRU
 261          */
 262         private static function getTitleCache() {
 263                 if ( self::$titleCache == null ) {
 264                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 265                 }
 266                 return self::$titleCache;
 267         }
 268
 269         /**
 270          * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 271          * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
 272          *
 273          * @return array
 274          */
 275         protected static function getSelectFields() {
 276                 global $wgContentHandlerUseDB;
 277
 278                 $fields = array(
 279                         'page_namespace', 'page_title', 'page_id',
 280                         'page_len', 'page_is_redirect', 'page_latest',
 281                 );
 282
 283                 if ( $wgContentHandlerUseDB ) {
 284                         $fields[] = 'page_content_model';
 285                 }
 286
 287                 return $fields;
 288         }
 289
 290         /**
 291          * Create a new Title from an article ID
 292          *
 293          * @param int $id The page_id corresponding to the Title to create
 294          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 295          * @return Title|null The new object, or null on an error
 296          */
 297         public static function newFromID( $id, $flags = 0 ) {
 298                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 299                 $row = $db->selectRow(
 300                         'page',
 301                         self::getSelectFields(),
 302                         array( 'page_id' => $id ),
 303                         __METHOD__
 304                 );
 305                 if ( $row !== false ) {
 306                         $title = Title::newFromRow( $row );
 307                 } else {
 308                         $title = null;
 309                 }
 310                 return $title;
 311         }
 312
 313         /**
 314          * Make an array of titles from an array of IDs
 315          *
 316          * @param int[] $ids Array of IDs
 317          * @return Title[] Array of Titles
 318          */
 319         public static function newFromIDs( $ids ) {
 320                 if ( !count( $ids ) ) {
 321                         return array();
 322                 }
 323                 $dbr = wfGetDB( DB_SLAVE );
 324
 325                 $res = $dbr->select(
 326                         'page',
 327                         self::getSelectFields(),
 328                         array( 'page_id' => $ids ),
 329                         __METHOD__
 330                 );
 331
 332                 $titles = array();
 333                 foreach ( $res as $row ) {
 334                         $titles[] = Title::newFromRow( $row );
 335                 }
 336                 return $titles;
 337         }
 338
 339         /**
 340          * Make a Title object from a DB row
 341          *
 342          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 343          * @return Title Corresponding Title
 344          */
 345         public static function newFromRow( $row ) {
 346                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 347                 $t->loadFromRow( $row );
 348                 return $t;
 349         }
 350
 351         /**
 352          * Load Title object fields from a DB row.
 353          * If false is given, the title will be treated as non-existing.
 354          *
 355          * @param stdClass|bool $row Database row
 356          */
 357         public function loadFromRow( $row ) {
 358                 if ( $row ) { // page found
 359                         if ( isset( $row->page_id ) ) {
 360                                 $this->mArticleID = (int)$row->page_id;
 361                         }
 362                         if ( isset( $row->page_len ) ) {
 363                                 $this->mLength = (int)$row->page_len;
 364                         }
 365                         if ( isset( $row->page_is_redirect ) ) {
 366                                 $this->mRedirect = (bool)$row->page_is_redirect;
 367                         }
 368                         if ( isset( $row->page_latest ) ) {
 369                                 $this->mLatestID = (int)$row->page_latest;
 370                         }
 371                         if ( isset( $row->page_content_model ) ) {
 372                                 $this->mContentModel = strval( $row->page_content_model );
 373                         } else {
 374                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 375                         }
 376                 } else { // page not found
 377                         $this->mArticleID = 0;
 378                         $this->mLength = 0;
 379                         $this->mRedirect = false;
 380                         $this->mLatestID = 0;
 381                         $this->mContentModel = false; # initialized lazily in getContentModel()
 382                 }
 383         }
 384
 385         /**
 386          * Create a new Title from a namespace index and a DB key.
 387          * It's assumed that $ns and $title are *valid*, for instance when
 388          * they came directly from the database or a special page name.
 389          * For convenience, spaces are converted to underscores so that
 390          * eg user_text fields can be used directly.
 391          *
 392          * @param int $ns The namespace of the article
 393          * @param string $title The unprefixed database key form
 394          * @param string $fragment The link fragment (after the "#")
 395          * @param string $interwiki The interwiki prefix
 396          * @return Title The new object
 397          */
 398         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 399                 $t = new Title();
 400                 $t->mInterwiki = $interwiki;
 401                 $t->mFragment = $fragment;
 402                 $t->mNamespace = $ns = intval( $ns );
 403                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 404                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 405                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 406                 $t->mTextform = str_replace( '_', ' ', $title );
 407                 $t->mContentModel = false; # initialized lazily in getContentModel()
 408                 return $t;
 409         }
 410
 411         /**
 412          * Create a new Title from a namespace index and a DB key.
 413          * The parameters will be checked for validity, which is a bit slower
 414          * than makeTitle() but safer for user-provided data.
 415          *
 416          * @param int $ns The namespace of the article
 417          * @param string $title Database key form
 418          * @param string $fragment The link fragment (after the "#")
 419          * @param string $interwiki Interwiki prefix
 420          * @return Title The new object, or null on an error
 421          */
 422         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 423                 if ( !MWNamespace::exists( $ns ) ) {
 424                         return null;
 425                 }
 426
 427                 $t = new Title();
 428                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 429                 if ( $t->secureAndSplit() ) {
 430                         return $t;
 431                 } else {
 432                         return null;
 433                 }
 434         }
 435
 436         /**
 437          * Create a new Title for the Main Page
 438          *
 439          * @return Title The new object
 440          */
 441         public static function newMainPage() {
 442                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 443                 // Don't give fatal errors if the message is broken
 444                 if ( !$title ) {
 445                         $title = Title::newFromText( 'Main Page' );
 446                 }
 447                 return $title;
 448         }
 449
 450         /**
 451          * Extract a redirect destination from a string and return the
 452          * Title, or null if the text doesn't contain a valid redirect
 453          * This will only return the very next target, useful for
 454          * the redirect table and other checks that don't need full recursion
 455          *
 456          * @param string $text Text with possible redirect
 457          * @return Title The corresponding Title
 458          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 459          */
 460         public static function newFromRedirect( $text ) {
 461                 ContentHandler::deprecated( __METHOD__, '1.21' );
 462
 463                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 464                 return $content->getRedirectTarget();
 465         }
 466
 467         /**
 468          * Extract a redirect destination from a string and return the
 469          * Title, or null if the text doesn't contain a valid redirect
 470          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 471          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 472          *
 473          * @param string $text Text with possible redirect
 474          * @return Title
 475          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 476          */
 477         public static function newFromRedirectRecurse( $text ) {
 478                 ContentHandler::deprecated( __METHOD__, '1.21' );
 479
 480                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 481                 return $content->getUltimateRedirectTarget();
 482         }
 483
 484         /**
 485          * Extract a redirect destination from a string and return an
 486          * array of Titles, or null if the text doesn't contain a valid redirect
 487          * The last element in the array is the final destination after all redirects
 488          * have been resolved (up to $wgMaxRedirects times)
 489          *
 490          * @param string $text Text with possible redirect
 491          * @return Title[] Array of Titles, with the destination last
 492          * @deprecated since 1.21, use Content::getRedirectChain instead.
 493          */
 494         public static function newFromRedirectArray( $text ) {
 495                 ContentHandler::deprecated( __METHOD__, '1.21' );
 496
 497                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 498                 return $content->getRedirectChain();
 499         }
 500
 501         /**
 502          * Get the prefixed DB key associated with an ID
 503          *
 504          * @param int $id The page_id of the article
 505          * @return Title|null An object representing the article, or null if no such article was found
 506          */
 507         public static function nameOf( $id ) {
 508                 $dbr = wfGetDB( DB_SLAVE );
 509
 510                 $s = $dbr->selectRow(
 511                         'page',
 512                         array( 'page_namespace', 'page_title' ),
 513                         array( 'page_id' => $id ),
 514                         __METHOD__
 515                 );
 516                 if ( $s === false ) {
 517                         return null;
 518                 }
 519
 520                 $n = self::makeName( $s->page_namespace, $s->page_title );
 521                 return $n;
 522         }
 523
 524         /**
 525          * Get a regex character class describing the legal characters in a link
 526          *
 527          * @return string The list of characters, not delimited
 528          */
 529         public static function legalChars() {
 530                 global $wgLegalTitleChars;
 531                 return $wgLegalTitleChars;
 532         }
 533
 534         /**
 535          * Returns a simple regex that will match on characters and sequences invalid in titles.
 536          * Note that this doesn't pick up many things that could be wrong with titles, but that
 537          * replacing this regex with something valid will make many titles valid.
 538          *
 539          * @todo: move this into MediaWikiTitleCodec
 540          *
 541          * @return string Regex string
 542          */
 543         static function getTitleInvalidRegex() {
 544                 static $rxTc = false;
 545                 if ( !$rxTc ) {
 546                         # Matching titles will be held as illegal.
 547                         $rxTc = '/' .
 548                                 # Any character not allowed is forbidden...
 549                                 '[^' . self::legalChars() . ']' .
 550                                 # URL percent encoding sequences interfere with the ability
 551                                 # to round-trip titles -- you can't link to them consistently.
 552                                 '|%[0-9A-Fa-f]{2}' .
 553                                 # XML/HTML character references produce similar issues.
 554                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 555                                 '|&#[0-9]+;' .
 556                                 '|&#x[0-9A-Fa-f]+;' .
 557                                 '/S';
 558                 }
 559
 560                 return $rxTc;
 561         }
 562
 563         /**
 564          * Utility method for converting a character sequence from bytes to Unicode.
 565          *
 566          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 567          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 568          *
 569          * @param string $byteClass
 570          * @return string
 571          */
 572         public static function convertByteClassToUnicodeClass( $byteClass ) {
 573                 $length = strlen( $byteClass );
 574                 // Input token queue
 575                 $x0 = $x1 = $x2 = '';
 576                 // Decoded queue
 577                 $d0 = $d1 = $d2 = '';
 578                 // Decoded integer codepoints
 579                 $ord0 = $ord1 = $ord2 = 0;
 580                 // Re-encoded queue
 581                 $r0 = $r1 = $r2 = '';
 582                 // Output
 583                 $out = '';
 584                 // Flags
 585                 $allowUnicode = false;
 586                 for ( $pos = 0; $pos < $length; $pos++ ) {
 587                         // Shift the queues down
 588                         $x2 = $x1;
 589                         $x1 = $x0;
 590                         $d2 = $d1;
 591                         $d1 = $d0;
 592                         $ord2 = $ord1;
 593                         $ord1 = $ord0;
 594                         $r2 = $r1;
 595                         $r1 = $r0;
 596                         // Load the current input token and decoded values
 597                         $inChar = $byteClass[$pos];
 598                         if ( $inChar == '\\' ) {
 599                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 600                                         $x0 = $inChar . $m[0];
 601                                         $d0 = chr( hexdec( $m[1] ) );
 602                                         $pos += strlen( $m[0] );
 603                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 604                                         $x0 = $inChar . $m[0];
 605                                         $d0 = chr( octdec( $m[0] ) );
 606                                         $pos += strlen( $m[0] );
 607                                 } elseif ( $pos + 1 >= $length ) {
 608                                         $x0 = $d0 = '\\';
 609                                 } else {
 610                                         $d0 = $byteClass[$pos + 1];
 611                                         $x0 = $inChar . $d0;
 612                                         $pos += 1;
 613                                 }
 614                         } else {
 615                                 $x0 = $d0 = $inChar;
 616                         }
 617                         $ord0 = ord( $d0 );
 618                         // Load the current re-encoded value
 619                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 620                                 $r0 = sprintf( '\x%02x', $ord0 );
 621                         } elseif ( $ord0 >= 0x80 ) {
 622                                 // Allow unicode if a single high-bit character appears
 623                                 $r0 = sprintf( '\x%02x', $ord0 );
 624                                 $allowUnicode = true;
 625                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 626                                 $r0 = '\\' . $d0;
 627                         } else {
 628                                 $r0 = $d0;
 629                         }
 630                         // Do the output
 631                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 632                                 // Range
 633                                 if ( $ord2 > $ord0 ) {
 634                                         // Empty range
 635                                 } elseif ( $ord0 >= 0x80 ) {
 636                                         // Unicode range
 637                                         $allowUnicode = true;
 638                                         if ( $ord2 < 0x80 ) {
 639                                                 // Keep the non-unicode section of the range
 640                                                 $out .= "$r2-\\x7F";
 641                                         }
 642                                 } else {
 643                                         // Normal range
 644                                         $out .= "$r2-$r0";
 645                                 }
 646                                 // Reset state to the initial value
 647                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 648                         } elseif ( $ord2 < 0x80 ) {
 649                                 // ASCII character
 650                                 $out .= $r2;
 651                         }
 652                 }
 653                 if ( $ord1 < 0x80 ) {
 654                         $out .= $r1;
 655                 }
 656                 if ( $ord0 < 0x80 ) {
 657                         $out .= $r0;
 658                 }
 659                 if ( $allowUnicode ) {
 660                         $out .= '\u0080-\uFFFF';
 661                 }
 662                 return $out;
 663         }
 664
 665         /**
 666          * Make a prefixed DB key from a DB key and a namespace index
 667          *
 668          * @param int $ns Numerical representation of the namespace
 669          * @param string $title The DB key form the title
 670          * @param string $fragment The link fragment (after the "#")
 671          * @param string $interwiki The interwiki prefix
 672          * @return string The prefixed form of the title
 673          */
 674         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 675                 global $wgContLang;
 676
 677                 $namespace = $wgContLang->getNsText( $ns );
 678                 $name = $namespace == '' ? $title : "$namespace:$title";
 679                 if ( strval( $interwiki ) != '' ) {
 680                         $name = "$interwiki:$name";
 681                 }
 682                 if ( strval( $fragment ) != '' ) {
 683                         $name .= '#' . $fragment;
 684                 }
 685                 return $name;
 686         }
 687
 688         /**
 689          * Escape a text fragment, say from a link, for a URL
 690          *
 691          * @param string $fragment Containing a URL or link fragment (after the "#")
 692          * @return string Escaped string
 693          */
 694         static function escapeFragmentForURL( $fragment ) {
 695                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 696                 # fragments appear not to work in IE (at least up to 7) or in at least
 697                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 698                 # to care if they aren't encoded.
 699                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 700         }
 701
 702         /**
 703          * Callback for usort() to do title sorts by (namespace, title)
 704          *
 705          * @param Title $a
 706          * @param Title $b
 707          *
 708          * @return int Result of string comparison, or namespace comparison
 709          */
 710         public static function compare( $a, $b ) {
 711                 if ( $a->getNamespace() == $b->getNamespace() ) {
 712                         return strcmp( $a->getText(), $b->getText() );
 713                 } else {
 714                         return $a->getNamespace() - $b->getNamespace();
 715                 }
 716         }
 717
 718         /**
 719          * Determine whether the object refers to a page within
 720          * this project.
 721          *
 722          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 723          */
 724         public function isLocal() {
 725                 if ( $this->isExternal() ) {
 726                         $iw = Interwiki::fetch( $this->mInterwiki );
 727                         if ( $iw ) {
 728                                 return $iw->isLocal();
 729                         }
 730                 }
 731                 return true;
 732         }
 733
 734         /**
 735          * Is this Title interwiki?
 736          *
 737          * @return bool
 738          */
 739         public function isExternal() {
 740                 return $this->mInterwiki !== '';
 741         }
 742
 743         /**
 744          * Get the interwiki prefix
 745          *
 746          * Use Title::isExternal to check if a interwiki is set
 747          *
 748          * @return string Interwiki prefix
 749          */
 750         public function getInterwiki() {
 751                 return $this->mInterwiki;
 752         }
 753
 754         /**
 755          * Determine whether the object refers to a page within
 756          * this project and is transcludable.
 757          *
 758          * @return bool True if this is transcludable
 759          */
 760         public function isTrans() {
 761                 if ( !$this->isExternal() ) {
 762                         return false;
 763                 }
 764
 765                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 766         }
 767
 768         /**
 769          * Returns the DB name of the distant wiki which owns the object.
 770          *
 771          * @return string The DB name
 772          */
 773         public function getTransWikiID() {
 774                 if ( !$this->isExternal() ) {
 775                         return false;
 776                 }
 777
 778                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 779         }
 780
 781         /**
 782          * Get a TitleValue object representing this Title.
 783          *
 784          * @note: Not all valid Titles have a corresponding valid TitleValue
 785          * (e.g. TitleValues cannot represent page-local links that have a
 786          * fragment but no title text).
 787          *
 788          * @return TitleValue|null
 789          */
 790         public function getTitleValue() {
 791                 if ( $this->mTitleValue === null ) {
 792                         try {
 793                                 $this->mTitleValue = new TitleValue(
 794                                         $this->getNamespace(),
 795                                         $this->getDBkey(),
 796                                         $this->getFragment() );
 797                         } catch ( InvalidArgumentException $ex ) {
 798                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 799                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 800                         }
 801                 }
 802
 803                 return $this->mTitleValue;
 804         }
 805
 806         /**
 807          * Get the text form (spaces not underscores) of the main part
 808          *
 809          * @return string Main part of the title
 810          */
 811         public function getText() {
 812                 return $this->mTextform;
 813         }
 814
 815         /**
 816          * Get the URL-encoded form of the main part
 817          *
 818          * @return string Main part of the title, URL-encoded
 819          */
 820         public function getPartialURL() {
 821                 return $this->mUrlform;
 822         }
 823
 824         /**
 825          * Get the main part with underscores
 826          *
 827          * @return string Main part of the title, with underscores
 828          */
 829         public function getDBkey() {
 830                 return $this->mDbkeyform;
 831         }
 832
 833         /**
 834          * Get the DB key with the initial letter case as specified by the user
 835          *
 836          * @return string DB key
 837          */
 838         function getUserCaseDBKey() {
 839                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 840                         return $this->mUserCaseDBKey;
 841                 } else {
 842                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 843                         return $this->mDbkeyform;
 844                 }
 845         }
 846
 847         /**
 848          * Get the namespace index, i.e. one of the NS_xxxx constants.
 849          *
 850          * @return int Namespace index
 851          */
 852         public function getNamespace() {
 853                 return $this->mNamespace;
 854         }
 855
 856         /**
 857          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 858          *
 859          * @throws MWException
 860          * @return string Content model id
 861          */
 862         public function getContentModel() {
 863                 if ( !$this->mContentModel ) {
 864                         $linkCache = LinkCache::singleton();
 865                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 866                 }
 867
 868                 if ( !$this->mContentModel ) {
 869                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 870                 }
 871
 872                 if ( !$this->mContentModel ) {
 873                         throw new MWException( 'Failed to determine content model!' );
 874                 }
 875
 876                 return $this->mContentModel;
 877         }
 878
 879         /**
 880          * Convenience method for checking a title's content model name
 881          *
 882          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 883          * @return bool True if $this->getContentModel() == $id
 884          */
 885         public function hasContentModel( $id ) {
 886                 return $this->getContentModel() == $id;
 887         }
 888
 889         /**
 890          * Get the namespace text
 891          *
 892          * @return string Namespace text
 893          */
 894         public function getNsText() {
 895                 if ( $this->isExternal() ) {
 896                         // This probably shouldn't even happen. ohh man, oh yuck.
 897                         // But for interwiki transclusion it sometimes does.
 898                         // Shit. Shit shit shit.
 899                         //
 900                         // Use the canonical namespaces if possible to try to
 901                         // resolve a foreign namespace.
 902                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 903                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 904                         }
 905                 }
 906
 907                 try {
 908                         $formatter = $this->getTitleFormatter();
 909                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 910                 } catch ( InvalidArgumentException $ex )  {
 911                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 912                         return false;
 913                 }
 914         }
 915
 916         /**
 917          * Get the namespace text of the subject (rather than talk) page
 918          *
 919          * @return string Namespace text
 920          */
 921         public function getSubjectNsText() {
 922                 global $wgContLang;
 923                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 924         }
 925
 926         /**
 927          * Get the namespace text of the talk page
 928          *
 929          * @return string Namespace text
 930          */
 931         public function getTalkNsText() {
 932                 global $wgContLang;
 933                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
 934         }
 935
 936         /**
 937          * Could this title have a corresponding talk page?
 938          *
 939          * @return bool
 940          */
 941         public function canTalk() {
 942                 return MWNamespace::canTalk( $this->mNamespace );
 943         }
 944
 945         /**
 946          * Is this in a namespace that allows actual pages?
 947          *
 948          * @return bool
 949          * @internal note -- uses hardcoded namespace index instead of constants
 950          */
 951         public function canExist() {
 952                 return $this->mNamespace >= NS_MAIN;
 953         }
 954
 955         /**
 956          * Can this title be added to a user's watchlist?
 957          *
 958          * @return bool
 959          */
 960         public function isWatchable() {
 961                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 962         }
 963
 964         /**
 965          * Returns true if this is a special page.
 966          *
 967          * @return bool
 968          */
 969         public function isSpecialPage() {
 970                 return $this->getNamespace() == NS_SPECIAL;
 971         }
 972
 973         /**
 974          * Returns true if this title resolves to the named special page
 975          *
 976          * @param string $name The special page name
 977          * @return bool
 978          */
 979         public function isSpecial( $name ) {
 980                 if ( $this->isSpecialPage() ) {
 981                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 982                         if ( $name == $thisName ) {
 983                                 return true;
 984                         }
 985                 }
 986                 return false;
 987         }
 988
 989         /**
 990          * If the Title refers to a special page alias which is not the local default, resolve
 991          * the alias, and localise the name as necessary.  Otherwise, return $this
 992          *
 993          * @return Title
 994          */
 995         public function fixSpecialName() {
 996                 if ( $this->isSpecialPage() ) {
 997                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 998                         if ( $canonicalName ) {
 999                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1000                                 if ( $localName != $this->mDbkeyform ) {
1001                                         return Title::makeTitle( NS_SPECIAL, $localName );
1002                                 }
1003                         }
1004                 }
1005                 return $this;
1006         }
1007
1008         /**
1009          * Returns true if the title is inside the specified namespace.
1010          *
1011          * Please make use of this instead of comparing to getNamespace()
1012          * This function is much more resistant to changes we may make
1013          * to namespaces than code that makes direct comparisons.
1014          * @param int $ns The namespace
1015          * @return bool
1016          * @since 1.19
1017          */
1018         public function inNamespace( $ns ) {
1019                 return MWNamespace::equals( $this->getNamespace(), $ns );
1020         }
1021
1022         /**
1023          * Returns true if the title is inside one of the specified namespaces.
1024          *
1025          * @param ...$namespaces The namespaces to check for
1026          * @return bool
1027          * @since 1.19
1028          */
1029         public function inNamespaces( /* ... */ ) {
1030                 $namespaces = func_get_args();
1031                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1032                         $namespaces = $namespaces[0];
1033                 }
1034
1035                 foreach ( $namespaces as $ns ) {
1036                         if ( $this->inNamespace( $ns ) ) {
1037                                 return true;
1038                         }
1039                 }
1040
1041                 return false;
1042         }
1043
1044         /**
1045          * Returns true if the title has the same subject namespace as the
1046          * namespace specified.
1047          * For example this method will take NS_USER and return true if namespace
1048          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1049          * as their subject namespace.
1050          *
1051          * This is MUCH simpler than individually testing for equivalence
1052          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1053          * @since 1.19
1054          * @param int $ns
1055          * @return bool
1056          */
1057         public function hasSubjectNamespace( $ns ) {
1058                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1059         }
1060
1061         /**
1062          * Is this Title in a namespace which contains content?
1063          * In other words, is this a content page, for the purposes of calculating
1064          * statistics, etc?
1065          *
1066          * @return bool
1067          */
1068         public function isContentPage() {
1069                 return MWNamespace::isContent( $this->getNamespace() );
1070         }
1071
1072         /**
1073          * Would anybody with sufficient privileges be able to move this page?
1074          * Some pages just aren't movable.
1075          *
1076          * @return bool
1077          */
1078         public function isMovable() {
1079                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1080                         // Interwiki title or immovable namespace. Hooks don't get to override here
1081                         return false;
1082                 }
1083
1084                 $result = true;
1085                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1086                 return $result;
1087         }
1088
1089         /**
1090          * Is this the mainpage?
1091          * @note Title::newFromText seems to be sufficiently optimized by the title
1092          * cache that we don't need to over-optimize by doing direct comparisons and
1093          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1094          * ends up reporting something differently than $title->isMainPage();
1095          *
1096          * @since 1.18
1097          * @return bool
1098          */
1099         public function isMainPage() {
1100                 return $this->equals( Title::newMainPage() );
1101         }
1102
1103         /**
1104          * Is this a subpage?
1105          *
1106          * @return bool
1107          */
1108         public function isSubpage() {
1109                 return MWNamespace::hasSubpages( $this->mNamespace )
1110                         ? strpos( $this->getText(), '/' ) !== false
1111                         : false;
1112         }
1113
1114         /**
1115          * Is this a conversion table for the LanguageConverter?
1116          *
1117          * @return bool
1118          */
1119         public function isConversionTable() {
1120                 // @todo ConversionTable should become a separate content model.
1121
1122                 return $this->getNamespace() == NS_MEDIAWIKI &&
1123                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1124         }
1125
1126         /**
1127          * Does that page contain wikitext, or it is JS, CSS or whatever?
1128          *
1129          * @return bool
1130          */
1131         public function isWikitextPage() {
1132                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1133         }
1134
1135         /**
1136          * Could this page contain custom CSS or JavaScript for the global UI.
1137          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1138          * or CONTENT_MODEL_JAVASCRIPT.
1139          *
1140          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
1141          *
1142          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
1143          *
1144          * @return bool
1145          */
1146         public function isCssOrJsPage() {
1147                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1148                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1149                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1150
1151                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
1152                 #      hook functions can force this method to return true even outside the mediawiki namespace.
1153
1154                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
1155
1156                 return $isCssOrJsPage;
1157         }
1158
1159         /**
1160          * Is this a .css or .js subpage of a user page?
1161          * @return bool
1162          */
1163         public function isCssJsSubpage() {
1164                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1165                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1166                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1167         }
1168
1169         /**
1170          * Trim down a .css or .js subpage title to get the corresponding skin name
1171          *
1172          * @return string Containing skin name from .css or .js subpage title
1173          */
1174         public function getSkinFromCssJsSubpage() {
1175                 $subpage = explode( '/', $this->mTextform );
1176                 $subpage = $subpage[count( $subpage ) - 1];
1177                 $lastdot = strrpos( $subpage, '.' );
1178                 if ( $lastdot === false ) {
1179                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1180                 }
1181                 return substr( $subpage, 0, $lastdot );
1182         }
1183
1184         /**
1185          * Is this a .css subpage of a user page?
1186          *
1187          * @return bool
1188          */
1189         public function isCssSubpage() {
1190                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1191                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1192         }
1193
1194         /**
1195          * Is this a .js subpage of a user page?
1196          *
1197          * @return bool
1198          */
1199         public function isJsSubpage() {
1200                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1201                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1202         }
1203
1204         /**
1205          * Is this a talk page of some sort?
1206          *
1207          * @return bool
1208          */
1209         public function isTalkPage() {
1210                 return MWNamespace::isTalk( $this->getNamespace() );
1211         }
1212
1213         /**
1214          * Get a Title object associated with the talk page of this article
1215          *
1216          * @return Title The object for the talk page
1217          */
1218         public function getTalkPage() {
1219                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1220         }
1221
1222         /**
1223          * Get a title object associated with the subject page of this
1224          * talk page
1225          *
1226          * @return Title The object for the subject page
1227          */
1228         public function getSubjectPage() {
1229                 // Is this the same title?
1230                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1231                 if ( $this->getNamespace() == $subjectNS ) {
1232                         return $this;
1233                 }
1234                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1235         }
1236
1237         /**
1238          * Get the default namespace index, for when there is no namespace
1239          *
1240          * @return int Default namespace index
1241          */
1242         public function getDefaultNamespace() {
1243                 return $this->mDefaultNamespace;
1244         }
1245
1246         /**
1247          * Get the Title fragment (i.e.\ the bit after the #) in text form
1248          *
1249          * Use Title::hasFragment to check for a fragment
1250          *
1251          * @return string Title fragment
1252          */
1253         public function getFragment() {
1254                 return $this->mFragment;
1255         }
1256
1257         /**
1258          * Check if a Title fragment is set
1259          *
1260          * @return bool
1261          * @since 1.23
1262          */
1263         public function hasFragment() {
1264                 return $this->mFragment !== '';
1265         }
1266
1267         /**
1268          * Get the fragment in URL form, including the "#" character if there is one
1269          * @return string Fragment in URL form
1270          */
1271         public function getFragmentForURL() {
1272                 if ( !$this->hasFragment() ) {
1273                         return '';
1274                 } else {
1275                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1276                 }
1277         }
1278
1279         /**
1280          * Set the fragment for this title. Removes the first character from the
1281          * specified fragment before setting, so it assumes you're passing it with
1282          * an initial "#".
1283          *
1284          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1285          * Still in active use privately.
1286          *
1287          * @param string $fragment Text
1288          */
1289         public function setFragment( $fragment ) {
1290                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1291         }
1292
1293         /**
1294          * Prefix some arbitrary text with the namespace or interwiki prefix
1295          * of this object
1296          *
1297          * @param string $name The text
1298          * @return string The prefixed text
1299          * @private
1300          */
1301         private function prefix( $name ) {
1302                 $p = '';
1303                 if ( $this->isExternal() ) {
1304                         $p = $this->mInterwiki . ':';
1305                 }
1306
1307                 if ( 0 != $this->mNamespace ) {
1308                         $p .= $this->getNsText() . ':';
1309                 }
1310                 return $p . $name;
1311         }
1312
1313         /**
1314          * Get the prefixed database key form
1315          *
1316          * @return string The prefixed title, with underscores and
1317          *  any interwiki and namespace prefixes
1318          */
1319         public function getPrefixedDBkey() {
1320                 $s = $this->prefix( $this->mDbkeyform );
1321                 $s = str_replace( ' ', '_', $s );
1322                 return $s;
1323         }
1324
1325         /**
1326          * Get the prefixed title with spaces.
1327          * This is the form usually used for display
1328          *
1329          * @return string The prefixed title, with spaces
1330          */
1331         public function getPrefixedText() {
1332                 if ( $this->mPrefixedText === null ) {
1333                         $s = $this->prefix( $this->mTextform );
1334                         $s = str_replace( '_', ' ', $s );
1335                         $this->mPrefixedText = $s;
1336                 }
1337                 return $this->mPrefixedText;
1338         }
1339
1340         /**
1341          * Return a string representation of this title
1342          *
1343          * @return string Representation of this title
1344          */
1345         public function __toString() {
1346                 return $this->getPrefixedText();
1347         }
1348
1349         /**
1350          * Get the prefixed title with spaces, plus any fragment
1351          * (part beginning with '#')
1352          *
1353          * @return string The prefixed title, with spaces and the fragment, including '#'
1354          */
1355         public function getFullText() {
1356                 $text = $this->getPrefixedText();
1357                 if ( $this->hasFragment() ) {
1358                         $text .= '#' . $this->getFragment();
1359                 }
1360                 return $text;
1361         }
1362
1363         /**
1364          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1365          *
1366          * @par Example:
1367          * @code
1368          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1369          * # returns: 'Foo'
1370          * @endcode
1371          *
1372          * @return string Root name
1373          * @since 1.20
1374          */
1375         public function getRootText() {
1376                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1377                         return $this->getText();
1378                 }
1379
1380                 return strtok( $this->getText(), '/' );
1381         }
1382
1383         /**
1384          * Get the root page name title, i.e. the leftmost part before any slashes
1385          *
1386          * @par Example:
1387          * @code
1388          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1389          * # returns: Title{User:Foo}
1390          * @endcode
1391          *
1392          * @return Title Root title
1393          * @since 1.20
1394          */
1395         public function getRootTitle() {
1396                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1397         }
1398
1399         /**
1400          * Get the base page name without a namespace, i.e. the part before the subpage name
1401          *
1402          * @par Example:
1403          * @code
1404          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1405          * # returns: 'Foo/Bar'
1406          * @endcode
1407          *
1408          * @return string Base name
1409          */
1410         public function getBaseText() {
1411                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1412                         return $this->getText();
1413                 }
1414
1415                 $parts = explode( '/', $this->getText() );
1416                 # Don't discard the real title if there's no subpage involved
1417                 if ( count( $parts ) > 1 ) {
1418                         unset( $parts[count( $parts ) - 1] );
1419                 }
1420                 return implode( '/', $parts );
1421         }
1422
1423         /**
1424          * Get the base page name title, i.e. the part before the subpage name
1425          *
1426          * @par Example:
1427          * @code
1428          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1429          * # returns: Title{User:Foo/Bar}
1430          * @endcode
1431          *
1432          * @return Title Base title
1433          * @since 1.20
1434          */
1435         public function getBaseTitle() {
1436                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1437         }
1438
1439         /**
1440          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1441          *
1442          * @par Example:
1443          * @code
1444          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1445          * # returns: "Baz"
1446          * @endcode
1447          *
1448          * @return string Subpage name
1449          */
1450         public function getSubpageText() {
1451                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1452                         return $this->mTextform;
1453                 }
1454                 $parts = explode( '/', $this->mTextform );
1455                 return $parts[count( $parts ) - 1];
1456         }
1457
1458         /**
1459          * Get the title for a subpage of the current page
1460          *
1461          * @par Example:
1462          * @code
1463          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1464          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1465          * @endcode
1466          *
1467          * @param string $text The subpage name to add to the title
1468          * @return Title Subpage title
1469          * @since 1.20
1470          */
1471         public function getSubpage( $text ) {
1472                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1473         }
1474
1475         /**
1476          * Get the HTML-escaped displayable text form.
1477          * Used for the title field in <a> tags.
1478          *
1479          * @return string The text, including any prefixes
1480          * @deprecated since 1.19
1481          */
1482         public function getEscapedText() {
1483                 wfDeprecated( __METHOD__, '1.19' );
1484                 return htmlspecialchars( $this->getPrefixedText() );
1485         }
1486
1487         /**
1488          * Get a URL-encoded form of the subpage text
1489          *
1490          * @return string URL-encoded subpage name
1491          */
1492         public function getSubpageUrlForm() {
1493                 $text = $this->getSubpageText();
1494                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1495                 return $text;
1496         }
1497
1498         /**
1499          * Get a URL-encoded title (not an actual URL) including interwiki
1500          *
1501          * @return string The URL-encoded form
1502          */
1503         public function getPrefixedURL() {
1504                 $s = $this->prefix( $this->mDbkeyform );
1505                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1506                 return $s;
1507         }
1508
1509         /**
1510          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1511          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1512          * second argument named variant. This was deprecated in favor
1513          * of passing an array of option with a "variant" key
1514          * Once $query2 is removed for good, this helper can be dropped
1515          * and the wfArrayToCgi moved to getLocalURL();
1516          *
1517          * @since 1.19 (r105919)
1518          * @param array|string $query
1519          * @param bool $query2
1520          * @return string
1521          */
1522         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1523                 if ( $query2 !== false ) {
1524                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1525                                 "method called with a second parameter is deprecated. Add your " .
1526                                 "parameter to an array passed as the first parameter.", "1.19" );
1527                 }
1528                 if ( is_array( $query ) ) {
1529                         $query = wfArrayToCgi( $query );
1530                 }
1531                 if ( $query2 ) {
1532                         if ( is_string( $query2 ) ) {
1533                                 // $query2 is a string, we will consider this to be
1534                                 // a deprecated $variant argument and add it to the query
1535                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1536                         } else {
1537                                 $query2 = wfArrayToCgi( $query2 );
1538                         }
1539                         // If we have $query content add a & to it first
1540                         if ( $query ) {
1541                                 $query .= '&';
1542                         }
1543                         // Now append the queries together
1544                         $query .= $query2;
1545                 }
1546                 return $query;
1547         }
1548
1549         /**
1550          * Get a real URL referring to this title, with interwiki link and
1551          * fragment
1552          *
1553          * @see self::getLocalURL for the arguments.
1554          * @see wfExpandUrl
1555          * @param array|string $query
1556          * @param bool $query2
1557          * @param string $proto Protocol type to use in URL
1558          * @return string The URL
1559          */
1560         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1561                 $query = self::fixUrlQueryArgs( $query, $query2 );
1562
1563                 # Hand off all the decisions on urls to getLocalURL
1564                 $url = $this->getLocalURL( $query );
1565
1566                 # Expand the url to make it a full url. Note that getLocalURL has the
1567                 # potential to output full urls for a variety of reasons, so we use
1568                 # wfExpandUrl instead of simply prepending $wgServer
1569                 $url = wfExpandUrl( $url, $proto );
1570
1571                 # Finally, add the fragment.
1572                 $url .= $this->getFragmentForURL();
1573
1574                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1575                 return $url;
1576         }
1577
1578         /**
1579          * Get a URL with no fragment or server name (relative URL) from a Title object.
1580          * If this page is generated with action=render, however,
1581          * $wgServer is prepended to make an absolute URL.
1582          *
1583          * @see self::getFullURL to always get an absolute URL.
1584          * @see self::newFromText to produce a Title object.
1585          *
1586          * @param string|array $query an optional query string,
1587          *   not used for interwiki links. Can be specified as an associative array as well,
1588          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1589          *   Some query patterns will trigger various shorturl path replacements.
1590          * @param array $query2 An optional secondary query array. This one MUST
1591          *   be an array. If a string is passed it will be interpreted as a deprecated
1592          *   variant argument and urlencoded into a variant= argument.
1593          *   This second query argument will be added to the $query
1594          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1595          *   pair in the first parameter array instead.
1596          *
1597          * @return string String of the URL.
1598          */
1599         public function getLocalURL( $query = '', $query2 = false ) {
1600                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1601
1602                 $query = self::fixUrlQueryArgs( $query, $query2 );
1603
1604                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1605                 if ( $interwiki ) {
1606                         $namespace = $this->getNsText();
1607                         if ( $namespace != '' ) {
1608                                 # Can this actually happen? Interwikis shouldn't be parsed.
1609                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1610                                 $namespace .= ':';
1611                         }
1612                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1613                         $url = wfAppendQuery( $url, $query );
1614                 } else {
1615                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1616                         if ( $query == '' ) {
1617                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1618                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1619                         } else {
1620                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1621                                 $url = false;
1622                                 $matches = array();
1623
1624                                 if ( !empty( $wgActionPaths )
1625                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1626                                 ) {
1627                                         $action = urldecode( $matches[2] );
1628                                         if ( isset( $wgActionPaths[$action] ) ) {
1629                                                 $query = $matches[1];
1630                                                 if ( isset( $matches[4] ) ) {
1631                                                         $query .= $matches[4];
1632                                                 }
1633                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1634                                                 if ( $query != '' ) {
1635                                                         $url = wfAppendQuery( $url, $query );
1636                                                 }
1637                                         }
1638                                 }
1639
1640                                 if ( $url === false
1641                                         && $wgVariantArticlePath
1642                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1643                                         && $this->getPageLanguage()->hasVariants()
1644                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1645                                 ) {
1646                                         $variant = urldecode( $matches[1] );
1647                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1648                                                 // Only do the variant replacement if the given variant is a valid
1649                                                 // variant for the page's language.
1650                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1651                                                 $url = str_replace( '$1', $dbkey, $url );
1652                                         }
1653                                 }
1654
1655                                 if ( $url === false ) {
1656                                         if ( $query == '-' ) {
1657                                                 $query = '';
1658                                         }
1659                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1660                                 }
1661                         }
1662
1663                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1664
1665                         // @todo FIXME: This causes breakage in various places when we
1666                         // actually expected a local URL and end up with dupe prefixes.
1667                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1668                                 $url = $wgServer . $url;
1669                         }
1670                 }
1671                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1672                 return $url;
1673         }
1674
1675         /**
1676          * Get a URL that's the simplest URL that will be valid to link, locally,
1677          * to the current Title.  It includes the fragment, but does not include
1678          * the server unless action=render is used (or the link is external).  If
1679          * there's a fragment but the prefixed text is empty, we just return a link
1680          * to the fragment.
1681          *
1682          * The result obviously should not be URL-escaped, but does need to be
1683          * HTML-escaped if it's being output in HTML.
1684          *
1685          * @param array $query
1686          * @param bool $query2
1687          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1688          * @see self::getLocalURL for the arguments.
1689          * @return string The URL
1690          */
1691         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1692                 wfProfileIn( __METHOD__ );
1693                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1694                         $ret = $this->getFullURL( $query, $query2, $proto );
1695                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1696                         $ret = $this->getFragmentForURL();
1697                 } else {
1698                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1699                 }
1700                 wfProfileOut( __METHOD__ );
1701                 return $ret;
1702         }
1703
1704         /**
1705          * Get an HTML-escaped version of the URL form, suitable for
1706          * using in a link, without a server name or fragment
1707          *
1708          * @see self::getLocalURL for the arguments.
1709          * @param string $query
1710          * @param bool|string $query2
1711          * @return string The URL
1712          * @deprecated since 1.19
1713          */
1714         public function escapeLocalURL( $query = '', $query2 = false ) {
1715                 wfDeprecated( __METHOD__, '1.19' );
1716                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1717         }
1718
1719         /**
1720          * Get an HTML-escaped version of the URL form, suitable for
1721          * using in a link, including the server name and fragment
1722          *
1723          * @see self::getLocalURL for the arguments.
1724          * @return string The URL
1725          * @deprecated since 1.19
1726          */
1727         public function escapeFullURL( $query = '', $query2 = false ) {
1728                 wfDeprecated( __METHOD__, '1.19' );
1729                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1730         }
1731
1732         /**
1733          * Get the URL form for an internal link.
1734          * - Used in various Squid-related code, in case we have a different
1735          * internal hostname for the server from the exposed one.
1736          *
1737          * This uses $wgInternalServer to qualify the path, or $wgServer
1738          * if $wgInternalServer is not set. If the server variable used is
1739          * protocol-relative, the URL will be expanded to http://
1740          *
1741          * @see self::getLocalURL for the arguments.
1742          * @return string The URL
1743          */
1744         public function getInternalURL( $query = '', $query2 = false ) {
1745                 global $wgInternalServer, $wgServer;
1746                 $query = self::fixUrlQueryArgs( $query, $query2 );
1747                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1748                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1749                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1750                 return $url;
1751         }
1752
1753         /**
1754          * Get the URL for a canonical link, for use in things like IRC and
1755          * e-mail notifications. Uses $wgCanonicalServer and the
1756          * GetCanonicalURL hook.
1757          *
1758          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1759          *
1760          * @see self::getLocalURL for the arguments.
1761          * @return string The URL
1762          * @since 1.18
1763          */
1764         public function getCanonicalURL( $query = '', $query2 = false ) {
1765                 $query = self::fixUrlQueryArgs( $query, $query2 );
1766                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1767                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1768                 return $url;
1769         }
1770
1771         /**
1772          * HTML-escaped version of getCanonicalURL()
1773          *
1774          * @see self::getLocalURL for the arguments.
1775          * @since 1.18
1776          * @return string
1777          * @deprecated since 1.19
1778          */
1779         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1780                 wfDeprecated( __METHOD__, '1.19' );
1781                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1782         }
1783
1784         /**
1785          * Get the edit URL for this Title
1786          *
1787          * @return string The URL, or a null string if this is an interwiki link
1788          */
1789         public function getEditURL() {
1790                 if ( $this->isExternal() ) {
1791                         return '';
1792                 }
1793                 $s = $this->getLocalURL( 'action=edit' );
1794
1795                 return $s;
1796         }
1797
1798         /**
1799          * Is $wgUser watching this page?
1800          *
1801          * @deprecated since 1.20; use User::isWatched() instead.
1802          * @return bool
1803          */
1804         public function userIsWatching() {
1805                 global $wgUser;
1806
1807                 if ( is_null( $this->mWatched ) ) {
1808                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1809                                 $this->mWatched = false;
1810                         } else {
1811                                 $this->mWatched = $wgUser->isWatched( $this );
1812                         }
1813                 }
1814                 return $this->mWatched;
1815         }
1816
1817         /**
1818          * Can $wgUser read this page?
1819          *
1820          * @deprecated since 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1821          * @return bool
1822          */
1823         public function userCanRead() {
1824                 wfDeprecated( __METHOD__, '1.19' );
1825                 return $this->userCan( 'read' );
1826         }
1827
1828         /**
1829          * Can $user perform $action on this page?
1830          * This skips potentially expensive cascading permission checks
1831          * as well as avoids expensive error formatting
1832          *
1833          * Suitable for use for nonessential UI controls in common cases, but
1834          * _not_ for functional access control.
1835          *
1836          * May provide false positives, but should never provide a false negative.
1837          *
1838          * @param string $action Action that permission needs to be checked for
1839          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1840          * @return bool
1841          */
1842         public function quickUserCan( $action, $user = null ) {
1843                 return $this->userCan( $action, $user, false );
1844         }
1845
1846         /**
1847          * Can $user perform $action on this page?
1848          *
1849          * @param string $action Action that permission needs to be checked for
1850          * @param User $user User to check (since 1.19); $wgUser will be used if not
1851          *   provided.
1852          * @param bool $doExpensiveQueries Set this to false to avoid doing
1853          *   unnecessary queries.
1854          * @return bool
1855          */
1856         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1857                 if ( !$user instanceof User ) {
1858                         global $wgUser;
1859                         $user = $wgUser;
1860                 }
1861                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1862         }
1863
1864         /**
1865          * Can $user perform $action on this page?
1866          *
1867          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1868          *
1869          * @param string $action action that permission needs to be checked for
1870          * @param User $user User to check
1871          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1872          *   queries by skipping checks for cascading protections and user blocks.
1873          * @param array $ignoreErrors of Strings Set this to a list of message keys
1874          *   whose corresponding errors may be ignored.
1875          * @return array Array of arguments to wfMessage to explain permissions problems.
1876          */
1877         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1878                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1879
1880                 // Remove the errors being ignored.
1881                 foreach ( $errors as $index => $error ) {
1882                         $error_key = is_array( $error ) ? $error[0] : $error;
1883
1884                         if ( in_array( $error_key, $ignoreErrors ) ) {
1885                                 unset( $errors[$index] );
1886                         }
1887                 }
1888
1889                 return $errors;
1890         }
1891
1892         /**
1893          * Permissions checks that fail most often, and which are easiest to test.
1894          *
1895          * @param string $action the action to check
1896          * @param User $user User to check
1897          * @param array $errors List of current errors
1898          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
1899          * @param bool $short Short circuit on first error
1900          *
1901          * @return array List of errors
1902          */
1903         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1904                 if ( !wfRunHooks( 'TitleQuickPermissions', array( $this, $user, $action, &$errors, $doExpensiveQueries, $short ) ) ) {
1905                         return $errors;
1906                 }
1907
1908                 if ( $action == 'create' ) {
1909                         if (
1910                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1911                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1912                         ) {
1913                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1914                         }
1915                 } elseif ( $action == 'move' ) {
1916                         if ( !$user->isAllowed( 'move-rootuserpages' )
1917                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1918                                 // Show user page-specific message only if the user can move other pages
1919                                 $errors[] = array( 'cant-move-user-page' );
1920                         }
1921
1922                         // Check if user is allowed to move files if it's a file
1923                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1924                                 $errors[] = array( 'movenotallowedfile' );
1925                         }
1926
1927                         // Check if user is allowed to move category pages if it's a category page
1928                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1929                                 $errors[] = array( 'cant-move-category-page' );
1930                         }
1931
1932                         if ( !$user->isAllowed( 'move' ) ) {
1933                                 // User can't move anything
1934                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1935                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1936                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1937                                         // custom message if logged-in users without any special rights can move
1938                                         $errors[] = array( 'movenologintext' );
1939                                 } else {
1940                                         $errors[] = array( 'movenotallowed' );
1941                                 }
1942                         }
1943                 } elseif ( $action == 'move-target' ) {
1944                         if ( !$user->isAllowed( 'move' ) ) {
1945                                 // User can't move anything
1946                                 $errors[] = array( 'movenotallowed' );
1947                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1948                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1949                                 // Show user page-specific message only if the user can move other pages
1950                                 $errors[] = array( 'cant-move-to-user-page' );
1951                         } elseif ( !$user->isAllowed( 'move-categorypages' )
1952                                         && $this->mNamespace == NS_CATEGORY ) {
1953                                 // Show user page-specific message only if the user can move other pages
1954                                 $errors[] = array( 'cant-move-to-category-page' );
1955                         }
1956                 } elseif ( !$user->isAllowed( $action ) ) {
1957                         $errors[] = $this->missingPermissionError( $action, $short );
1958                 }
1959
1960                 return $errors;
1961         }
1962
1963         /**
1964          * Add the resulting error code to the errors array
1965          *
1966          * @param array $errors List of current errors
1967          * @param array $result Result of errors
1968          *
1969          * @return array List of errors
1970          */
1971         private function resultToError( $errors, $result ) {
1972                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1973                         // A single array representing an error
1974                         $errors[] = $result;
1975                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1976                         // A nested array representing multiple errors
1977                         $errors = array_merge( $errors, $result );
1978                 } elseif ( $result !== '' && is_string( $result ) ) {
1979                         // A string representing a message-id
1980                         $errors[] = array( $result );
1981                 } elseif ( $result === false ) {
1982                         // a generic "We don't want them to do that"
1983                         $errors[] = array( 'badaccess-group0' );
1984                 }
1985                 return $errors;
1986         }
1987
1988         /**
1989          * Check various permission hooks
1990          *
1991          * @param string $action The action to check
1992          * @param User $user User to check
1993          * @param array $errors List of current errors
1994          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
1995          * @param bool $short Short circuit on first error
1996          *
1997          * @return array List of errors
1998          */
1999         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
2000                 // Use getUserPermissionsErrors instead
2001                 $result = '';
2002                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2003                         return $result ? array() : array( array( 'badaccess-group0' ) );
2004                 }
2005                 // Check getUserPermissionsErrors hook
2006                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2007                         $errors = $this->resultToError( $errors, $result );
2008                 }
2009                 // Check getUserPermissionsErrorsExpensive hook
2010                 if (
2011                         $doExpensiveQueries
2012                         && !( $short && count( $errors ) > 0 )
2013                         && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2014                 ) {
2015                         $errors = $this->resultToError( $errors, $result );
2016                 }
2017
2018                 return $errors;
2019         }
2020
2021         /**
2022          * Check permissions on special pages & namespaces
2023          *
2024          * @param string $action The action to check
2025          * @param User $user User to check
2026          * @param array $errors List of current errors
2027          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2028          * @param bool $short Short circuit on first error
2029          *
2030          * @return array List of errors
2031          */
2032         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2033                 # Only 'createaccount' can be performed on special pages,
2034                 # which don't actually exist in the DB.
2035                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2036                         $errors[] = array( 'ns-specialprotected' );
2037                 }
2038
2039                 # Check $wgNamespaceProtection for restricted namespaces
2040                 if ( $this->isNamespaceProtected( $user ) ) {
2041                         $ns = $this->mNamespace == NS_MAIN ?
2042                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2043                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2044                                 array( 'protectedinterface' ) : array( 'namespaceprotected', $ns );
2045                 }
2046
2047                 return $errors;
2048         }
2049
2050         /**
2051          * Check CSS/JS sub-page permissions
2052          *
2053          * @param string $action The action to check
2054          * @param User $user User to check
2055          * @param array $errors List of current errors
2056          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2057          * @param bool $short Short circuit on first error
2058          *
2059          * @return array List of errors
2060          */
2061         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2062                 # Protect css/js subpages of user pages
2063                 # XXX: this might be better using restrictions
2064                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2065                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2066                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2067                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2068                                         $errors[] = array( 'mycustomcssprotected' );
2069                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2070                                         $errors[] = array( 'mycustomjsprotected' );
2071                                 }
2072                         } else {
2073                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2074                                         $errors[] = array( 'customcssprotected' );
2075                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2076                                         $errors[] = array( 'customjsprotected' );
2077                                 }
2078                         }
2079                 }
2080
2081                 return $errors;
2082         }
2083
2084         /**
2085          * Check against page_restrictions table requirements on this
2086          * page. The user must possess all required rights for this
2087          * action.
2088          *
2089          * @param string $action The action to check
2090          * @param User $user User to check
2091          * @param array $errors List of current errors
2092          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2093          * @param bool $short Short circuit on first error
2094          *
2095          * @return array List of errors
2096          */
2097         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2098                 foreach ( $this->getRestrictions( $action ) as $right ) {
2099                         // Backwards compatibility, rewrite sysop -> editprotected
2100                         if ( $right == 'sysop' ) {
2101                                 $right = 'editprotected';
2102                         }
2103                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2104                         if ( $right == 'autoconfirmed' ) {
2105                                 $right = 'editsemiprotected';
2106                         }
2107                         if ( $right == '' ) {
2108                                 continue;
2109                         }
2110                         if ( !$user->isAllowed( $right ) ) {
2111                                 $errors[] = array( 'protectedpagetext', $right );
2112                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2113                                 $errors[] = array( 'protectedpagetext', 'protect' );
2114                         }
2115                 }
2116
2117                 return $errors;
2118         }
2119
2120         /**
2121          * Check restrictions on cascading pages.
2122          *
2123          * @param string $action The action to check
2124          * @param User $user User to check
2125          * @param array $errors List of current errors
2126          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2127          * @param bool $short Short circuit on first error
2128          *
2129          * @return array List of errors
2130          */
2131         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2132                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
2133                         # We /could/ use the protection level on the source page, but it's
2134                         # fairly ugly as we have to establish a precedence hierarchy for pages
2135                         # included by multiple cascade-protected pages. So just restrict
2136                         # it to people with 'protect' permission, as they could remove the
2137                         # protection anyway.
2138                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2139                         # Cascading protection depends on more than this page...
2140                         # Several cascading protected pages may include this page...
2141                         # Check each cascading level
2142                         # This is only for protection restrictions, not for all actions
2143                         if ( isset( $restrictions[$action] ) ) {
2144                                 foreach ( $restrictions[$action] as $right ) {
2145                                         // Backwards compatibility, rewrite sysop -> editprotected
2146                                         if ( $right == 'sysop' ) {
2147                                                 $right = 'editprotected';
2148                                         }
2149                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2150                                         if ( $right == 'autoconfirmed' ) {
2151                                                 $right = 'editsemiprotected';
2152                                         }
2153                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2154                                                 $pages = '';
2155                                                 foreach ( $cascadingSources as $page ) {
2156                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2157                                                 }
2158                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
2159                                         }
2160                                 }
2161                         }
2162                 }
2163
2164                 return $errors;
2165         }
2166
2167         /**
2168          * Check action permissions not already checked in checkQuickPermissions
2169          *
2170          * @param string $action The action to check
2171          * @param User $user User to check
2172          * @param array $errors List of current errors
2173          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2174          * @param bool $short Short circuit on first error
2175          *
2176          * @return array List of errors
2177          */
2178         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2179                 global $wgDeleteRevisionsLimit, $wgLang;
2180
2181                 if ( $action == 'protect' ) {
2182                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
2183                                 // If they can't edit, they shouldn't protect.
2184                                 $errors[] = array( 'protect-cantedit' );
2185                         }
2186                 } elseif ( $action == 'create' ) {
2187                         $title_protection = $this->getTitleProtection();
2188                         if ( $title_protection ) {
2189                                 if ( $title_protection['pt_create_perm'] == 'sysop' ) {
2190                                         $title_protection['pt_create_perm'] = 'editprotected'; // B/C
2191                                 }
2192                                 if ( $title_protection['pt_create_perm'] == 'autoconfirmed' ) {
2193                                         $title_protection['pt_create_perm'] = 'editsemiprotected'; // B/C
2194                                 }
2195                                 if ( $title_protection['pt_create_perm'] == ''
2196                                         || !$user->isAllowed( $title_protection['pt_create_perm'] )
2197                                 ) {
2198                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
2199                                 }
2200                         }
2201                 } elseif ( $action == 'move' ) {
2202                         // Check for immobile pages
2203                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2204                                 // Specific message for this case
2205                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2206                         } elseif ( !$this->isMovable() ) {
2207                                 // Less specific message for rarer cases
2208                                 $errors[] = array( 'immobile-source-page' );
2209                         }
2210                 } elseif ( $action == 'move-target' ) {
2211                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2212                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2213                         } elseif ( !$this->isMovable() ) {
2214                                 $errors[] = array( 'immobile-target-page' );
2215                         }
2216                 } elseif ( $action == 'delete' ) {
2217                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2218                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2219                         ) {
2220                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2221                         }
2222                 }
2223                 return $errors;
2224         }
2225
2226         /**
2227          * Check that the user isn't blocked from editing.
2228          *
2229          * @param string $action The action to check
2230          * @param User $user User to check
2231          * @param array $errors List of current errors
2232          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2233          * @param bool $short Short circuit on first error
2234          *
2235          * @return array List of errors
2236          */
2237         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2238                 // Account creation blocks handled at userlogin.
2239                 // Unblocking handled in SpecialUnblock
2240                 if ( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2241                         return $errors;
2242                 }
2243
2244                 global $wgEmailConfirmToEdit;
2245
2246                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2247                         $errors[] = array( 'confirmedittext' );
2248                 }
2249
2250                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2251                         // Don't block the user from editing their own talk page unless they've been
2252                         // explicitly blocked from that too.
2253                 } elseif ( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2254                         // @todo FIXME: Pass the relevant context into this function.
2255                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2256                 }
2257
2258                 return $errors;
2259         }
2260
2261         /**
2262          * Check that the user is allowed to read this page.
2263          *
2264          * @param string $action The action to check
2265          * @param User $user User to check
2266          * @param array $errors List of current errors
2267          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2268          * @param bool $short Short circuit on first error
2269          *
2270          * @return array List of errors
2271          */
2272         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2273                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2274
2275                 $whitelisted = false;
2276                 if ( User::isEveryoneAllowed( 'read' ) ) {
2277                         # Shortcut for public wikis, allows skipping quite a bit of code
2278                         $whitelisted = true;
2279                 } elseif ( $user->isAllowed( 'read' ) ) {
2280                         # If the user is allowed to read pages, he is allowed to read all pages
2281                         $whitelisted = true;
2282                 } elseif ( $this->isSpecial( 'Userlogin' )
2283                         || $this->isSpecial( 'ChangePassword' )
2284                         || $this->isSpecial( 'PasswordReset' )
2285                 ) {
2286                         # Always grant access to the login page.
2287                         # Even anons need to be able to log in.
2288                         $whitelisted = true;
2289                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2290                         # Time to check the whitelist
2291                         # Only do these checks is there's something to check against
2292                         $name = $this->getPrefixedText();
2293                         $dbName = $this->getPrefixedDBkey();
2294
2295                         // Check for explicit whitelisting with and without underscores
2296                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2297                                 $whitelisted = true;
2298                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2299                                 # Old settings might have the title prefixed with
2300                                 # a colon for main-namespace pages
2301                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2302                                         $whitelisted = true;
2303                                 }
2304                         } elseif ( $this->isSpecialPage() ) {
2305                                 # If it's a special page, ditch the subpage bit and check again
2306                                 $name = $this->getDBkey();
2307                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2308                                 if ( $name ) {
2309                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2310                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2311                                                 $whitelisted = true;
2312                                         }
2313                                 }
2314                         }
2315                 }
2316
2317                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2318                         $name = $this->getPrefixedText();
2319                         // Check for regex whitelisting
2320                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2321                                 if ( preg_match( $listItem, $name ) ) {
2322                                         $whitelisted = true;
2323                                         break;
2324                                 }
2325                         }
2326                 }
2327
2328                 if ( !$whitelisted ) {
2329                         # If the title is not whitelisted, give extensions a chance to do so...
2330                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2331                         if ( !$whitelisted ) {
2332                                 $errors[] = $this->missingPermissionError( $action, $short );
2333                         }
2334                 }
2335
2336                 return $errors;
2337         }
2338
2339         /**
2340          * Get a description array when the user doesn't have the right to perform
2341          * $action (i.e. when User::isAllowed() returns false)
2342          *
2343          * @param string $action The action to check
2344          * @param bool $short Short circuit on first error
2345          * @return array List of errors
2346          */
2347         private function missingPermissionError( $action, $short ) {
2348                 // We avoid expensive display logic for quickUserCan's and such
2349                 if ( $short ) {
2350                         return array( 'badaccess-group0' );
2351                 }
2352
2353                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2354                         User::getGroupsWithPermission( $action ) );
2355
2356                 if ( count( $groups ) ) {
2357                         global $wgLang;
2358                         return array(
2359                                 'badaccess-groups',
2360                                 $wgLang->commaList( $groups ),
2361                                 count( $groups )
2362                         );
2363                 } else {
2364                         return array( 'badaccess-group0' );
2365                 }
2366         }
2367
2368         /**
2369          * Can $user perform $action on this page? This is an internal function,
2370          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2371          * checks on wfReadOnly() and blocks)
2372          *
2373          * @param string $action Action that permission needs to be checked for
2374          * @param User $user User to check
2375          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
2376          * @param bool $short Set this to true to stop after the first permission error.
2377          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2378          */
2379         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2380                 wfProfileIn( __METHOD__ );
2381
2382                 # Read has special handling
2383                 if ( $action == 'read' ) {
2384                         $checks = array(
2385                                 'checkPermissionHooks',
2386                                 'checkReadPermissions',
2387                         );
2388                 } else {
2389                         $checks = array(
2390                                 'checkQuickPermissions',
2391                                 'checkPermissionHooks',
2392                                 'checkSpecialsAndNSPermissions',
2393                                 'checkCSSandJSPermissions',
2394                                 'checkPageRestrictions',
2395                                 'checkCascadingSourcesRestrictions',
2396                                 'checkActionPermissions',
2397                                 'checkUserBlock'
2398                         );
2399                 }
2400
2401                 $errors = array();
2402                 while ( count( $checks ) > 0 &&
2403                                 !( $short && count( $errors ) > 0 ) ) {
2404                         $method = array_shift( $checks );
2405                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2406                 }
2407
2408                 wfProfileOut( __METHOD__ );
2409                 return $errors;
2410         }
2411
2412         /**
2413          * Get a filtered list of all restriction types supported by this wiki.
2414          * @param bool $exists True to get all restriction types that apply to
2415          * titles that do exist, False for all restriction types that apply to
2416          * titles that do not exist
2417          * @return array
2418          */
2419         public static function getFilteredRestrictionTypes( $exists = true ) {
2420                 global $wgRestrictionTypes;
2421                 $types = $wgRestrictionTypes;
2422                 if ( $exists ) {
2423                         # Remove the create restriction for existing titles
2424                         $types = array_diff( $types, array( 'create' ) );
2425                 } else {
2426                         # Only the create and upload restrictions apply to non-existing titles
2427                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2428                 }
2429                 return $types;
2430         }
2431
2432         /**
2433          * Returns restriction types for the current Title
2434          *
2435          * @return array Applicable restriction types
2436          */
2437         public function getRestrictionTypes() {
2438                 if ( $this->isSpecialPage() ) {
2439                         return array();
2440                 }
2441
2442                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2443
2444                 if ( $this->getNamespace() != NS_FILE ) {
2445                         # Remove the upload restriction for non-file titles
2446                         $types = array_diff( $types, array( 'upload' ) );
2447                 }
2448
2449                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2450
2451                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2452                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2453
2454                 return $types;
2455         }
2456
2457         /**
2458          * Is this title subject to title protection?
2459          * Title protection is the one applied against creation of such title.
2460          *
2461          * @return array|bool An associative array representing any existent title
2462          *   protection, or false if there's none.
2463          */
2464         private function getTitleProtection() {
2465                 // Can't protect pages in special namespaces
2466                 if ( $this->getNamespace() < 0 ) {
2467                         return false;
2468                 }
2469
2470                 // Can't protect pages that exist.
2471                 if ( $this->exists() ) {
2472                         return false;
2473                 }
2474
2475                 if ( !isset( $this->mTitleProtection ) ) {
2476                         $dbr = wfGetDB( DB_SLAVE );
2477                         $res = $dbr->select(
2478                                 'protected_titles',
2479                                 array( 'pt_user', 'pt_reason', 'pt_expiry', 'pt_create_perm' ),
2480                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2481                                 __METHOD__
2482                         );
2483
2484                         // fetchRow returns false if there are no rows.
2485                         $this->mTitleProtection = $dbr->fetchRow( $res );
2486                 }
2487                 return $this->mTitleProtection;
2488         }
2489
2490         /**
2491          * Update the title protection status
2492          *
2493          * @deprecated since 1.19; use WikiPage::doUpdateRestrictions() instead.
2494          * @param string $create_perm Permission required for creation
2495          * @param string $reason Reason for protection
2496          * @param string $expiry Expiry timestamp
2497          * @return bool
2498          */
2499         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2500                 wfDeprecated( __METHOD__, '1.19' );
2501
2502                 global $wgUser;
2503
2504                 $limit = array( 'create' => $create_perm );
2505                 $expiry = array( 'create' => $expiry );
2506
2507                 $page = WikiPage::factory( $this );
2508                 $cascade = false;
2509                 $status = $page->doUpdateRestrictions( $limit, $expiry, $cascade, $reason, $wgUser );
2510
2511                 return $status->isOK();
2512         }
2513
2514         /**
2515          * Remove any title protection due to page existing
2516          */
2517         public function deleteTitleProtection() {
2518                 $dbw = wfGetDB( DB_MASTER );
2519
2520                 $dbw->delete(
2521                         'protected_titles',
2522                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2523                         __METHOD__
2524                 );
2525                 $this->mTitleProtection = false;
2526         }
2527
2528         /**
2529          * Is this page "semi-protected" - the *only* protection levels are listed
2530          * in $wgSemiprotectedRestrictionLevels?
2531          *
2532          * @param string $action Action to check (default: edit)
2533          * @return bool
2534          */
2535         public function isSemiProtected( $action = 'edit' ) {
2536                 global $wgSemiprotectedRestrictionLevels;
2537
2538                 $restrictions = $this->getRestrictions( $action );
2539                 $semi = $wgSemiprotectedRestrictionLevels;
2540                 if ( !$restrictions || !$semi ) {
2541                         // Not protected, or all protection is full protection
2542                         return false;
2543                 }
2544
2545                 // Remap autoconfirmed to editsemiprotected for BC
2546                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2547                         $semi[$key] = 'editsemiprotected';
2548                 }
2549                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2550                         $restrictions[$key] = 'editsemiprotected';
2551                 }
2552
2553                 return !array_diff( $restrictions, $semi );
2554         }
2555
2556         /**
2557          * Does the title correspond to a protected article?
2558          *
2559          * @param string $action the action the page is protected from,
2560          * by default checks all actions.
2561          * @return bool
2562          */
2563         public function isProtected( $action = '' ) {
2564                 global $wgRestrictionLevels;
2565
2566                 $restrictionTypes = $this->getRestrictionTypes();
2567
2568                 # Special pages have inherent protection
2569                 if ( $this->isSpecialPage() ) {
2570                         return true;
2571                 }
2572
2573                 # Check regular protection levels
2574                 foreach ( $restrictionTypes as $type ) {
2575                         if ( $action == $type || $action == '' ) {
2576                                 $r = $this->getRestrictions( $type );
2577                                 foreach ( $wgRestrictionLevels as $level ) {
2578                                         if ( in_array( $level, $r ) && $level != '' ) {
2579                                                 return true;
2580                                         }
2581                                 }
2582                         }
2583                 }
2584
2585                 return false;
2586         }
2587
2588         /**
2589          * Determines if $user is unable to edit this page because it has been protected
2590          * by $wgNamespaceProtection.
2591          *
2592          * @param User $user User object to check permissions
2593          * @return bool
2594          */
2595         public function isNamespaceProtected( User $user ) {
2596                 global $wgNamespaceProtection;
2597
2598                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2599                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2600                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2601                                         return true;
2602                                 }
2603                         }
2604                 }
2605                 return false;
2606         }
2607
2608         /**
2609          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2610          *
2611          * @return bool If the page is subject to cascading restrictions.
2612          */
2613         public function isCascadeProtected() {
2614                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2615                 return ( $sources > 0 );
2616         }
2617
2618         /**
2619          * Determines whether cascading protection sources have already been loaded from
2620          * the database.
2621          *
2622          * @param bool $getPages True to check if the pages are loaded, or false to check
2623          * if the status is loaded.
2624          * @return bool Whether or not the specified information has been loaded
2625          * @since 1.23
2626          */
2627         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2628                 return $getPages ? isset( $this->mCascadeSources ) : isset( $this->mHasCascadingRestrictions );
2629         }
2630
2631         /**
2632          * Cascading protection: Get the source of any cascading restrictions on this page.
2633          *
2634          * @param bool $getPages Whether or not to retrieve the actual pages
2635          *        that the restrictions have come from.
2636          * @return array|bool Array of Title objects of the pages from which cascading restrictions
2637          *     have come, false for none, or true if such restrictions exist, but $getPages
2638          *     was not set.  The restriction array is an array of each type, each of which
2639          *     contains a array of unique groups.
2640          */
2641         public function getCascadeProtectionSources( $getPages = true ) {
2642                 global $wgContLang;
2643                 $pagerestrictions = array();
2644
2645                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2646                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2647                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2648                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2649                 }
2650
2651                 wfProfileIn( __METHOD__ );
2652
2653                 $dbr = wfGetDB( DB_SLAVE );
2654
2655                 if ( $this->getNamespace() == NS_FILE ) {
2656                         $tables = array( 'imagelinks', 'page_restrictions' );
2657                         $where_clauses = array(
2658                                 'il_to' => $this->getDBkey(),
2659                                 'il_from=pr_page',
2660                                 'pr_cascade' => 1
2661                         );
2662                 } else {
2663                         $tables = array( 'templatelinks', 'page_restrictions' );
2664                         $where_clauses = array(
2665                                 'tl_namespace' => $this->getNamespace(),
2666                                 'tl_title' => $this->getDBkey(),
2667                                 'tl_from=pr_page',
2668                                 'pr_cascade' => 1
2669                         );
2670                 }
2671
2672                 if ( $getPages ) {
2673                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2674                                 'pr_expiry', 'pr_type', 'pr_level' );
2675                         $where_clauses[] = 'page_id=pr_page';
2676                         $tables[] = 'page';
2677                 } else {
2678                         $cols = array( 'pr_expiry' );
2679                 }
2680
2681                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2682
2683                 $sources = $getPages ? array() : false;
2684                 $now = wfTimestampNow();
2685                 $purgeExpired = false;
2686
2687                 foreach ( $res as $row ) {
2688                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2689                         if ( $expiry > $now ) {
2690                                 if ( $getPages ) {
2691                                         $page_id = $row->pr_page;
2692                                         $page_ns = $row->page_namespace;
2693                                         $page_title = $row->page_title;
2694                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2695                                         # Add groups needed for each restriction type if its not already there
2696                                         # Make sure this restriction type still exists
2697
2698                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2699                                                 $pagerestrictions[$row->pr_type] = array();
2700                                         }
2701
2702                                         if (
2703                                                 isset( $pagerestrictions[$row->pr_type] )
2704                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2705                                         ) {
2706                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2707                                         }
2708                                 } else {
2709                                         $sources = true;
2710                                 }
2711                         } else {
2712                                 // Trigger lazy purge of expired restrictions from the db
2713                                 $purgeExpired = true;
2714                         }
2715                 }
2716                 if ( $purgeExpired ) {
2717                         Title::purgeExpiredRestrictions();
2718                 }
2719
2720                 if ( $getPages ) {
2721                         $this->mCascadeSources = $sources;
2722                         $this->mCascadingRestrictions = $pagerestrictions;
2723                 } else {
2724                         $this->mHasCascadingRestrictions = $sources;
2725                 }
2726
2727                 wfProfileOut( __METHOD__ );
2728                 return array( $sources, $pagerestrictions );
2729         }
2730
2731         /**
2732          * Accessor for mRestrictionsLoaded
2733          *
2734          * @return bool Whether or not the page's restrictions have already been
2735          * loaded from the database
2736          * @since 1.23
2737          */
2738         public function areRestrictionsLoaded() {
2739                 return $this->mRestrictionsLoaded;
2740         }
2741
2742         /**
2743          * Accessor/initialisation for mRestrictions
2744          *
2745          * @param string $action Action that permission needs to be checked for
2746          * @return array Array of Strings the array of groups allowed to edit this article
2747          */
2748         public function getRestrictions( $action ) {
2749                 if ( !$this->mRestrictionsLoaded ) {
2750                         $this->loadRestrictions();
2751                 }
2752                 return isset( $this->mRestrictions[$action] )
2753                                 ? $this->mRestrictions[$action]
2754                                 : array();
2755         }
2756
2757         /**
2758          * Accessor/initialisation for mRestrictions
2759          *
2760          * @return array Array of Arrays of Strings the first level indexed by
2761          * action, the second level containing the names of the groups
2762          * allowed to perform each action
2763          * @since 1.23
2764          */
2765         public function getAllRestrictions() {
2766                 if ( !$this->mRestrictionsLoaded ) {
2767                         $this->loadRestrictions();
2768                 }
2769                 return $this->mRestrictions;
2770         }
2771
2772         /**
2773          * Get the expiry time for the restriction against a given action
2774          *
2775          * @param string $action
2776          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2777          *     or not protected at all, or false if the action is not recognised.
2778          */
2779         public function getRestrictionExpiry( $action ) {
2780                 if ( !$this->mRestrictionsLoaded ) {
2781                         $this->loadRestrictions();
2782                 }
2783                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2784         }
2785
2786         /**
2787          * Returns cascading restrictions for the current article
2788          *
2789          * @return bool
2790          */
2791         function areRestrictionsCascading() {
2792                 if ( !$this->mRestrictionsLoaded ) {
2793                         $this->loadRestrictions();
2794                 }
2795
2796                 return $this->mCascadeRestriction;
2797         }
2798
2799         /**
2800          * Loads a string into mRestrictions array
2801          *
2802          * @param ResultWrapper $res Resource restrictions as an SQL result.
2803          * @param string $oldFashionedRestrictions Comma-separated list of page
2804          *        restrictions from page table (pre 1.10)
2805          */
2806         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2807                 $rows = array();
2808
2809                 foreach ( $res as $row ) {
2810                         $rows[] = $row;
2811                 }
2812
2813                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2814         }
2815
2816         /**
2817          * Compiles list of active page restrictions from both page table (pre 1.10)
2818          * and page_restrictions table for this existing page.
2819          * Public for usage by LiquidThreads.
2820          *
2821          * @param array $rows Array of db result objects
2822          * @param string $oldFashionedRestrictions Comma-separated list of page
2823          *   restrictions from page table (pre 1.10)
2824          */
2825         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2826                 global $wgContLang;
2827                 $dbr = wfGetDB( DB_SLAVE );
2828
2829                 $restrictionTypes = $this->getRestrictionTypes();
2830
2831                 foreach ( $restrictionTypes as $type ) {
2832                         $this->mRestrictions[$type] = array();
2833                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2834                 }
2835
2836                 $this->mCascadeRestriction = false;
2837
2838                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2839
2840                 if ( $oldFashionedRestrictions === null ) {
2841                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2842                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2843                 }
2844
2845                 if ( $oldFashionedRestrictions != '' ) {
2846
2847                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2848                                 $temp = explode( '=', trim( $restrict ) );
2849                                 if ( count( $temp ) == 1 ) {
2850                                         // old old format should be treated as edit/move restriction
2851                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2852                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2853                                 } else {
2854                                         $restriction = trim( $temp[1] );
2855                                         if ( $restriction != '' ) { //some old entries are empty
2856                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2857                                         }
2858                                 }
2859                         }
2860
2861                         $this->mOldRestrictions = true;
2862
2863                 }
2864
2865                 if ( count( $rows ) ) {
2866                         # Current system - load second to make them override.
2867                         $now = wfTimestampNow();
2868                         $purgeExpired = false;
2869
2870                         # Cycle through all the restrictions.
2871                         foreach ( $rows as $row ) {
2872
2873                                 // Don't take care of restrictions types that aren't allowed
2874                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2875                                         continue;
2876                                 }
2877
2878                                 // This code should be refactored, now that it's being used more generally,
2879                                 // But I don't really see any harm in leaving it in Block for now -werdna
2880                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2881
2882                                 // Only apply the restrictions if they haven't expired!
2883                                 if ( !$expiry || $expiry > $now ) {
2884                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2885                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2886
2887                                         $this->mCascadeRestriction |= $row->pr_cascade;
2888                                 } else {
2889                                         // Trigger a lazy purge of expired restrictions
2890                                         $purgeExpired = true;
2891                                 }
2892                         }
2893
2894                         if ( $purgeExpired ) {
2895                                 Title::purgeExpiredRestrictions();
2896                         }
2897                 }
2898
2899                 $this->mRestrictionsLoaded = true;
2900         }
2901
2902         /**
2903          * Load restrictions from the page_restrictions table
2904          *
2905          * @param string $oldFashionedRestrictions Comma-separated list of page
2906          *   restrictions from page table (pre 1.10)
2907          */
2908         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2909                 global $wgContLang;
2910                 if ( !$this->mRestrictionsLoaded ) {
2911                         if ( $this->exists() ) {
2912                                 $dbr = wfGetDB( DB_SLAVE );
2913
2914                                 $res = $dbr->select(
2915                                         'page_restrictions',
2916                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2917                                         array( 'pr_page' => $this->getArticleID() ),
2918                                         __METHOD__
2919                                 );
2920
2921                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2922                         } else {
2923                                 $title_protection = $this->getTitleProtection();
2924
2925                                 if ( $title_protection ) {
2926                                         $now = wfTimestampNow();
2927                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2928
2929                                         if ( !$expiry || $expiry > $now ) {
2930                                                 // Apply the restrictions
2931                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2932                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2933                                         } else { // Get rid of the old restrictions
2934                                                 Title::purgeExpiredRestrictions();
2935                                                 $this->mTitleProtection = false;
2936                                         }
2937                                 } else {
2938                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2939                                 }
2940                                 $this->mRestrictionsLoaded = true;
2941                         }
2942                 }
2943         }
2944
2945         /**
2946          * Flush the protection cache in this object and force reload from the database.
2947          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2948          */
2949         public function flushRestrictions() {
2950                 $this->mRestrictionsLoaded = false;
2951                 $this->mTitleProtection = null;
2952         }
2953
2954         /**
2955          * Purge expired restrictions from the page_restrictions table
2956          */
2957         static function purgeExpiredRestrictions() {
2958                 if ( wfReadOnly() ) {
2959                         return;
2960                 }
2961
2962                 $method = __METHOD__;
2963                 $dbw = wfGetDB( DB_MASTER );
2964                 $dbw->onTransactionIdle( function() use ( $dbw, $method ) {
2965                         $dbw->delete(
2966                                 'page_restrictions',
2967                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2968                                 $method
2969                         );
2970                         $dbw->delete(
2971                                 'protected_titles',
2972                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2973                                 $method
2974                         );
2975                 } );
2976         }
2977
2978         /**
2979          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2980          *
2981          * @return bool
2982          */
2983         public function hasSubpages() {
2984                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2985                         # Duh
2986                         return false;
2987                 }
2988
2989                 # We dynamically add a member variable for the purpose of this method
2990                 # alone to cache the result.  There's no point in having it hanging
2991                 # around uninitialized in every Title object; therefore we only add it
2992                 # if needed and don't declare it statically.
2993                 if ( !isset( $this->mHasSubpages ) ) {
2994                         $this->mHasSubpages = false;
2995                         $subpages = $this->getSubpages( 1 );
2996                         if ( $subpages instanceof TitleArray ) {
2997                                 $this->mHasSubpages = (bool)$subpages->count();
2998                         }
2999                 }
3000
3001                 return $this->mHasSubpages;
3002         }
3003
3004         /**
3005          * Get all subpages of this page.
3006          *
3007          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3008          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3009          *  doesn't allow subpages
3010          */
3011         public function getSubpages( $limit = -1 ) {
3012                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3013                         return array();
3014                 }
3015
3016                 $dbr = wfGetDB( DB_SLAVE );
3017                 $conds['page_namespace'] = $this->getNamespace();
3018                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3019                 $options = array();
3020                 if ( $limit > -1 ) {
3021                         $options['LIMIT'] = $limit;
3022                 }
3023                 $this->mSubpages = TitleArray::newFromResult(
3024                         $dbr->select( 'page',
3025                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3026                                 $conds,
3027                                 __METHOD__,
3028                                 $options
3029                         )
3030                 );
3031                 return $this->mSubpages;
3032         }
3033
3034         /**
3035          * Is there a version of this page in the deletion archive?
3036          *
3037          * @return int The number of archived revisions
3038          */
3039         public function isDeleted() {
3040                 if ( $this->getNamespace() < 0 ) {
3041                         $n = 0;
3042                 } else {
3043                         $dbr = wfGetDB( DB_SLAVE );
3044
3045                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3046                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3047                                 __METHOD__
3048                         );
3049                         if ( $this->getNamespace() == NS_FILE ) {
3050                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3051                                         array( 'fa_name' => $this->getDBkey() ),
3052                                         __METHOD__
3053                                 );
3054                         }
3055                 }
3056                 return (int)$n;
3057         }
3058
3059         /**
3060          * Is there a version of this page in the deletion archive?
3061          *
3062          * @return bool
3063          */
3064         public function isDeletedQuick() {
3065                 if ( $this->getNamespace() < 0 ) {
3066                         return false;
3067                 }
3068                 $dbr = wfGetDB( DB_SLAVE );
3069                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3070                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3071                         __METHOD__
3072                 );
3073                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3074                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3075                                 array( 'fa_name' => $this->getDBkey() ),
3076                                 __METHOD__
3077                         );
3078                 }
3079                 return $deleted;
3080         }
3081
3082         /**
3083          * Get the article ID for this Title from the link cache,
3084          * adding it if necessary
3085          *
3086          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3087          *  for update
3088          * @return int The ID
3089          */
3090         public function getArticleID( $flags = 0 ) {
3091                 if ( $this->getNamespace() < 0 ) {
3092                         $this->mArticleID = 0;
3093                         return $this->mArticleID;
3094                 }
3095                 $linkCache = LinkCache::singleton();
3096                 if ( $flags & self::GAID_FOR_UPDATE ) {
3097                         $oldUpdate = $linkCache->forUpdate( true );
3098                         $linkCache->clearLink( $this );
3099                         $this->mArticleID = $linkCache->addLinkObj( $this );
3100                         $linkCache->forUpdate( $oldUpdate );
3101                 } else {
3102                         if ( -1 == $this->mArticleID ) {
3103                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3104                         }
3105                 }
3106                 return $this->mArticleID;
3107         }
3108
3109         /**
3110          * Is this an article that is a redirect page?
3111          * Uses link cache, adding it if necessary
3112          *
3113          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3114          * @return bool
3115          */
3116         public function isRedirect( $flags = 0 ) {
3117                 if ( !is_null( $this->mRedirect ) ) {
3118                         return $this->mRedirect;
3119                 }
3120                 # Calling getArticleID() loads the field from cache as needed
3121                 if ( !$this->getArticleID( $flags ) ) {
3122                         $this->mRedirect = false;
3123                         return $this->mRedirect;
3124                 }
3125
3126                 $linkCache = LinkCache::singleton();
3127                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3128                 if ( $cached === null ) {
3129                         # Trust LinkCache's state over our own
3130                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3131                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3132                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3133                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3134                         # LinkCache to refresh its data from the master.
3135                         $this->mRedirect = false;
3136                         return $this->mRedirect;
3137                 }
3138
3139                 $this->mRedirect = (bool)$cached;
3140
3141                 return $this->mRedirect;
3142         }
3143
3144         /**
3145          * What is the length of this page?
3146          * Uses link cache, adding it if necessary
3147          *
3148          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3149          * @return int
3150          */
3151         public function getLength( $flags = 0 ) {
3152                 if ( $this->mLength != -1 ) {
3153                         return $this->mLength;
3154                 }
3155                 # Calling getArticleID() loads the field from cache as needed
3156                 if ( !$this->getArticleID( $flags ) ) {
3157                         $this->mLength = 0;
3158                         return $this->mLength;
3159                 }
3160                 $linkCache = LinkCache::singleton();
3161                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3162                 if ( $cached === null ) {
3163                         # Trust LinkCache's state over our own, as for isRedirect()
3164                         $this->mLength = 0;
3165                         return $this->mLength;
3166                 }
3167
3168                 $this->mLength = intval( $cached );
3169
3170                 return $this->mLength;
3171         }
3172
3173         /**
3174          * What is the page_latest field for this page?
3175          *
3176          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3177          * @return int Int or 0 if the page doesn't exist
3178          */
3179         public function getLatestRevID( $flags = 0 ) {
3180                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3181                         return intval( $this->mLatestID );
3182                 }
3183                 # Calling getArticleID() loads the field from cache as needed
3184                 if ( !$this->getArticleID( $flags ) ) {
3185                         $this->mLatestID = 0;
3186                         return $this->mLatestID;
3187                 }
3188                 $linkCache = LinkCache::singleton();
3189                 $linkCache->addLinkObj( $this );
3190                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3191                 if ( $cached === null ) {
3192                         # Trust LinkCache's state over our own, as for isRedirect()
3193                         $this->mLatestID = 0;
3194                         return $this->mLatestID;
3195                 }
3196
3197                 $this->mLatestID = intval( $cached );
3198
3199                 return $this->mLatestID;
3200         }
3201
3202         /**
3203          * This clears some fields in this object, and clears any associated
3204          * keys in the "bad links" section of the link cache.
3205          *
3206          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3207          * loading of the new page_id. It's also called from
3208          * WikiPage::doDeleteArticleReal()
3209          *
3210          * @param int $newid The new Article ID
3211          */
3212         public function resetArticleID( $newid ) {
3213                 $linkCache = LinkCache::singleton();
3214                 $linkCache->clearLink( $this );
3215
3216                 if ( $newid === false ) {
3217                         $this->mArticleID = -1;
3218                 } else {
3219                         $this->mArticleID = intval( $newid );
3220                 }
3221                 $this->mRestrictionsLoaded = false;
3222                 $this->mRestrictions = array();
3223                 $this->mRedirect = null;
3224                 $this->mLength = -1;
3225                 $this->mLatestID = false;
3226                 $this->mContentModel = false;
3227                 $this->mEstimateRevisions = null;
3228                 $this->mPageLanguage = false;
3229         }
3230
3231         /**
3232          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3233          *
3234          * @param string $text Containing title to capitalize
3235          * @param int $ns Namespace index, defaults to NS_MAIN
3236          * @return string Containing capitalized title
3237          */
3238         public static function capitalize( $text, $ns = NS_MAIN ) {
3239                 global $wgContLang;
3240
3241                 if ( MWNamespace::isCapitalized( $ns ) ) {
3242                         return $wgContLang->ucfirst( $text );
3243                 } else {
3244                         return $text;
3245                 }
3246         }
3247
3248         /**
3249          * Secure and split - main initialisation function for this object
3250          *
3251          * Assumes that mDbkeyform has been set, and is urldecoded
3252          * and uses underscores, but not otherwise munged.  This function
3253          * removes illegal characters, splits off the interwiki and
3254          * namespace prefixes, sets the other forms, and canonicalizes
3255          * everything.
3256          *
3257          * @return bool True on success
3258          */
3259         private function secureAndSplit() {
3260                 # Initialisation
3261                 $this->mInterwiki = '';
3262                 $this->mFragment = '';
3263                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3264
3265                 $dbkey = $this->mDbkeyform;
3266
3267                 try {
3268                         // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3269                         //        the parsing code with Title, while avoiding massive refactoring.
3270                         // @todo: get rid of secureAndSplit, refactor parsing code.
3271                         $parser = $this->getTitleParser();
3272                         $parts = $parser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3273                 } catch ( MalformedTitleException $ex ) {
3274                         return false;
3275                 }
3276
3277                 # Fill fields
3278                 $this->setFragment( '#' . $parts['fragment'] );
3279                 $this->mInterwiki = $parts['interwiki'];
3280                 $this->mNamespace = $parts['namespace'];
3281                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3282
3283                 $this->mDbkeyform = $parts['dbkey'];
3284                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3285                 $this->mTextform = str_replace( '_', ' ', $this->mDbkeyform );
3286
3287                 # We already know that some pages won't be in the database!
3288                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3289                         $this->mArticleID = 0;
3290                 }
3291
3292                 return true;
3293         }
3294
3295         /**
3296          * Get an array of Title objects linking to this Title
3297          * Also stores the IDs in the link cache.
3298          *
3299          * WARNING: do not use this function on arbitrary user-supplied titles!
3300          * On heavily-used templates it will max out the memory.
3301          *
3302          * @param array $options May be FOR UPDATE
3303          * @param string $table Table name
3304          * @param string $prefix Fields prefix
3305          * @return Title[] Array of Title objects linking here
3306          */
3307         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3308                 if ( count( $options ) > 0 ) {
3309                         $db = wfGetDB( DB_MASTER );
3310                 } else {
3311                         $db = wfGetDB( DB_SLAVE );
3312                 }
3313
3314                 $res = $db->select(
3315                         array( 'page', $table ),
3316                         self::getSelectFields(),
3317                         array(
3318                                 "{$prefix}_from=page_id",
3319                                 "{$prefix}_namespace" => $this->getNamespace(),
3320                                 "{$prefix}_title" => $this->getDBkey() ),
3321                         __METHOD__,
3322                         $options
3323                 );
3324
3325                 $retVal = array();
3326                 if ( $res->numRows() ) {
3327                         $linkCache = LinkCache::singleton();
3328                         foreach ( $res as $row ) {
3329                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3330                                 if ( $titleObj ) {
3331                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3332                                         $retVal[] = $titleObj;
3333                                 }
3334                         }
3335                 }
3336                 return $retVal;
3337         }
3338
3339         /**
3340          * Get an array of Title objects using this Title as a template
3341          * Also stores the IDs in the link cache.
3342          *
3343          * WARNING: do not use this function on arbitrary user-supplied titles!
3344          * On heavily-used templates it will max out the memory.
3345          *
3346          * @param array $options May be FOR UPDATE
3347          * @return Title[] Array of Title the Title objects linking here
3348          */
3349         public function getTemplateLinksTo( $options = array() ) {
3350                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3351         }
3352
3353         /**
3354          * Get an array of Title objects linked from this Title
3355          * Also stores the IDs in the link cache.
3356          *
3357          * WARNING: do not use this function on arbitrary user-supplied titles!
3358          * On heavily-used templates it will max out the memory.
3359          *
3360          * @param array $options May be FOR UPDATE
3361          * @param string $table Table name
3362          * @param string $prefix Fields prefix
3363          * @return array Array of Title objects linking here
3364          */
3365         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3366                 global $wgContentHandlerUseDB;
3367
3368                 $id = $this->getArticleID();
3369
3370                 # If the page doesn't exist; there can't be any link from this page
3371                 if ( !$id ) {
3372                         return array();
3373                 }
3374
3375                 if ( count( $options ) > 0 ) {
3376                         $db = wfGetDB( DB_MASTER );
3377                 } else {
3378                         $db = wfGetDB( DB_SLAVE );
3379                 }
3380
3381                 $namespaceFiled = "{$prefix}_namespace";
3382                 $titleField = "{$prefix}_title";
3383
3384                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3385                 if ( $wgContentHandlerUseDB ) {
3386                         $fields[] = 'page_content_model';
3387                 }
3388
3389                 $res = $db->select(
3390                         array( $table, 'page' ),
3391                         $fields,
3392                         array( "{$prefix}_from" => $id ),
3393                         __METHOD__,
3394                         $options,
3395                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3396                 );
3397
3398                 $retVal = array();
3399                 if ( $res->numRows() ) {
3400                         $linkCache = LinkCache::singleton();
3401                         foreach ( $res as $row ) {
3402                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3403                                 if ( $titleObj ) {
3404                                         if ( $row->page_id ) {
3405                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3406                                         } else {
3407                                                 $linkCache->addBadLinkObj( $titleObj );
3408                                         }
3409                                         $retVal[] = $titleObj;
3410                                 }
3411                         }
3412                 }
3413                 return $retVal;
3414         }
3415
3416         /**
3417          * Get an array of Title objects used on this Title as a template
3418          * Also stores the IDs in the link cache.
3419          *
3420          * WARNING: do not use this function on arbitrary user-supplied titles!
3421          * On heavily-used templates it will max out the memory.
3422          *
3423          * @param array $options May be FOR UPDATE
3424          * @return Title[] Array of Title the Title objects used here
3425          */
3426         public function getTemplateLinksFrom( $options = array() ) {
3427                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3428         }
3429
3430         /**
3431          * Get an array of Title objects referring to non-existent articles linked from this page
3432          *
3433          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3434          * @return Title[] Array of Title the Title objects
3435          */
3436         public function getBrokenLinksFrom() {
3437                 if ( $this->getArticleID() == 0 ) {
3438                         # All links from article ID 0 are false positives
3439                         return array();
3440                 }
3441
3442                 $dbr = wfGetDB( DB_SLAVE );
3443                 $res = $dbr->select(
3444                         array( 'page', 'pagelinks' ),
3445                         array( 'pl_namespace', 'pl_title' ),
3446                         array(
3447                                 'pl_from' => $this->getArticleID(),
3448                                 'page_namespace IS NULL'
3449                         ),
3450                         __METHOD__, array(),
3451                         array(
3452                                 'page' => array(
3453                                         'LEFT JOIN',
3454                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3455                                 )
3456                         )
3457                 );
3458
3459                 $retVal = array();
3460                 foreach ( $res as $row ) {
3461                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3462                 }
3463                 return $retVal;
3464         }
3465
3466         /**
3467          * Get a list of URLs to purge from the Squid cache when this
3468          * page changes
3469          *
3470          * @return string[] Array of String the URLs
3471          */
3472         public function getSquidURLs() {
3473                 $urls = array(
3474                         $this->getInternalURL(),
3475                         $this->getInternalURL( 'action=history' )
3476                 );
3477
3478                 $pageLang = $this->getPageLanguage();
3479                 if ( $pageLang->hasVariants() ) {
3480                         $variants = $pageLang->getVariants();
3481                         foreach ( $variants as $vCode ) {
3482                                 $urls[] = $this->getInternalURL( '', $vCode );
3483                         }
3484                 }
3485
3486                 // If we are looking at a css/js user subpage, purge the action=raw.
3487                 if ( $this->isJsSubpage() ) {
3488                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3489                 } elseif ( $this->isCssSubpage() ) {
3490                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3491                 }
3492
3493                 wfRunHooks( 'TitleSquidURLs', array( $this, &$urls ) );
3494                 return $urls;
3495         }
3496
3497         /**
3498          * Purge all applicable Squid URLs
3499          */
3500         public function purgeSquid() {
3501                 global $wgUseSquid;
3502                 if ( $wgUseSquid ) {
3503                         $urls = $this->getSquidURLs();
3504                         $u = new SquidUpdate( $urls );
3505                         $u->doUpdate();
3506                 }
3507         }
3508
3509         /**
3510          * Move this page without authentication
3511          *
3512          * @param Title $nt The new page Title
3513          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3514          */
3515         public function moveNoAuth( &$nt ) {
3516                 return $this->moveTo( $nt, false );
3517         }
3518
3519         /**
3520          * Check whether a given move operation would be valid.
3521          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3522          *
3523          * @param Title $nt The new title
3524          * @param bool $auth Indicates whether $wgUser's permissions
3525          *  should be checked
3526          * @param string $reason Is the log summary of the move, used for spam checking
3527          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3528          */
3529         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3530                 global $wgUser, $wgContentHandlerUseDB;
3531
3532                 $errors = array();
3533                 if ( !$nt ) {
3534                         // Normally we'd add this to $errors, but we'll get
3535                         // lots of syntax errors if $nt is not an object
3536                         return array( array( 'badtitletext' ) );
3537                 }
3538                 if ( $this->equals( $nt ) ) {
3539                         $errors[] = array( 'selfmove' );
3540                 }
3541                 if ( !$this->isMovable() ) {
3542                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3543                 }
3544                 if ( $nt->isExternal() ) {
3545                         $errors[] = array( 'immobile-target-namespace-iw' );
3546                 }
3547                 if ( !$nt->isMovable() ) {
3548                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3549                 }
3550
3551                 $oldid = $this->getArticleID();
3552                 $newid = $nt->getArticleID();
3553
3554                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3555                         $errors[] = array( 'articleexists' );
3556                 }
3557                 if (
3558                         ( $this->getDBkey() == '' ) ||
3559                         ( !$oldid ) ||
3560                         ( $nt->getDBkey() == '' )
3561                 ) {
3562                         $errors[] = array( 'badarticleerror' );
3563                 }
3564
3565                 // Content model checks
3566                 if ( !$wgContentHandlerUseDB &&
3567                                 $this->getContentModel() !== $nt->getContentModel() ) {
3568                         // can't move a page if that would change the page's content model
3569                         $errors[] = array(
3570                                 'bad-target-model',
3571                                 ContentHandler::getLocalizedName( $this->getContentModel() ),
3572                                 ContentHandler::getLocalizedName( $nt->getContentModel() )
3573                         );
3574                 }
3575
3576                 // Image-specific checks
3577                 if ( $this->getNamespace() == NS_FILE ) {
3578                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3579                 }
3580
3581                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3582                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3583                 }
3584
3585                 if ( $auth ) {
3586                         $errors = wfMergeErrorArrays( $errors,
3587                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3588                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3589                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3590                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3591                 }
3592
3593                 $match = EditPage::matchSummarySpamRegex( $reason );
3594                 if ( $match !== false ) {
3595                         // This is kind of lame, won't display nice
3596                         $errors[] = array( 'spamprotectiontext' );
3597                 }
3598
3599                 $err = null;
3600                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3601                         $errors[] = array( 'hookaborted', $err );
3602                 }
3603
3604                 # The move is allowed only if (1) the target doesn't exist, or
3605                 # (2) the target is a redirect to the source, and has no history
3606                 # (so we can undo bad moves right after they're done).
3607
3608                 if ( 0 != $newid ) { # Target exists; check for validity
3609                         if ( !$this->isValidMoveTarget( $nt ) ) {
3610                                 $errors[] = array( 'articleexists' );
3611                         }
3612                 } else {
3613                         $tp = $nt->getTitleProtection();
3614                         $right = $tp['pt_create_perm'];
3615                         if ( $right == 'sysop' ) {
3616                                 $right = 'editprotected'; // B/C
3617                         }
3618                         if ( $right == 'autoconfirmed' ) {
3619                                 $right = 'editsemiprotected'; // B/C
3620                         }
3621                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3622                                 $errors[] = array( 'cantmove-titleprotected' );
3623                         }
3624                 }
3625                 if ( empty( $errors ) ) {
3626                         return true;
3627                 }
3628                 return $errors;
3629         }
3630
3631         /**
3632          * Check if the requested move target is a valid file move target
3633          * @param Title $nt Target title
3634          * @return array List of errors
3635          */
3636         protected function validateFileMoveOperation( $nt ) {
3637                 global $wgUser;
3638
3639                 $errors = array();
3640
3641                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3642
3643                 $file = wfLocalFile( $this );
3644                 if ( $file->exists() ) {
3645                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3646                                 $errors[] = array( 'imageinvalidfilename' );
3647                         }
3648                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3649                                 $errors[] = array( 'imagetypemismatch' );
3650                         }
3651                 }
3652
3653                 if ( $nt->getNamespace() != NS_FILE ) {
3654                         $errors[] = array( 'imagenocrossnamespace' );
3655                         // From here we want to do checks on a file object, so if we can't
3656                         // create one, we must return.
3657                         return $errors;
3658                 }
3659
3660                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3661
3662                 $destFile = wfLocalFile( $nt );
3663                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3664                         $errors[] = array( 'file-exists-sharedrepo' );
3665                 }
3666
3667                 return $errors;
3668         }
3669
3670         /**
3671          * Move a title to a new location
3672          *
3673          * @param Title $nt The new title
3674          * @param bool $auth Indicates whether $wgUser's permissions
3675          *  should be checked
3676          * @param string $reason The reason for the move
3677          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3678          *  Ignored if the user doesn't have the suppressredirect right.
3679          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3680          */
3681         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3682                 global $wgUser;
3683                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3684                 if ( is_array( $err ) ) {
3685                         // Auto-block user's IP if the account was "hard" blocked
3686                         $wgUser->spreadAnyEditBlock();
3687                         return $err;
3688                 }
3689                 // Check suppressredirect permission
3690                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3691                         $createRedirect = true;
3692                 }
3693
3694                 wfRunHooks( 'TitleMove', array( $this, $nt, $wgUser ) );
3695
3696                 // If it is a file, move it first.
3697                 // It is done before all other moving stuff is done because it's hard to revert.
3698                 $dbw = wfGetDB( DB_MASTER );
3699                 if ( $this->getNamespace() == NS_FILE ) {
3700                         $file = wfLocalFile( $this );
3701                         if ( $file->exists() ) {
3702                                 $status = $file->move( $nt );
3703                                 if ( !$status->isOk() ) {
3704                                         return $status->getErrorsArray();
3705                                 }
3706                         }
3707                         // Clear RepoGroup process cache
3708                         RepoGroup::singleton()->clearCache( $this );
3709                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3710                 }
3711
3712                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3713                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3714                 $protected = $this->isProtected();
3715
3716                 // Do the actual move
3717                 $this->moveToInternal( $nt, $reason, $createRedirect );
3718
3719                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3720                 // cl_timestamp, which may disturb time-based lists on some sites.
3721                 $prefixes = $dbw->select(
3722                         'categorylinks',
3723                         array( 'cl_sortkey_prefix', 'cl_to' ),
3724                         array( 'cl_from' => $pageid ),
3725                         __METHOD__
3726                 );
3727                 foreach ( $prefixes as $prefixRow ) {
3728                         $prefix = $prefixRow->cl_sortkey_prefix;
3729                         $catTo = $prefixRow->cl_to;
3730                         $dbw->update( 'categorylinks',
3731                                 array(
3732                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3733                                                 $nt->getCategorySortkey( $prefix ) ),
3734                                         'cl_timestamp=cl_timestamp' ),
3735                                 array(
3736                                         'cl_from' => $pageid,
3737                                         'cl_to' => $catTo ),
3738                                 __METHOD__
3739                         );
3740                 }
3741
3742                 $redirid = $this->getArticleID();
3743
3744                 if ( $protected ) {
3745                         # Protect the redirect title as the title used to be...
3746                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3747                                 array(
3748                                         'pr_page' => $redirid,
3749                                         'pr_type' => 'pr_type',
3750                                         'pr_level' => 'pr_level',
3751                                         'pr_cascade' => 'pr_cascade',
3752                                         'pr_user' => 'pr_user',
3753                                         'pr_expiry' => 'pr_expiry'
3754                                 ),
3755                                 array( 'pr_page' => $pageid ),
3756                                 __METHOD__,
3757                                 array( 'IGNORE' )
3758                         );
3759                         # Update the protection log
3760                         $log = new LogPage( 'protect' );
3761                         $comment = wfMessage(
3762                                 'prot_1movedto2',
3763                                 $this->getPrefixedText(),
3764                                 $nt->getPrefixedText()
3765                         )->inContentLanguage()->text();
3766                         if ( $reason ) {
3767                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3768                         }
3769                         // @todo FIXME: $params?
3770                         $logId = $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ), $wgUser );
3771
3772                         // reread inserted pr_ids for log relation
3773                         $insertedPrIds = $dbw->select(
3774                                 'page_restrictions',
3775                                 'pr_id',
3776                                 array( 'pr_page' => $redirid ),
3777                                 __METHOD__
3778                         );
3779                         $logRelationsValues = array();
3780                         foreach ( $insertedPrIds as $prid ) {
3781                                 $logRelationsValues[] = $prid->pr_id;
3782                         }
3783                         $log->addRelations( 'pr_id', $logRelationsValues, $logId );
3784                 }
3785
3786                 # Update watchlists
3787                 $oldnamespace = MWNamespace::getSubject( $this->getNamespace() );
3788                 $newnamespace = MWNamespace::getSubject( $nt->getNamespace() );
3789                 $oldtitle = $this->getDBkey();
3790                 $newtitle = $nt->getDBkey();
3791
3792                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3793                         WatchedItem::duplicateEntries( $this, $nt );
3794                 }
3795
3796                 $dbw->commit( __METHOD__ );
3797
3798                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid, $reason ) );
3799                 return true;
3800         }
3801
3802         /**
3803          * Move page to a title which is either a redirect to the
3804          * source page or nonexistent
3805          *
3806          * @param Title $nt The page to move to, which should be a redirect or nonexistent
3807          * @param string $reason The reason for the move
3808          * @param bool $createRedirect Whether to leave a redirect at the old title. Does not check
3809          *   if the user has the suppressredirect right
3810          * @throws MWException
3811          */
3812         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3813                 global $wgUser, $wgContLang;
3814
3815                 if ( $nt->exists() ) {
3816                         $moveOverRedirect = true;
3817                         $logType = 'move_redir';
3818                 } else {
3819                         $moveOverRedirect = false;
3820                         $logType = 'move';
3821                 }
3822
3823                 if ( $createRedirect ) {
3824                         if ( $this->getNamespace() == NS_CATEGORY && !wfMessage( 'category-move-redirect-override' )->isDisabled() ) {
3825                                 $redirectContent = new WikitextContent(
3826                                         wfMessage( 'category-move-redirect-override' )->params( $nt->getPrefixedText() )->inContentLanguage()->plain() );
3827                         } else {
3828                                 $contentHandler = ContentHandler::getForTitle( $this );
3829                                 $redirectContent = $contentHandler->makeRedirectContent( $nt,
3830                                         wfMessage( 'move-redirect-text' )->inContentLanguage()->plain() );
3831                         }
3832
3833                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3834                 } else {
3835                         $redirectContent = null;
3836                 }
3837
3838                 $logEntry = new ManualLogEntry( 'move', $logType );
3839                 $logEntry->setPerformer( $wgUser );
3840                 $logEntry->setTarget( $this );
3841                 $logEntry->setComment( $reason );
3842                 $logEntry->setParameters( array(
3843                         '4::target' => $nt->getPrefixedText(),
3844                         '5::noredir' => $redirectContent ? '0': '1',
3845                 ) );
3846
3847                 $formatter = LogFormatter::newFromEntry( $logEntry );
3848                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3849                 $comment = $formatter->getPlainActionText();
3850                 if ( $reason ) {
3851                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3852                 }
3853                 # Truncate for whole multibyte characters.
3854                 $comment = $wgContLang->truncate( $comment, 255 );
3855
3856                 $oldid = $this->getArticleID();
3857
3858                 $dbw = wfGetDB( DB_MASTER );
3859
3860                 $newpage = WikiPage::factory( $nt );
3861
3862                 if ( $moveOverRedirect ) {
3863                         $newid = $nt->getArticleID();
3864                         $newcontent = $newpage->getContent();
3865
3866                         # Delete the old redirect. We don't save it to history since
3867                         # by definition if we've got here it's rather uninteresting.
3868                         # We have to remove it so that the next step doesn't trigger
3869                         # a conflict on the unique namespace+title index...
3870                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3871
3872                         $newpage->doDeleteUpdates( $newid, $newcontent );
3873                 }
3874
3875                 # Save a null revision in the page's history notifying of the move
3876                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true, $wgUser );
3877                 if ( !is_object( $nullRevision ) ) {
3878                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3879                 }
3880
3881                 $nullRevision->insertOn( $dbw );
3882
3883                 # Change the name of the target page:
3884                 $dbw->update( 'page',
3885                         /* SET */ array(
3886                                 'page_namespace' => $nt->getNamespace(),
3887                                 'page_title' => $nt->getDBkey(),
3888                         ),
3889                         /* WHERE */ array( 'page_id' => $oldid ),
3890                         __METHOD__
3891                 );
3892
3893                 // clean up the old title before reset article id - bug 45348
3894                 if ( !$redirectContent ) {
3895                         WikiPage::onArticleDelete( $this );
3896                 }
3897
3898                 $this->resetArticleID( 0 ); // 0 == non existing
3899                 $nt->resetArticleID( $oldid );
3900                 $newpage->loadPageData( WikiPage::READ_LOCKING ); // bug 46397
3901
3902                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3903
3904                 wfRunHooks( 'NewRevisionFromEditComplete',
3905                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3906
3907                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3908
3909                 if ( !$moveOverRedirect ) {
3910                         WikiPage::onArticleCreate( $nt );
3911                 }
3912
3913                 # Recreate the redirect, this time in the other direction.
3914                 if ( $redirectContent ) {
3915                         $redirectArticle = WikiPage::factory( $this );
3916                         $redirectArticle->loadFromRow( false, WikiPage::READ_LOCKING ); // bug 46397
3917                         $newid = $redirectArticle->insertOn( $dbw );
3918                         if ( $newid ) { // sanity
3919                                 $this->resetArticleID( $newid );
3920                                 $redirectRevision = new Revision( array(
3921                                         'title' => $this, // for determining the default content model
3922                                         'page' => $newid,
3923                                         'user_text' => $wgUser->getName(),
3924                                         'user' => $wgUser->getId(),
3925                                         'comment' => $comment,
3926                                         'content' => $redirectContent ) );
3927                                 $redirectRevision->insertOn( $dbw );
3928                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3929
3930                                 wfRunHooks( 'NewRevisionFromEditComplete',
3931                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3932
3933                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3934                         }
3935                 }
3936
3937                 # Log the move
3938                 $logid = $logEntry->insert();
3939                 $logEntry->publish( $logid );
3940         }
3941
3942         /**
3943          * Move this page's subpages to be subpages of $nt
3944          *
3945          * @param Title $nt Move target
3946          * @param bool $auth Whether $wgUser's permissions should be checked
3947          * @param string $reason The reason for the move
3948          * @param bool $createRedirect Whether to create redirects from the old subpages to
3949          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3950          * @return array Array with old page titles as keys, and strings (new page titles) or
3951          *     arrays (errors) as values, or an error array with numeric indices if no pages
3952          *     were moved
3953          */
3954         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3955                 global $wgMaximumMovedPages;
3956                 // Check permissions
3957                 if ( !$this->userCan( 'move-subpages' ) ) {
3958                         return array( 'cant-move-subpages' );
3959                 }
3960                 // Do the source and target namespaces support subpages?
3961                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3962                         return array( 'namespace-nosubpages',
3963                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3964                 }
3965                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3966                         return array( 'namespace-nosubpages',
3967                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3968                 }
3969
3970                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3971                 $retval = array();
3972                 $count = 0;
3973                 foreach ( $subpages as $oldSubpage ) {
3974                         $count++;
3975                         if ( $count > $wgMaximumMovedPages ) {
3976                                 $retval[$oldSubpage->getPrefixedText()] =
3977                                                 array( 'movepage-max-pages',
3978                                                         $wgMaximumMovedPages );
3979                                 break;
3980                         }
3981
3982                         // We don't know whether this function was called before
3983                         // or after moving the root page, so check both
3984                         // $this and $nt
3985                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3986                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3987                         ) {
3988                                 // When moving a page to a subpage of itself,
3989                                 // don't move it twice
3990                                 continue;
3991                         }
3992                         $newPageName = preg_replace(
3993                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3994                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3995                                         $oldSubpage->getDBkey() );
3996                         if ( $oldSubpage->isTalkPage() ) {
3997                                 $newNs = $nt->getTalkPage()->getNamespace();
3998                         } else {
3999                                 $newNs = $nt->getSubjectPage()->getNamespace();
4000                         }
4001                         # Bug 14385: we need makeTitleSafe because the new page names may
4002                         # be longer than 255 characters.
4003                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
4004
4005                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
4006                         if ( $success === true ) {
4007                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
4008                         } else {
4009                                 $retval[$oldSubpage->getPrefixedText()] = $success;
4010                         }
4011                 }
4012                 return $retval;
4013         }
4014
4015         /**
4016          * Checks if this page is just a one-rev redirect.
4017          * Adds lock, so don't use just for light purposes.
4018          *
4019          * @return bool
4020          */
4021         public function isSingleRevRedirect() {
4022                 global $wgContentHandlerUseDB;
4023
4024                 $dbw = wfGetDB( DB_MASTER );
4025
4026                 # Is it a redirect?
4027                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
4028                 if ( $wgContentHandlerUseDB ) {
4029                         $fields[] = 'page_content_model';
4030                 }
4031
4032                 $row = $dbw->selectRow( 'page',
4033                         $fields,
4034                         $this->pageCond(),
4035                         __METHOD__,
4036                         array( 'FOR UPDATE' )
4037                 );
4038                 # Cache some fields we may want
4039                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
4040                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
4041                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
4042                 $this->mContentModel = $row && isset( $row->page_content_model ) ? strval( $row->page_content_model ) : false;
4043                 if ( !$this->mRedirect ) {
4044                         return false;
4045                 }
4046                 # Does the article have a history?
4047                 $row = $dbw->selectField( array( 'page', 'revision' ),
4048                         'rev_id',
4049                         array( 'page_namespace' => $this->getNamespace(),
4050                                 'page_title' => $this->getDBkey(),
4051                                 'page_id=rev_page',
4052                                 'page_latest != rev_id'
4053                         ),
4054                         __METHOD__,
4055                         array( 'FOR UPDATE' )
4056                 );
4057                 # Return true if there was no history
4058                 return ( $row === false );
4059         }
4060
4061         /**
4062          * Checks if $this can be moved to a given Title
4063          * - Selects for update, so don't call it unless you mean business
4064          *
4065          * @param Title $nt The new title to check
4066          * @return bool
4067          */
4068         public function isValidMoveTarget( $nt ) {
4069                 # Is it an existing file?
4070                 if ( $nt->getNamespace() == NS_FILE ) {
4071                         $file = wfLocalFile( $nt );
4072                         if ( $file->exists() ) {
4073                                 wfDebug( __METHOD__ . ": file exists\n" );
4074                                 return false;
4075                         }
4076                 }
4077                 # Is it a redirect with no history?
4078                 if ( !$nt->isSingleRevRedirect() ) {
4079                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
4080                         return false;
4081                 }
4082                 # Get the article text
4083                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
4084                 if ( !is_object( $rev ) ) {
4085                         return false;
4086                 }
4087                 $content = $rev->getContent();
4088                 # Does the redirect point to the source?
4089                 # Or is it a broken self-redirect, usually caused by namespace collisions?
4090                 $redirTitle = $content ? $content->getRedirectTarget() : null;
4091
4092                 if ( $redirTitle ) {
4093                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
4094                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
4095                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
4096                                 return false;
4097                         } else {
4098                                 return true;
4099                         }
4100                 } else {
4101                         # Fail safe (not a redirect after all. strange.)
4102                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
4103                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
4104                         return false;
4105                 }
4106         }
4107
4108         /**
4109          * Get categories to which this Title belongs and return an array of
4110          * categories' names.
4111          *
4112          * @return array Array of parents in the form:
4113          *        $parent => $currentarticle
4114          */
4115         public function getParentCategories() {
4116                 global $wgContLang;
4117
4118                 $data = array();
4119
4120                 $titleKey = $this->getArticleID();
4121
4122                 if ( $titleKey === 0 ) {
4123                         return $data;
4124                 }
4125
4126                 $dbr = wfGetDB( DB_SLAVE );
4127
4128                 $res = $dbr->select(
4129                         'categorylinks',
4130                         'cl_to',
4131                         array( 'cl_from' => $titleKey ),
4132                         __METHOD__
4133                 );
4134
4135                 if ( $res->numRows() > 0 ) {
4136                         foreach ( $res as $row ) {
4137                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
4138                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4139                         }
4140                 }
4141                 return $data;
4142         }
4143
4144         /**
4145          * Get a tree of parent categories
4146          *
4147          * @param array $children Array with the children in the keys, to check for circular refs
4148          * @return array Tree of parent categories
4149          */
4150         public function getParentCategoryTree( $children = array() ) {
4151                 $stack = array();
4152                 $parents = $this->getParentCategories();
4153
4154                 if ( $parents ) {
4155                         foreach ( $parents as $parent => $current ) {
4156                                 if ( array_key_exists( $parent, $children ) ) {
4157                                         # Circular reference
4158                                         $stack[$parent] = array();
4159                                 } else {
4160                                         $nt = Title::newFromText( $parent );
4161                                         if ( $nt ) {
4162                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4163                                         }
4164                                 }
4165                         }
4166                 }
4167
4168                 return $stack;
4169         }
4170
4171         /**
4172          * Get an associative array for selecting this title from
4173          * the "page" table
4174          *
4175          * @return array Array suitable for the $where parameter of DB::select()
4176          */
4177         public function pageCond() {
4178                 if ( $this->mArticleID > 0 ) {
4179                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4180                         return array( 'page_id' => $this->mArticleID );
4181                 } else {
4182                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4183                 }
4184         }
4185
4186         /**
4187          * Get the revision ID of the previous revision
4188          *
4189          * @param int $revId Revision ID. Get the revision that was before this one.
4190          * @param int $flags Title::GAID_FOR_UPDATE
4191          * @return int|bool Old revision ID, or false if none exists
4192          */
4193         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4194                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4195                 $revId = $db->selectField( 'revision', 'rev_id',
4196                         array(
4197                                 'rev_page' => $this->getArticleID( $flags ),
4198                                 'rev_id < ' . intval( $revId )
4199                         ),
4200                         __METHOD__,
4201                         array( 'ORDER BY' => 'rev_id DESC' )
4202                 );
4203
4204                 if ( $revId === false ) {
4205                         return false;
4206                 } else {
4207                         return intval( $revId );
4208                 }
4209         }
4210
4211         /**
4212          * Get the revision ID of the next revision
4213          *
4214          * @param int $revId Revision ID. Get the revision that was after this one.
4215          * @param int $flags Title::GAID_FOR_UPDATE
4216          * @return int|bool Next revision ID, or false if none exists
4217          */
4218         public function getNextRevisionID( $revId, $flags = 0 ) {
4219                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4220                 $revId = $db->selectField( 'revision', 'rev_id',
4221                         array(
4222                                 'rev_page' => $this->getArticleID( $flags ),
4223                                 'rev_id > ' . intval( $revId )
4224                         ),
4225                         __METHOD__,
4226                         array( 'ORDER BY' => 'rev_id' )
4227                 );
4228
4229                 if ( $revId === false ) {
4230                         return false;
4231                 } else {
4232                         return intval( $revId );
4233                 }
4234         }
4235
4236         /**
4237          * Get the first revision of the page
4238          *
4239          * @param int $flags Title::GAID_FOR_UPDATE
4240          * @return Revision|null If page doesn't exist
4241          */
4242         public function getFirstRevision( $flags = 0 ) {
4243                 $pageId = $this->getArticleID( $flags );
4244                 if ( $pageId ) {
4245                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4246                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4247                                 array( 'rev_page' => $pageId ),
4248                                 __METHOD__,
4249                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4250                         );
4251                         if ( $row ) {
4252                                 return new Revision( $row );
4253                         }
4254                 }
4255                 return null;
4256         }
4257
4258         /**
4259          * Get the oldest revision timestamp of this page
4260          *
4261          * @param int $flags Title::GAID_FOR_UPDATE
4262          * @return string MW timestamp
4263          */
4264         public function getEarliestRevTime( $flags = 0 ) {
4265                 $rev = $this->getFirstRevision( $flags );
4266                 return $rev ? $rev->getTimestamp() : null;
4267         }
4268
4269         /**
4270          * Check if this is a new page
4271          *
4272          * @return bool
4273          */
4274         public function isNewPage() {
4275                 $dbr = wfGetDB( DB_SLAVE );
4276                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4277         }
4278
4279         /**
4280          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4281          *
4282          * @return bool
4283          */
4284         public function isBigDeletion() {
4285                 global $wgDeleteRevisionsLimit;
4286
4287                 if ( !$wgDeleteRevisionsLimit ) {
4288                         return false;
4289                 }
4290
4291                 $revCount = $this->estimateRevisionCount();
4292                 return $revCount > $wgDeleteRevisionsLimit;
4293         }
4294
4295         /**
4296          * Get the  approximate revision count of this page.
4297          *
4298          * @return int
4299          */
4300         public function estimateRevisionCount() {
4301                 if ( !$this->exists() ) {
4302                         return 0;
4303                 }
4304
4305                 if ( $this->mEstimateRevisions === null ) {
4306                         $dbr = wfGetDB( DB_SLAVE );
4307                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4308                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4309                 }
4310
4311                 return $this->mEstimateRevisions;
4312         }
4313
4314         /**
4315          * Get the number of revisions between the given revision.
4316          * Used for diffs and other things that really need it.
4317          *
4318          * @param int|Revision $old Old revision or rev ID (first before range)
4319          * @param int|Revision $new New revision or rev ID (first after range)
4320          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4321          * @return int Number of revisions between these revisions.
4322          */
4323         public function countRevisionsBetween( $old, $new, $max = null ) {
4324                 if ( !( $old instanceof Revision ) ) {
4325                         $old = Revision::newFromTitle( $this, (int)$old );
4326                 }
4327                 if ( !( $new instanceof Revision ) ) {
4328                         $new = Revision::newFromTitle( $this, (int)$new );
4329                 }
4330                 if ( !$old || !$new ) {
4331                         return 0; // nothing to compare
4332                 }
4333                 $dbr = wfGetDB( DB_SLAVE );
4334                 $conds = array(
4335                         'rev_page' => $this->getArticleID(),
4336                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4337                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4338                 );
4339                 if ( $max !== null ) {
4340                         $res = $dbr->select( 'revision', '1',
4341                                 $conds,
4342                                 __METHOD__,
4343                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4344                         );
4345                         return $res->numRows();
4346                 } else {
4347                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4348                 }
4349         }
4350
4351         /**
4352          * Get the authors between the given revisions or revision IDs.
4353          * Used for diffs and other things that really need it.
4354          *
4355          * @since 1.23
4356          *
4357          * @param int|Revision $old Old revision or rev ID (first before range by default)
4358          * @param int|Revision $new New revision or rev ID (first after range by default)
4359          * @param int $limit Maximum number of authors
4360          * @param string|array $options (Optional): Single option, or an array of options:
4361          *     'include_old' Include $old in the range; $new is excluded.
4362          *     'include_new' Include $new in the range; $old is excluded.
4363          *     'include_both' Include both $old and $new in the range.
4364          *     Unknown option values are ignored.
4365          * @return array|null Names of revision authors in the range; null if not both revisions exist
4366          */
4367         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4368                 if ( !( $old instanceof Revision ) ) {
4369                         $old = Revision::newFromTitle( $this, (int)$old );
4370                 }
4371                 if ( !( $new instanceof Revision ) ) {
4372                         $new = Revision::newFromTitle( $this, (int)$new );
4373                 }
4374                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4375                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4376                 // in the sanity check below?
4377                 if ( !$old || !$new ) {
4378                         return null; // nothing to compare
4379                 }
4380                 $authors = array();
4381                 $old_cmp = '>';
4382                 $new_cmp = '<';
4383                 $options = (array)$options;
4384                 if ( in_array( 'include_old', $options ) ) {
4385                         $old_cmp = '>=';
4386                 }
4387                 if ( in_array( 'include_new', $options ) ) {
4388                         $new_cmp = '<=';
4389                 }
4390                 if ( in_array( 'include_both', $options ) ) {
4391                         $old_cmp = '>=';
4392                         $new_cmp = '<=';
4393                 }
4394                 // No DB query needed if $old and $new are the same or successive revisions:
4395                 if ( $old->getId() === $new->getId() ) {
4396                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? array() : array( $old->getRawUserText() );
4397                 } elseif ( $old->getId() === $new->getParentId() ) {
4398                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4399                                 $authors[] = $old->getRawUserText();
4400                                 if ( $old->getRawUserText() != $new->getRawUserText() ) {
4401                                         $authors[] = $new->getRawUserText();
4402                                 }
4403                         } elseif ( $old_cmp === '>=' ) {
4404                                 $authors[] = $old->getRawUserText();
4405                         } elseif ( $new_cmp === '<=' ) {
4406                                 $authors[] = $new->getRawUserText();
4407                         }
4408                         return $authors;
4409                 }
4410                 $dbr = wfGetDB( DB_SLAVE );
4411                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4412                         array(
4413                                 'rev_page' => $this->getArticleID(),
4414                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4415                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4416                         ), __METHOD__,
4417                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4418                 );
4419                 foreach ( $res as $row ) {
4420                         $authors[] = $row->rev_user_text;
4421                 }
4422                 return $authors;
4423         }
4424
4425         /**
4426          * Get the number of authors between the given revisions or revision IDs.
4427          * Used for diffs and other things that really need it.
4428          *
4429          * @param int|Revision $old Old revision or rev ID (first before range by default)
4430          * @param int|Revision $new New revision or rev ID (first after range by default)
4431          * @param int $limit Maximum number of authors
4432          * @param string|array $options (Optional): Single option, or an array of options:
4433          *     'include_old' Include $old in the range; $new is excluded.
4434          *     'include_new' Include $new in the range; $old is excluded.
4435          *     'include_both' Include both $old and $new in the range.
4436          *     Unknown option values are ignored.
4437          * @return int Number of revision authors in the range; zero if not both revisions exist
4438          */
4439         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4440                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4441                 return $authors ? count( $authors ) : 0;
4442         }
4443
4444         /**
4445          * Compare with another title.
4446          *
4447          * @param Title $title
4448          * @return bool
4449          */
4450         public function equals( Title $title ) {
4451                 // Note: === is necessary for proper matching of number-like titles.
4452                 return $this->getInterwiki() === $title->getInterwiki()
4453                         && $this->getNamespace() == $title->getNamespace()
4454                         && $this->getDBkey() === $title->getDBkey();
4455         }
4456
4457         /**
4458          * Check if this title is a subpage of another title
4459          *
4460          * @param Title $title
4461          * @return bool
4462          */
4463         public function isSubpageOf( Title $title ) {
4464                 return $this->getInterwiki() === $title->getInterwiki()
4465                         && $this->getNamespace() == $title->getNamespace()
4466                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4467         }
4468
4469         /**
4470          * Check if page exists.  For historical reasons, this function simply
4471          * checks for the existence of the title in the page table, and will
4472          * thus return false for interwiki links, special pages and the like.
4473          * If you want to know if a title can be meaningfully viewed, you should
4474          * probably call the isKnown() method instead.
4475          *
4476          * @return bool
4477          */
4478         public function exists() {
4479                 return $this->getArticleID() != 0;
4480         }
4481
4482         /**
4483          * Should links to this title be shown as potentially viewable (i.e. as
4484          * "bluelinks"), even if there's no record by this title in the page
4485          * table?
4486          *
4487          * This function is semi-deprecated for public use, as well as somewhat
4488          * misleadingly named.  You probably just want to call isKnown(), which
4489          * calls this function internally.
4490          *
4491          * (ISSUE: Most of these checks are cheap, but the file existence check
4492          * can potentially be quite expensive.  Including it here fixes a lot of
4493          * existing code, but we might want to add an optional parameter to skip
4494          * it and any other expensive checks.)
4495          *
4496          * @return bool
4497          */
4498         public function isAlwaysKnown() {
4499                 $isKnown = null;
4500
4501                 /**
4502                  * Allows overriding default behavior for determining if a page exists.
4503                  * If $isKnown is kept as null, regular checks happen. If it's
4504                  * a boolean, this value is returned by the isKnown method.
4505                  *
4506                  * @since 1.20
4507                  *
4508                  * @param Title $title
4509                  * @param bool|null $isKnown
4510                  */
4511                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4512
4513                 if ( !is_null( $isKnown ) ) {
4514                         return $isKnown;
4515                 }
4516
4517                 if ( $this->isExternal() ) {
4518                         return true;  // any interwiki link might be viewable, for all we know
4519                 }
4520
4521                 switch ( $this->mNamespace ) {
4522                         case NS_MEDIA:
4523                         case NS_FILE:
4524                                 // file exists, possibly in a foreign repo
4525                                 return (bool)wfFindFile( $this );
4526                         case NS_SPECIAL:
4527                                 // valid special page
4528                                 return SpecialPageFactory::exists( $this->getDBkey() );
4529                         case NS_MAIN:
4530                                 // selflink, possibly with fragment
4531                                 return $this->mDbkeyform == '';
4532                         case NS_MEDIAWIKI:
4533                                 // known system message
4534                                 return $this->hasSourceText() !== false;
4535                         default:
4536                                 return false;
4537                 }
4538         }
4539
4540         /**
4541          * Does this title refer to a page that can (or might) be meaningfully
4542          * viewed?  In particular, this function may be used to determine if
4543          * links to the title should be rendered as "bluelinks" (as opposed to
4544          * "redlinks" to non-existent pages).
4545          * Adding something else to this function will cause inconsistency
4546          * since LinkHolderArray calls isAlwaysKnown() and does its own
4547          * page existence check.
4548          *
4549          * @return bool
4550          */
4551         public function isKnown() {
4552                 return $this->isAlwaysKnown() || $this->exists();
4553         }
4554
4555         /**
4556          * Does this page have source text?
4557          *
4558          * @return bool
4559          */
4560         public function hasSourceText() {
4561                 if ( $this->exists() ) {
4562                         return true;
4563                 }
4564
4565                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4566                         // If the page doesn't exist but is a known system message, default
4567                         // message content will be displayed, same for language subpages-
4568                         // Use always content language to avoid loading hundreds of languages
4569                         // to get the link color.
4570                         global $wgContLang;
4571                         list( $name, ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4572                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4573                         return $message->exists();
4574                 }
4575
4576                 return false;
4577         }
4578
4579         /**
4580          * Get the default message text or false if the message doesn't exist
4581          *
4582          * @return string|bool
4583          */
4584         public function getDefaultMessageText() {
4585                 global $wgContLang;
4586
4587                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4588                         return false;
4589                 }
4590
4591                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4592                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4593
4594                 if ( $message->exists() ) {
4595                         return $message->plain();
4596                 } else {
4597                         return false;
4598                 }
4599         }
4600
4601         /**
4602          * Updates page_touched for this page; called from LinksUpdate.php
4603          *
4604          * @return bool True if the update succeeded
4605          */
4606         public function invalidateCache() {
4607                 if ( wfReadOnly() ) {
4608                         return false;
4609                 }
4610
4611                 $method = __METHOD__;
4612                 $dbw = wfGetDB( DB_MASTER );
4613                 $conds = $this->pageCond();
4614                 $dbw->onTransactionIdle( function() use ( $dbw, $conds, $method ) {
4615                         $dbw->update(
4616                                 'page',
4617                                 array( 'page_touched' => $dbw->timestamp() ),
4618                                 $conds,
4619                                 $method
4620                         );
4621                 } );
4622
4623                 return true;
4624         }
4625
4626         /**
4627          * Update page_touched timestamps and send squid purge messages for
4628          * pages linking to this title. May be sent to the job queue depending
4629          * on the number of links. Typically called on create and delete.
4630          */
4631         public function touchLinks() {
4632                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4633                 $u->doUpdate();
4634
4635                 if ( $this->getNamespace() == NS_CATEGORY ) {
4636                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4637                         $u->doUpdate();
4638                 }
4639         }
4640
4641         /**
4642          * Get the last touched timestamp
4643          *
4644          * @param DatabaseBase $db Optional db
4645          * @return string Last-touched timestamp
4646          */
4647         public function getTouched( $db = null ) {
4648                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4649                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4650                 return $touched;
4651         }
4652
4653         /**
4654          * Get the timestamp when this page was updated since the user last saw it.
4655          *
4656          * @param User $user
4657          * @return string|null
4658          */
4659         public function getNotificationTimestamp( $user = null ) {
4660                 global $wgUser, $wgShowUpdatedMarker;
4661                 // Assume current user if none given
4662                 if ( !$user ) {
4663                         $user = $wgUser;
4664                 }
4665                 // Check cache first
4666                 $uid = $user->getId();
4667                 // avoid isset here, as it'll return false for null entries
4668                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4669                         return $this->mNotificationTimestamp[$uid];
4670                 }
4671                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4672                         $this->mNotificationTimestamp[$uid] = false;
4673                         return $this->mNotificationTimestamp[$uid];
4674                 }
4675                 // Don't cache too much!
4676                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4677                         $this->mNotificationTimestamp = array();
4678                 }
4679                 $dbr = wfGetDB( DB_SLAVE );
4680                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4681                         'wl_notificationtimestamp',
4682                         array(
4683                                 'wl_user' => $user->getId(),
4684                                 'wl_namespace' => $this->getNamespace(),
4685                                 'wl_title' => $this->getDBkey(),
4686                         ),
4687                         __METHOD__
4688                 );
4689                 return $this->mNotificationTimestamp[$uid];
4690         }
4691
4692         /**
4693          * Generate strings used for xml 'id' names in monobook tabs
4694          *
4695          * @param string $prepend Defaults to 'nstab-'
4696          * @return string XML 'id' name
4697          */
4698         public function getNamespaceKey( $prepend = 'nstab-' ) {
4699                 global $wgContLang;
4700                 // Gets the subject namespace if this title
4701                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4702                 // Checks if canonical namespace name exists for namespace
4703                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4704                         // Uses canonical namespace name
4705                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4706                 } else {
4707                         // Uses text of namespace
4708                         $namespaceKey = $this->getSubjectNsText();
4709                 }
4710                 // Makes namespace key lowercase
4711                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4712                 // Uses main
4713                 if ( $namespaceKey == '' ) {
4714                         $namespaceKey = 'main';
4715                 }
4716                 // Changes file to image for backwards compatibility
4717                 if ( $namespaceKey == 'file' ) {
4718                         $namespaceKey = 'image';
4719                 }
4720                 return $prepend . $namespaceKey;
4721         }
4722
4723         /**
4724          * Get all extant redirects to this Title
4725          *
4726          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4727          * @return Title[] Array of Title redirects to this title
4728          */
4729         public function getRedirectsHere( $ns = null ) {
4730                 $redirs = array();
4731
4732                 $dbr = wfGetDB( DB_SLAVE );
4733                 $where = array(
4734                         'rd_namespace' => $this->getNamespace(),
4735                         'rd_title' => $this->getDBkey(),
4736                         'rd_from = page_id'
4737                 );
4738                 if ( $this->isExternal() ) {
4739                         $where['rd_interwiki'] = $this->getInterwiki();
4740                 } else {
4741                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4742                 }
4743                 if ( !is_null( $ns ) ) {
4744                         $where['page_namespace'] = $ns;
4745                 }
4746
4747                 $res = $dbr->select(
4748                         array( 'redirect', 'page' ),
4749                         array( 'page_namespace', 'page_title' ),
4750                         $where,
4751                         __METHOD__
4752                 );
4753
4754                 foreach ( $res as $row ) {
4755                         $redirs[] = self::newFromRow( $row );
4756                 }
4757                 return $redirs;
4758         }
4759
4760         /**
4761          * Check if this Title is a valid redirect target
4762          *
4763          * @return bool
4764          */
4765         public function isValidRedirectTarget() {
4766                 global $wgInvalidRedirectTargets;
4767
4768                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4769                 if ( $this->isSpecial( 'Userlogout' ) ) {
4770                         return false;
4771                 }
4772
4773                 foreach ( $wgInvalidRedirectTargets as $target ) {
4774                         if ( $this->isSpecial( $target ) ) {
4775                                 return false;
4776                         }
4777                 }
4778
4779                 return true;
4780         }
4781
4782         /**
4783          * Get a backlink cache object
4784          *
4785          * @return BacklinkCache
4786          */
4787         public function getBacklinkCache() {
4788                 return BacklinkCache::get( $this );
4789         }
4790
4791         /**
4792          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4793          *
4794          * @return bool
4795          */
4796         public function canUseNoindex() {
4797                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4798
4799                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4800                         ? $wgContentNamespaces
4801                         : $wgExemptFromUserRobotsControl;
4802
4803                 return !in_array( $this->mNamespace, $bannedNamespaces );
4804
4805         }
4806
4807         /**
4808          * Returns the raw sort key to be used for categories, with the specified
4809          * prefix.  This will be fed to Collation::getSortKey() to get a
4810          * binary sortkey that can be used for actual sorting.
4811          *
4812          * @param string $prefix The prefix to be used, specified using
4813          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4814          *   prefix.
4815          * @return string
4816          */
4817         public function getCategorySortkey( $prefix = '' ) {
4818                 $unprefixed = $this->getText();
4819
4820                 // Anything that uses this hook should only depend
4821                 // on the Title object passed in, and should probably
4822                 // tell the users to run updateCollations.php --force
4823                 // in order to re-sort existing category relations.
4824                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4825                 if ( $prefix !== '' ) {
4826                         # Separate with a line feed, so the unprefixed part is only used as
4827                         # a tiebreaker when two pages have the exact same prefix.
4828                         # In UCA, tab is the only character that can sort above LF
4829                         # so we strip both of them from the original prefix.
4830                         $prefix = strtr( $prefix, "\n\t", '  ' );
4831                         return "$prefix\n$unprefixed";
4832                 }
4833                 return $unprefixed;
4834         }
4835
4836         /**
4837          * Get the language in which the content of this page is written in
4838          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4839          * e.g. $wgLang (such as special pages, which are in the user language).
4840          *
4841          * @since 1.18
4842          * @return Language
4843          */
4844         public function getPageLanguage() {
4845                 global $wgLang, $wgLanguageCode;
4846                 wfProfileIn( __METHOD__ );
4847                 if ( $this->isSpecialPage() ) {
4848                         // special pages are in the user language
4849                         wfProfileOut( __METHOD__ );
4850                         return $wgLang;
4851                 }
4852
4853                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4854                         // Note that this may depend on user settings, so the cache should be only per-request.
4855                         // NOTE: ContentHandler::getPageLanguage() may need to load the content to determine the page language!
4856                         // Checking $wgLanguageCode hasn't changed for the benefit of unit tests.
4857                         $contentHandler = ContentHandler::getForTitle( $this );
4858                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4859                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4860                 } else {
4861                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4862                 }
4863                 wfProfileOut( __METHOD__ );
4864                 return $langObj;
4865         }
4866
4867         /**
4868          * Get the language in which the content of this page is written when
4869          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4870          * e.g. $wgLang (such as special pages, which are in the user language).
4871          *
4872          * @since 1.20
4873          * @return Language
4874          */
4875         public function getPageViewLanguage() {
4876                 global $wgLang;
4877
4878                 if ( $this->isSpecialPage() ) {
4879                         // If the user chooses a variant, the content is actually
4880                         // in a language whose code is the variant code.
4881                         $variant = $wgLang->getPreferredVariant();
4882                         if ( $wgLang->getCode() !== $variant ) {
4883                                 return Language::factory( $variant );
4884                         }
4885
4886                         return $wgLang;
4887                 }
4888
4889                 //NOTE: can't be cached persistently, depends on user settings
4890                 //NOTE: ContentHandler::getPageViewLanguage() may need to load the content to determine the page language!
4891                 $contentHandler = ContentHandler::getForTitle( $this );
4892                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4893                 return $pageLang;
4894         }
4895
4896         /**
4897          * Get a list of rendered edit notices for this page.
4898          *
4899          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4900          * they will already be wrapped in paragraphs.
4901          *
4902          * @since 1.21
4903          * @param int $oldid Revision ID that's being edited
4904          * @return array
4905          */
4906         public function getEditNotices( $oldid = 0 ) {
4907                 $notices = array();
4908
4909                 # Optional notices on a per-namespace and per-page basis
4910                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4911                 $editnotice_ns_message = wfMessage( $editnotice_ns );
4912                 if ( $editnotice_ns_message->exists() ) {
4913                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
4914                 }
4915                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4916                         $parts = explode( '/', $this->getDBkey() );
4917                         $editnotice_base = $editnotice_ns;
4918                         while ( count( $parts ) > 0 ) {
4919                                 $editnotice_base .= '-' . array_shift( $parts );
4920                                 $editnotice_base_msg = wfMessage( $editnotice_base );
4921                                 if ( $editnotice_base_msg->exists() ) {
4922                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
4923                                 }
4924                         }
4925                 } else {
4926                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
4927                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4928                         $editnoticeMsg = wfMessage( $editnoticeText );
4929                         if ( $editnoticeMsg->exists() ) {
4930                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
4931                         }
4932                 }
4933
4934                 wfRunHooks( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4935                 return $notices;
4936         }
4937 }