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