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 string Text form (spaces not underscores) of the main part */
  60         public $mTextform = '';
  61
  62         /** @var string URL-encoded form of the main part */
  63         public $mUrlform = '';
  64
  65         /** @var string Main part with underscores */
  66         public $mDbkeyform = '';
  67
  68         /** @var string Database key with the initial letter in the case specified by the user */
  69         protected $mUserCaseDBKey;
  70
  71         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  72         public $mNamespace = NS_MAIN;
  73
  74         /** @var string Interwiki prefix */
  75         public $mInterwiki = '';
  76
  77         /** @var string Title fragment (i.e. the bit after the #) */
  78         public $mFragment = '';
  79
  80         /** @var int Article ID, fetched from the link cache on demand */
  81         public $mArticleID = -1;
  82
  83         /** @var bool|int ID of most recent revision */
  84         protected $mLatestID = false;
  85
  86         /**
  87          * @var bool|string ID of the page's content model, i.e. one of the
  88          *   CONTENT_MODEL_XXX constants
  89          */
  90         public $mContentModel = false;
  91
  92         /** @var int Estimated number of revisions; null of not loaded */
  93         private $mEstimateRevisions;
  94
  95         /** @var array Array of groups allowed to edit this article */
  96         public $mRestrictions = array();
  97
  98         /** @var bool  */
  99         protected $mOldRestrictions = false;
 100
 101         /** @var bool Cascade restrictions on this page to included templates and images? */
 102         public $mCascadeRestriction;
 103
 104         /** Caching the results of getCascadeProtectionSources */
 105         public $mCascadingRestrictions;
 106
 107         /** @var array When do the restrictions on this page expire? */
 108         protected $mRestrictionsExpiry = array();
 109
 110         /** @var bool Are cascading restrictions in effect on this page? */
 111         protected $mHasCascadingRestrictions;
 112
 113         /** @var array Where are the cascading restrictions coming from on this page? */
 114         public $mCascadeSources;
 115
 116         /** @var bool Boolean for initialisation on demand */
 117         public $mRestrictionsLoaded = false;
 118
 119         /** @var string Text form including namespace/interwiki, initialised on demand */
 120         protected $mPrefixedText = null;
 121
 122         /** @var mixed Cached value for getTitleProtection (create protection) */
 123         public $mTitleProtection;
 124
 125         /**
 126          * @var int Namespace index when there is no namespace. Don't change the
 127          *   following default, NS_MAIN is hardcoded in several places. See bug 696.
 128          *   Zero except in {{transclusion}} tags.
 129          */
 130         public $mDefaultNamespace = NS_MAIN;
 131
 132         /**
 133          * @var bool Is $wgUser watching this page? null if unfilled, accessed
 134          * through userIsWatching()
 135          */
 136         protected $mWatched = null;
 137
 138         /** @var int The page length, 0 for special pages */
 139         protected $mLength = -1;
 140
 141         /** @var null Is the article at this title a redirect? */
 142         public $mRedirect = null;
 143
 144         /** @var array Associative array of user ID -> timestamp/false */
 145         private $mNotificationTimestamp = array();
 146
 147         /** @var bool Whether a page has any subpages */
 148         private $mHasSubpages;
 149
 150         /** @var bool The (string) language code of the page's language and content code. */
 151         private $mPageLanguage = false;
 152
 153         /** @var string The page language code from the database */
 154         private $mDbPageLanguage = null;
 155
 156         /** @var TitleValue A corresponding TitleValue object */
 157         private $mTitleValue = null;
 158         // @}
 159
 160         /**
 161          * B/C kludge: provide a TitleParser for use by Title.
 162          * Ideally, Title would have no methods that need this.
 163          * Avoid usage of this singleton by using TitleValue
 164          * and the associated services when possible.
 165          *
 166          * @return TitleParser
 167          */
 168         private static function getTitleParser() {
 169                 global $wgContLang, $wgLocalInterwikis;
 170
 171                 static $titleCodec = null;
 172                 static $titleCodecFingerprint = null;
 173
 174                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 175                 // make sure we are using the right one. To detect changes over the course
 176                 // of a request, we remember a fingerprint of the config used to create the
 177                 // codec singleton, and re-create it if the fingerprint doesn't match.
 178                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . join( '+', $wgLocalInterwikis );
 179
 180                 if ( $fingerprint !== $titleCodecFingerprint ) {
 181                         $titleCodec = null;
 182                 }
 183
 184                 if ( !$titleCodec ) {
 185                         $titleCodec = new MediaWikiTitleCodec(
 186                                 $wgContLang,
 187                                 GenderCache::singleton(),
 188                                 $wgLocalInterwikis
 189                         );
 190                         $titleCodecFingerprint = $fingerprint;
 191                 }
 192
 193                 return $titleCodec;
 194         }
 195
 196         /**
 197          * B/C kludge: provide a TitleParser for use by Title.
 198          * Ideally, Title would have no methods that need this.
 199          * Avoid usage of this singleton by using TitleValue
 200          * and the associated services when possible.
 201          *
 202          * @return TitleFormatter
 203          */
 204         private static function getTitleFormatter() {
 205                 //NOTE: we know that getTitleParser() returns a MediaWikiTitleCodec,
 206                 //      which implements TitleFormatter.
 207                 return self::getTitleParser();
 208         }
 209
 210         function __construct() {
 211         }
 212
 213         /**
 214          * Create a new Title from a prefixed DB key
 215          *
 216          * @param string $key The database key, which has underscores
 217          *      instead of spaces, possibly including namespace and
 218          *      interwiki prefixes
 219          * @return Title|null Title, or null on an error
 220          */
 221         public static function newFromDBkey( $key ) {
 222                 $t = new Title();
 223                 $t->mDbkeyform = $key;
 224                 if ( $t->secureAndSplit() ) {
 225                         return $t;
 226                 } else {
 227                         return null;
 228                 }
 229         }
 230
 231         /**
 232          * Create a new Title from a TitleValue
 233          *
 234          * @param TitleValue $titleValue Assumed to be safe.
 235          *
 236          * @return Title
 237          */
 238         public static function newFromTitleValue( TitleValue $titleValue ) {
 239                 return self::makeTitle(
 240                         $titleValue->getNamespace(),
 241                         $titleValue->getText(),
 242                         $titleValue->getFragment() );
 243         }
 244
 245         /**
 246          * Create a new Title from text, such as what one would find in a link. De-
 247          * codes any HTML entities in the text.
 248          *
 249          * @param string $text The link text; spaces, prefixes, and an
 250          *   initial ':' indicating the main namespace are accepted.
 251          * @param int $defaultNamespace The namespace to use if none is specified
 252          *   by a prefix.  If you want to force a specific namespace even if
 253          *   $text might begin with a namespace prefix, use makeTitle() or
 254          *   makeTitleSafe().
 255          * @throws MWException
 256          * @return Title|null Title or null on an error.
 257          */
 258         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 259                 if ( is_object( $text ) ) {
 260                         throw new MWException( 'Title::newFromText given an object' );
 261                 }
 262
 263                 $cache = self::getTitleCache();
 264
 265                 /**
 266                  * Wiki pages often contain multiple links to the same page.
 267                  * Title normalization and parsing can become expensive on
 268                  * pages with many links, so we can save a little time by
 269                  * caching them.
 270                  *
 271                  * In theory these are value objects and won't get changed...
 272                  */
 273                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 274                         return $cache->get( $text );
 275                 }
 276
 277                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 278                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 279
 280                 $t = new Title();
 281                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 282                 $t->mDefaultNamespace = intval( $defaultNamespace );
 283
 284                 if ( $t->secureAndSplit() ) {
 285                         if ( $defaultNamespace == NS_MAIN ) {
 286                                 $cache->set( $text, $t );
 287                         }
 288                         return $t;
 289                 } else {
 290                         return null;
 291                 }
 292         }
 293
 294         /**
 295          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 296          *
 297          * Example of wrong and broken code:
 298          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 299          *
 300          * Example of right code:
 301          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 302          *
 303          * Create a new Title from URL-encoded text. Ensures that
 304          * the given title's length does not exceed the maximum.
 305          *
 306          * @param string $url The title, as might be taken from a URL
 307          * @return Title|null The new object, or null on an error
 308          */
 309         public static function newFromURL( $url ) {
 310                 $t = new Title();
 311
 312                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 313                 # but some URLs used it as a space replacement and they still come
 314                 # from some external search tools.
 315                 if ( strpos( self::legalChars(), '+' ) === false ) {
 316                         $url = str_replace( '+', ' ', $url );
 317                 }
 318
 319                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 320                 if ( $t->secureAndSplit() ) {
 321                         return $t;
 322                 } else {
 323                         return null;
 324                 }
 325         }
 326
 327         /**
 328          * @return MapCacheLRU
 329          */
 330         private static function getTitleCache() {
 331                 if ( self::$titleCache == null ) {
 332                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 333                 }
 334                 return self::$titleCache;
 335         }
 336
 337         /**
 338          * Returns a list of fields that are to be selected for initializing Title
 339          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 340          * whether to include page_content_model.
 341          *
 342          * @return array
 343          */
 344         protected static function getSelectFields() {
 345                 global $wgContentHandlerUseDB;
 346
 347                 $fields = array(
 348                         'page_namespace', 'page_title', 'page_id',
 349                         'page_len', 'page_is_redirect', 'page_latest',
 350                 );
 351
 352                 if ( $wgContentHandlerUseDB ) {
 353                         $fields[] = 'page_content_model';
 354                 }
 355
 356                 return $fields;
 357         }
 358
 359         /**
 360          * Create a new Title from an article ID
 361          *
 362          * @param int $id The page_id corresponding to the Title to create
 363          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 364          * @return Title|null The new object, or null on an error
 365          */
 366         public static function newFromID( $id, $flags = 0 ) {
 367                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 368                 $row = $db->selectRow(
 369                         'page',
 370                         self::getSelectFields(),
 371                         array( 'page_id' => $id ),
 372                         __METHOD__
 373                 );
 374                 if ( $row !== false ) {
 375                         $title = Title::newFromRow( $row );
 376                 } else {
 377                         $title = null;
 378                 }
 379                 return $title;
 380         }
 381
 382         /**
 383          * Make an array of titles from an array of IDs
 384          *
 385          * @param int[] $ids Array of IDs
 386          * @return Title[] Array of Titles
 387          */
 388         public static function newFromIDs( $ids ) {
 389                 if ( !count( $ids ) ) {
 390                         return array();
 391                 }
 392                 $dbr = wfGetDB( DB_SLAVE );
 393
 394                 $res = $dbr->select(
 395                         'page',
 396                         self::getSelectFields(),
 397                         array( 'page_id' => $ids ),
 398                         __METHOD__
 399                 );
 400
 401                 $titles = array();
 402                 foreach ( $res as $row ) {
 403                         $titles[] = Title::newFromRow( $row );
 404                 }
 405                 return $titles;
 406         }
 407
 408         /**
 409          * Make a Title object from a DB row
 410          *
 411          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 412          * @return Title Corresponding Title
 413          */
 414         public static function newFromRow( $row ) {
 415                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 416                 $t->loadFromRow( $row );
 417                 return $t;
 418         }
 419
 420         /**
 421          * Load Title object fields from a DB row.
 422          * If false is given, the title will be treated as non-existing.
 423          *
 424          * @param stdClass|bool $row Database row
 425          */
 426         public function loadFromRow( $row ) {
 427                 if ( $row ) { // page found
 428                         if ( isset( $row->page_id ) ) {
 429                                 $this->mArticleID = (int)$row->page_id;
 430                         }
 431                         if ( isset( $row->page_len ) ) {
 432                                 $this->mLength = (int)$row->page_len;
 433                         }
 434                         if ( isset( $row->page_is_redirect ) ) {
 435                                 $this->mRedirect = (bool)$row->page_is_redirect;
 436                         }
 437                         if ( isset( $row->page_latest ) ) {
 438                                 $this->mLatestID = (int)$row->page_latest;
 439                         }
 440                         if ( isset( $row->page_content_model ) ) {
 441                                 $this->mContentModel = strval( $row->page_content_model );
 442                         } else {
 443                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 444                         }
 445                         if ( isset( $row->page_lang ) ) {
 446                                 $this->mDbPageLanguage = (string)$row->page_lang;
 447                         }
 448                 } else { // page not found
 449                         $this->mArticleID = 0;
 450                         $this->mLength = 0;
 451                         $this->mRedirect = false;
 452                         $this->mLatestID = 0;
 453                         $this->mContentModel = false; # initialized lazily in getContentModel()
 454                 }
 455         }
 456
 457         /**
 458          * Create a new Title from a namespace index and a DB key.
 459          * It's assumed that $ns and $title are *valid*, for instance when
 460          * they came directly from the database or a special page name.
 461          * For convenience, spaces are converted to underscores so that
 462          * eg user_text fields can be used directly.
 463          *
 464          * @param int $ns The namespace of the article
 465          * @param string $title The unprefixed database key form
 466          * @param string $fragment The link fragment (after the "#")
 467          * @param string $interwiki The interwiki prefix
 468          * @return Title The new object
 469          */
 470         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 471                 $t = new Title();
 472                 $t->mInterwiki = $interwiki;
 473                 $t->mFragment = $fragment;
 474                 $t->mNamespace = $ns = intval( $ns );
 475                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 476                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 477                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 478                 $t->mTextform = str_replace( '_', ' ', $title );
 479                 $t->mContentModel = false; # initialized lazily in getContentModel()
 480                 return $t;
 481         }
 482
 483         /**
 484          * Create a new Title from a namespace index and a DB key.
 485          * The parameters will be checked for validity, which is a bit slower
 486          * than makeTitle() but safer for user-provided data.
 487          *
 488          * @param int $ns The namespace of the article
 489          * @param string $title Database key form
 490          * @param string $fragment The link fragment (after the "#")
 491          * @param string $interwiki Interwiki prefix
 492          * @return Title The new object, or null on an error
 493          */
 494         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 495                 if ( !MWNamespace::exists( $ns ) ) {
 496                         return null;
 497                 }
 498
 499                 $t = new Title();
 500                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 501                 if ( $t->secureAndSplit() ) {
 502                         return $t;
 503                 } else {
 504                         return null;
 505                 }
 506         }
 507
 508         /**
 509          * Create a new Title for the Main Page
 510          *
 511          * @return Title The new object
 512          */
 513         public static function newMainPage() {
 514                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 515                 // Don't give fatal errors if the message is broken
 516                 if ( !$title ) {
 517                         $title = Title::newFromText( 'Main Page' );
 518                 }
 519                 return $title;
 520         }
 521
 522         /**
 523          * Extract a redirect destination from a string and return the
 524          * Title, or null if the text doesn't contain a valid redirect
 525          * This will only return the very next target, useful for
 526          * the redirect table and other checks that don't need full recursion
 527          *
 528          * @param string $text Text with possible redirect
 529          * @return Title The corresponding Title
 530          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 531          */
 532         public static function newFromRedirect( $text ) {
 533                 ContentHandler::deprecated( __METHOD__, '1.21' );
 534
 535                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 536                 return $content->getRedirectTarget();
 537         }
 538
 539         /**
 540          * Extract a redirect destination from a string and return the
 541          * Title, or null if the text doesn't contain a valid redirect
 542          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 543          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 544          *
 545          * @param string $text Text with possible redirect
 546          * @return Title
 547          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 548          */
 549         public static function newFromRedirectRecurse( $text ) {
 550                 ContentHandler::deprecated( __METHOD__, '1.21' );
 551
 552                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 553                 return $content->getUltimateRedirectTarget();
 554         }
 555
 556         /**
 557          * Extract a redirect destination from a string and return an
 558          * array of Titles, or null if the text doesn't contain a valid redirect
 559          * The last element in the array is the final destination after all redirects
 560          * have been resolved (up to $wgMaxRedirects times)
 561          *
 562          * @param string $text Text with possible redirect
 563          * @return Title[] Array of Titles, with the destination last
 564          * @deprecated since 1.21, use Content::getRedirectChain instead.
 565          */
 566         public static function newFromRedirectArray( $text ) {
 567                 ContentHandler::deprecated( __METHOD__, '1.21' );
 568
 569                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 570                 return $content->getRedirectChain();
 571         }
 572
 573         /**
 574          * Get the prefixed DB key associated with an ID
 575          *
 576          * @param int $id The page_id of the article
 577          * @return Title|null An object representing the article, or null if no such article was found
 578          */
 579         public static function nameOf( $id ) {
 580                 $dbr = wfGetDB( DB_SLAVE );
 581
 582                 $s = $dbr->selectRow(
 583                         'page',
 584                         array( 'page_namespace', 'page_title' ),
 585                         array( 'page_id' => $id ),
 586                         __METHOD__
 587                 );
 588                 if ( $s === false ) {
 589                         return null;
 590                 }
 591
 592                 $n = self::makeName( $s->page_namespace, $s->page_title );
 593                 return $n;
 594         }
 595
 596         /**
 597          * Get a regex character class describing the legal characters in a link
 598          *
 599          * @return string The list of characters, not delimited
 600          */
 601         public static function legalChars() {
 602                 global $wgLegalTitleChars;
 603                 return $wgLegalTitleChars;
 604         }
 605
 606         /**
 607          * Returns a simple regex that will match on characters and sequences invalid in titles.
 608          * Note that this doesn't pick up many things that could be wrong with titles, but that
 609          * replacing this regex with something valid will make many titles valid.
 610          *
 611          * @todo: move this into MediaWikiTitleCodec
 612          *
 613          * @return string Regex string
 614          */
 615         static function getTitleInvalidRegex() {
 616                 static $rxTc = false;
 617                 if ( !$rxTc ) {
 618                         # Matching titles will be held as illegal.
 619                         $rxTc = '/' .
 620                                 # Any character not allowed is forbidden...
 621                                 '[^' . self::legalChars() . ']' .
 622                                 # URL percent encoding sequences interfere with the ability
 623                                 # to round-trip titles -- you can't link to them consistently.
 624                                 '|%[0-9A-Fa-f]{2}' .
 625                                 # XML/HTML character references produce similar issues.
 626                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 627                                 '|&#[0-9]+;' .
 628                                 '|&#x[0-9A-Fa-f]+;' .
 629                                 '/S';
 630                 }
 631
 632                 return $rxTc;
 633         }
 634
 635         /**
 636          * Utility method for converting a character sequence from bytes to Unicode.
 637          *
 638          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 639          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 640          *
 641          * @param string $byteClass
 642          * @return string
 643          */
 644         public static function convertByteClassToUnicodeClass( $byteClass ) {
 645                 $length = strlen( $byteClass );
 646                 // Input token queue
 647                 $x0 = $x1 = $x2 = '';
 648                 // Decoded queue
 649                 $d0 = $d1 = $d2 = '';
 650                 // Decoded integer codepoints
 651                 $ord0 = $ord1 = $ord2 = 0;
 652                 // Re-encoded queue
 653                 $r0 = $r1 = $r2 = '';
 654                 // Output
 655                 $out = '';
 656                 // Flags
 657                 $allowUnicode = false;
 658                 for ( $pos = 0; $pos < $length; $pos++ ) {
 659                         // Shift the queues down
 660                         $x2 = $x1;
 661                         $x1 = $x0;
 662                         $d2 = $d1;
 663                         $d1 = $d0;
 664                         $ord2 = $ord1;
 665                         $ord1 = $ord0;
 666                         $r2 = $r1;
 667                         $r1 = $r0;
 668                         // Load the current input token and decoded values
 669                         $inChar = $byteClass[$pos];
 670                         if ( $inChar == '\\' ) {
 671                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 672                                         $x0 = $inChar . $m[0];
 673                                         $d0 = chr( hexdec( $m[1] ) );
 674                                         $pos += strlen( $m[0] );
 675                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 676                                         $x0 = $inChar . $m[0];
 677                                         $d0 = chr( octdec( $m[0] ) );
 678                                         $pos += strlen( $m[0] );
 679                                 } elseif ( $pos + 1 >= $length ) {
 680                                         $x0 = $d0 = '\\';
 681                                 } else {
 682                                         $d0 = $byteClass[$pos + 1];
 683                                         $x0 = $inChar . $d0;
 684                                         $pos += 1;
 685                                 }
 686                         } else {
 687                                 $x0 = $d0 = $inChar;
 688                         }
 689                         $ord0 = ord( $d0 );
 690                         // Load the current re-encoded value
 691                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 692                                 $r0 = sprintf( '\x%02x', $ord0 );
 693                         } elseif ( $ord0 >= 0x80 ) {
 694                                 // Allow unicode if a single high-bit character appears
 695                                 $r0 = sprintf( '\x%02x', $ord0 );
 696                                 $allowUnicode = true;
 697                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 698                                 $r0 = '\\' . $d0;
 699                         } else {
 700                                 $r0 = $d0;
 701                         }
 702                         // Do the output
 703                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 704                                 // Range
 705                                 if ( $ord2 > $ord0 ) {
 706                                         // Empty range
 707                                 } elseif ( $ord0 >= 0x80 ) {
 708                                         // Unicode range
 709                                         $allowUnicode = true;
 710                                         if ( $ord2 < 0x80 ) {
 711                                                 // Keep the non-unicode section of the range
 712                                                 $out .= "$r2-\\x7F";
 713                                         }
 714                                 } else {
 715                                         // Normal range
 716                                         $out .= "$r2-$r0";
 717                                 }
 718                                 // Reset state to the initial value
 719                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 720                         } elseif ( $ord2 < 0x80 ) {
 721                                 // ASCII character
 722                                 $out .= $r2;
 723                         }
 724                 }
 725                 if ( $ord1 < 0x80 ) {
 726                         $out .= $r1;
 727                 }
 728                 if ( $ord0 < 0x80 ) {
 729                         $out .= $r0;
 730                 }
 731                 if ( $allowUnicode ) {
 732                         $out .= '\u0080-\uFFFF';
 733                 }
 734                 return $out;
 735         }
 736
 737         /**
 738          * Make a prefixed DB key from a DB key and a namespace index
 739          *
 740          * @param int $ns Numerical representation of the namespace
 741          * @param string $title The DB key form the title
 742          * @param string $fragment The link fragment (after the "#")
 743          * @param string $interwiki The interwiki prefix
 744          * @return string The prefixed form of the title
 745          */
 746         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 747                 global $wgContLang;
 748
 749                 $namespace = $wgContLang->getNsText( $ns );
 750                 $name = $namespace == '' ? $title : "$namespace:$title";
 751                 if ( strval( $interwiki ) != '' ) {
 752                         $name = "$interwiki:$name";
 753                 }
 754                 if ( strval( $fragment ) != '' ) {
 755                         $name .= '#' . $fragment;
 756                 }
 757                 return $name;
 758         }
 759
 760         /**
 761          * Escape a text fragment, say from a link, for a URL
 762          *
 763          * @param string $fragment Containing a URL or link fragment (after the "#")
 764          * @return string Escaped string
 765          */
 766         static function escapeFragmentForURL( $fragment ) {
 767                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 768                 # fragments appear not to work in IE (at least up to 7) or in at least
 769                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 770                 # to care if they aren't encoded.
 771                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 772         }
 773
 774         /**
 775          * Callback for usort() to do title sorts by (namespace, title)
 776          *
 777          * @param Title $a
 778          * @param Title $b
 779          *
 780          * @return int Result of string comparison, or namespace comparison
 781          */
 782         public static function compare( $a, $b ) {
 783                 if ( $a->getNamespace() == $b->getNamespace() ) {
 784                         return strcmp( $a->getText(), $b->getText() );
 785                 } else {
 786                         return $a->getNamespace() - $b->getNamespace();
 787                 }
 788         }
 789
 790         /**
 791          * Determine whether the object refers to a page within
 792          * this project.
 793          *
 794          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 795          */
 796         public function isLocal() {
 797                 if ( $this->isExternal() ) {
 798                         $iw = Interwiki::fetch( $this->mInterwiki );
 799                         if ( $iw ) {
 800                                 return $iw->isLocal();
 801                         }
 802                 }
 803                 return true;
 804         }
 805
 806         /**
 807          * Is this Title interwiki?
 808          *
 809          * @return bool
 810          */
 811         public function isExternal() {
 812                 return $this->mInterwiki !== '';
 813         }
 814
 815         /**
 816          * Get the interwiki prefix
 817          *
 818          * Use Title::isExternal to check if a interwiki is set
 819          *
 820          * @return string Interwiki prefix
 821          */
 822         public function getInterwiki() {
 823                 return $this->mInterwiki;
 824         }
 825
 826         /**
 827          * Determine whether the object refers to a page within
 828          * this project and is transcludable.
 829          *
 830          * @return bool True if this is transcludable
 831          */
 832         public function isTrans() {
 833                 if ( !$this->isExternal() ) {
 834                         return false;
 835                 }
 836
 837                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 838         }
 839
 840         /**
 841          * Returns the DB name of the distant wiki which owns the object.
 842          *
 843          * @return string The DB name
 844          */
 845         public function getTransWikiID() {
 846                 if ( !$this->isExternal() ) {
 847                         return false;
 848                 }
 849
 850                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 851         }
 852
 853         /**
 854          * Get a TitleValue object representing this Title.
 855          *
 856          * @note: Not all valid Titles have a corresponding valid TitleValue
 857          * (e.g. TitleValues cannot represent page-local links that have a
 858          * fragment but no title text).
 859          *
 860          * @return TitleValue|null
 861          */
 862         public function getTitleValue() {
 863                 if ( $this->mTitleValue === null ) {
 864                         try {
 865                                 $this->mTitleValue = new TitleValue(
 866                                         $this->getNamespace(),
 867                                         $this->getDBkey(),
 868                                         $this->getFragment() );
 869                         } catch ( InvalidArgumentException $ex ) {
 870                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 871                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 872                         }
 873                 }
 874
 875                 return $this->mTitleValue;
 876         }
 877
 878         /**
 879          * Get the text form (spaces not underscores) of the main part
 880          *
 881          * @return string Main part of the title
 882          */
 883         public function getText() {
 884                 return $this->mTextform;
 885         }
 886
 887         /**
 888          * Get the URL-encoded form of the main part
 889          *
 890          * @return string Main part of the title, URL-encoded
 891          */
 892         public function getPartialURL() {
 893                 return $this->mUrlform;
 894         }
 895
 896         /**
 897          * Get the main part with underscores
 898          *
 899          * @return string Main part of the title, with underscores
 900          */
 901         public function getDBkey() {
 902                 return $this->mDbkeyform;
 903         }
 904
 905         /**
 906          * Get the DB key with the initial letter case as specified by the user
 907          *
 908          * @return string DB key
 909          */
 910         function getUserCaseDBKey() {
 911                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 912                         return $this->mUserCaseDBKey;
 913                 } else {
 914                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 915                         return $this->mDbkeyform;
 916                 }
 917         }
 918
 919         /**
 920          * Get the namespace index, i.e. one of the NS_xxxx constants.
 921          *
 922          * @return int Namespace index
 923          */
 924         public function getNamespace() {
 925                 return $this->mNamespace;
 926         }
 927
 928         /**
 929          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 930          *
 931          * @throws MWException
 932          * @return string Content model id
 933          */
 934         public function getContentModel() {
 935                 if ( !$this->mContentModel ) {
 936                         $linkCache = LinkCache::singleton();
 937                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 938                 }
 939
 940                 if ( !$this->mContentModel ) {
 941                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 942                 }
 943
 944                 if ( !$this->mContentModel ) {
 945                         throw new MWException( 'Failed to determine content model!' );
 946                 }
 947
 948                 return $this->mContentModel;
 949         }
 950
 951         /**
 952          * Convenience method for checking a title's content model name
 953          *
 954          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 955          * @return bool True if $this->getContentModel() == $id
 956          */
 957         public function hasContentModel( $id ) {
 958                 return $this->getContentModel() == $id;
 959         }
 960
 961         /**
 962          * Get the namespace text
 963          *
 964          * @return string Namespace text
 965          */
 966         public function getNsText() {
 967                 if ( $this->isExternal() ) {
 968                         // This probably shouldn't even happen. ohh man, oh yuck.
 969                         // But for interwiki transclusion it sometimes does.
 970                         // Shit. Shit shit shit.
 971                         //
 972                         // Use the canonical namespaces if possible to try to
 973                         // resolve a foreign namespace.
 974                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 975                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 976                         }
 977                 }
 978
 979                 try {
 980                         $formatter = $this->getTitleFormatter();
 981                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 982                 } catch ( InvalidArgumentException $ex )  {
 983                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 984                         return false;
 985                 }
 986         }
 987
 988         /**
 989          * Get the namespace text of the subject (rather than talk) page
 990          *
 991          * @return string Namespace text
 992          */
 993         public function getSubjectNsText() {
 994                 global $wgContLang;
 995                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 996         }
 997
 998         /**
 999          * Get the namespace text of the talk page
1000          *
1001          * @return string Namespace text
1002          */
1003         public function getTalkNsText() {
1004                 global $wgContLang;
1005                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1006         }
1007
1008         /**
1009          * Could this title have a corresponding talk page?
1010          *
1011          * @return bool
1012          */
1013         public function canTalk() {
1014                 return MWNamespace::canTalk( $this->mNamespace );
1015         }
1016
1017         /**
1018          * Is this in a namespace that allows actual pages?
1019          *
1020          * @return bool
1021          * @internal note -- uses hardcoded namespace index instead of constants
1022          */
1023         public function canExist() {
1024                 return $this->mNamespace >= NS_MAIN;
1025         }
1026
1027         /**
1028          * Can this title be added to a user's watchlist?
1029          *
1030          * @return bool
1031          */
1032         public function isWatchable() {
1033                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1034         }
1035
1036         /**
1037          * Returns true if this is a special page.
1038          *
1039          * @return bool
1040          */
1041         public function isSpecialPage() {
1042                 return $this->getNamespace() == NS_SPECIAL;
1043         }
1044
1045         /**
1046          * Returns true if this title resolves to the named special page
1047          *
1048          * @param string $name The special page name
1049          * @return bool
1050          */
1051         public function isSpecial( $name ) {
1052                 if ( $this->isSpecialPage() ) {
1053                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1054                         if ( $name == $thisName ) {
1055                                 return true;
1056                         }
1057                 }
1058                 return false;
1059         }
1060
1061         /**
1062          * If the Title refers to a special page alias which is not the local default, resolve
1063          * the alias, and localise the name as necessary.  Otherwise, return $this
1064          *
1065          * @return Title
1066          */
1067         public function fixSpecialName() {
1068                 if ( $this->isSpecialPage() ) {
1069                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1070                         if ( $canonicalName ) {
1071                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1072                                 if ( $localName != $this->mDbkeyform ) {
1073                                         return Title::makeTitle( NS_SPECIAL, $localName );
1074                                 }
1075                         }
1076                 }
1077                 return $this;
1078         }
1079
1080         /**
1081          * Returns true if the title is inside the specified namespace.
1082          *
1083          * Please make use of this instead of comparing to getNamespace()
1084          * This function is much more resistant to changes we may make
1085          * to namespaces than code that makes direct comparisons.
1086          * @param int $ns The namespace
1087          * @return bool
1088          * @since 1.19
1089          */
1090         public function inNamespace( $ns ) {
1091                 return MWNamespace::equals( $this->getNamespace(), $ns );
1092         }
1093
1094         /**
1095          * Returns true if the title is inside one of the specified namespaces.
1096          *
1097          * @param ...$namespaces The namespaces to check for
1098          * @return bool
1099          * @since 1.19
1100          */
1101         public function inNamespaces( /* ... */ ) {
1102                 $namespaces = func_get_args();
1103                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1104                         $namespaces = $namespaces[0];
1105                 }
1106
1107                 foreach ( $namespaces as $ns ) {
1108                         if ( $this->inNamespace( $ns ) ) {
1109                                 return true;
1110                         }
1111                 }
1112
1113                 return false;
1114         }
1115
1116         /**
1117          * Returns true if the title has the same subject namespace as the
1118          * namespace specified.
1119          * For example this method will take NS_USER and return true if namespace
1120          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1121          * as their subject namespace.
1122          *
1123          * This is MUCH simpler than individually testing for equivalence
1124          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1125          * @since 1.19
1126          * @param int $ns
1127          * @return bool
1128          */
1129         public function hasSubjectNamespace( $ns ) {
1130                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1131         }
1132
1133         /**
1134          * Is this Title in a namespace which contains content?
1135          * In other words, is this a content page, for the purposes of calculating
1136          * statistics, etc?
1137          *
1138          * @return bool
1139          */
1140         public function isContentPage() {
1141                 return MWNamespace::isContent( $this->getNamespace() );
1142         }
1143
1144         /**
1145          * Would anybody with sufficient privileges be able to move this page?
1146          * Some pages just aren't movable.
1147          *
1148          * @return bool
1149          */
1150         public function isMovable() {
1151                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1152                         // Interwiki title or immovable namespace. Hooks don't get to override here
1153                         return false;
1154                 }
1155
1156                 $result = true;
1157                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1158                 return $result;
1159         }
1160
1161         /**
1162          * Is this the mainpage?
1163          * @note Title::newFromText seems to be sufficiently optimized by the title
1164          * cache that we don't need to over-optimize by doing direct comparisons and
1165          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1166          * ends up reporting something differently than $title->isMainPage();
1167          *
1168          * @since 1.18
1169          * @return bool
1170          */
1171         public function isMainPage() {
1172                 return $this->equals( Title::newMainPage() );
1173         }
1174
1175         /**
1176          * Is this a subpage?
1177          *
1178          * @return bool
1179          */
1180         public function isSubpage() {
1181                 return MWNamespace::hasSubpages( $this->mNamespace )
1182                         ? strpos( $this->getText(), '/' ) !== false
1183                         : false;
1184         }
1185
1186         /**
1187          * Is this a conversion table for the LanguageConverter?
1188          *
1189          * @return bool
1190          */
1191         public function isConversionTable() {
1192                 // @todo ConversionTable should become a separate content model.
1193
1194                 return $this->getNamespace() == NS_MEDIAWIKI &&
1195                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1196         }
1197
1198         /**
1199          * Does that page contain wikitext, or it is JS, CSS or whatever?
1200          *
1201          * @return bool
1202          */
1203         public function isWikitextPage() {
1204                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1205         }
1206
1207         /**
1208          * Could this page contain custom CSS or JavaScript for the global UI.
1209          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1210          * or CONTENT_MODEL_JAVASCRIPT.
1211          *
1212          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1213          * for that!
1214          *
1215          * Note that this method should not return true for pages that contain and
1216          * show "inactive" CSS or JS.
1217          *
1218          * @return bool
1219          */
1220         public function isCssOrJsPage() {
1221                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1222                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1223                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1224
1225                 # @note This hook is also called in ContentHandler::getDefaultModel.
1226                 #   It's called here again to make sure hook functions can force this
1227                 #   method to return true even outside the mediawiki namespace.
1228
1229                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
1230
1231                 return $isCssOrJsPage;
1232         }
1233
1234         /**
1235          * Is this a .css or .js subpage of a user page?
1236          * @return bool
1237          */
1238         public function isCssJsSubpage() {
1239                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1240                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1241                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1242         }
1243
1244         /**
1245          * Trim down a .css or .js subpage title to get the corresponding skin name
1246          *
1247          * @return string Containing skin name from .css or .js subpage title
1248          */
1249         public function getSkinFromCssJsSubpage() {
1250                 $subpage = explode( '/', $this->mTextform );
1251                 $subpage = $subpage[count( $subpage ) - 1];
1252                 $lastdot = strrpos( $subpage, '.' );
1253                 if ( $lastdot === false ) {
1254                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1255                 }
1256                 return substr( $subpage, 0, $lastdot );
1257         }
1258
1259         /**
1260          * Is this a .css subpage of a user page?
1261          *
1262          * @return bool
1263          */
1264         public function isCssSubpage() {
1265                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1266                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1267         }
1268
1269         /**
1270          * Is this a .js subpage of a user page?
1271          *
1272          * @return bool
1273          */
1274         public function isJsSubpage() {
1275                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1276                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1277         }
1278
1279         /**
1280          * Is this a talk page of some sort?
1281          *
1282          * @return bool
1283          */
1284         public function isTalkPage() {
1285                 return MWNamespace::isTalk( $this->getNamespace() );
1286         }
1287
1288         /**
1289          * Get a Title object associated with the talk page of this article
1290          *
1291          * @return Title The object for the talk page
1292          */
1293         public function getTalkPage() {
1294                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1295         }
1296
1297         /**
1298          * Get a title object associated with the subject page of this
1299          * talk page
1300          *
1301          * @return Title The object for the subject page
1302          */
1303         public function getSubjectPage() {
1304                 // Is this the same title?
1305                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1306                 if ( $this->getNamespace() == $subjectNS ) {
1307                         return $this;
1308                 }
1309                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1310         }
1311
1312         /**
1313          * Get the default namespace index, for when there is no namespace
1314          *
1315          * @return int Default namespace index
1316          */
1317         public function getDefaultNamespace() {
1318                 return $this->mDefaultNamespace;
1319         }
1320
1321         /**
1322          * Get the Title fragment (i.e.\ the bit after the #) in text form
1323          *
1324          * Use Title::hasFragment to check for a fragment
1325          *
1326          * @return string Title fragment
1327          */
1328         public function getFragment() {
1329                 return $this->mFragment;
1330         }
1331
1332         /**
1333          * Check if a Title fragment is set
1334          *
1335          * @return bool
1336          * @since 1.23
1337          */
1338         public function hasFragment() {
1339                 return $this->mFragment !== '';
1340         }
1341
1342         /**
1343          * Get the fragment in URL form, including the "#" character if there is one
1344          * @return string Fragment in URL form
1345          */
1346         public function getFragmentForURL() {
1347                 if ( !$this->hasFragment() ) {
1348                         return '';
1349                 } else {
1350                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1351                 }
1352         }
1353
1354         /**
1355          * Set the fragment for this title. Removes the first character from the
1356          * specified fragment before setting, so it assumes you're passing it with
1357          * an initial "#".
1358          *
1359          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1360          * Still in active use privately.
1361          *
1362          * @param string $fragment Text
1363          */
1364         public function setFragment( $fragment ) {
1365                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1366         }
1367
1368         /**
1369          * Prefix some arbitrary text with the namespace or interwiki prefix
1370          * of this object
1371          *
1372          * @param string $name The text
1373          * @return string The prefixed text
1374          */
1375         private function prefix( $name ) {
1376                 $p = '';
1377                 if ( $this->isExternal() ) {
1378                         $p = $this->mInterwiki . ':';
1379                 }
1380
1381                 if ( 0 != $this->mNamespace ) {
1382                         $p .= $this->getNsText() . ':';
1383                 }
1384                 return $p . $name;
1385         }
1386
1387         /**
1388          * Get the prefixed database key form
1389          *
1390          * @return string The prefixed title, with underscores and
1391          *  any interwiki and namespace prefixes
1392          */
1393         public function getPrefixedDBkey() {
1394                 $s = $this->prefix( $this->mDbkeyform );
1395                 $s = str_replace( ' ', '_', $s );
1396                 return $s;
1397         }
1398
1399         /**
1400          * Get the prefixed title with spaces.
1401          * This is the form usually used for display
1402          *
1403          * @return string The prefixed title, with spaces
1404          */
1405         public function getPrefixedText() {
1406                 if ( $this->mPrefixedText === null ) {
1407                         $s = $this->prefix( $this->mTextform );
1408                         $s = str_replace( '_', ' ', $s );
1409                         $this->mPrefixedText = $s;
1410                 }
1411                 return $this->mPrefixedText;
1412         }
1413
1414         /**
1415          * Return a string representation of this title
1416          *
1417          * @return string Representation of this title
1418          */
1419         public function __toString() {
1420                 return $this->getPrefixedText();
1421         }
1422
1423         /**
1424          * Get the prefixed title with spaces, plus any fragment
1425          * (part beginning with '#')
1426          *
1427          * @return string The prefixed title, with spaces and the fragment, including '#'
1428          */
1429         public function getFullText() {
1430                 $text = $this->getPrefixedText();
1431                 if ( $this->hasFragment() ) {
1432                         $text .= '#' . $this->getFragment();
1433                 }
1434                 return $text;
1435         }
1436
1437         /**
1438          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1439          *
1440          * @par Example:
1441          * @code
1442          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1443          * # returns: 'Foo'
1444          * @endcode
1445          *
1446          * @return string Root name
1447          * @since 1.20
1448          */
1449         public function getRootText() {
1450                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1451                         return $this->getText();
1452                 }
1453
1454                 return strtok( $this->getText(), '/' );
1455         }
1456
1457         /**
1458          * Get the root page name title, i.e. the leftmost part before any slashes
1459          *
1460          * @par Example:
1461          * @code
1462          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1463          * # returns: Title{User:Foo}
1464          * @endcode
1465          *
1466          * @return Title Root title
1467          * @since 1.20
1468          */
1469         public function getRootTitle() {
1470                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1471         }
1472
1473         /**
1474          * Get the base page name without a namespace, i.e. the part before the subpage name
1475          *
1476          * @par Example:
1477          * @code
1478          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1479          * # returns: 'Foo/Bar'
1480          * @endcode
1481          *
1482          * @return string Base name
1483          */
1484         public function getBaseText() {
1485                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1486                         return $this->getText();
1487                 }
1488
1489                 $parts = explode( '/', $this->getText() );
1490                 # Don't discard the real title if there's no subpage involved
1491                 if ( count( $parts ) > 1 ) {
1492                         unset( $parts[count( $parts ) - 1] );
1493                 }
1494                 return implode( '/', $parts );
1495         }
1496
1497         /**
1498          * Get the base page name title, i.e. the part before the subpage name
1499          *
1500          * @par Example:
1501          * @code
1502          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1503          * # returns: Title{User:Foo/Bar}
1504          * @endcode
1505          *
1506          * @return Title Base title
1507          * @since 1.20
1508          */
1509         public function getBaseTitle() {
1510                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1511         }
1512
1513         /**
1514          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1515          *
1516          * @par Example:
1517          * @code
1518          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1519          * # returns: "Baz"
1520          * @endcode
1521          *
1522          * @return string Subpage name
1523          */
1524         public function getSubpageText() {
1525                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1526                         return $this->mTextform;
1527                 }
1528                 $parts = explode( '/', $this->mTextform );
1529                 return $parts[count( $parts ) - 1];
1530         }
1531
1532         /**
1533          * Get the title for a subpage of the current page
1534          *
1535          * @par Example:
1536          * @code
1537          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1538          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1539          * @endcode
1540          *
1541          * @param string $text The subpage name to add to the title
1542          * @return Title Subpage title
1543          * @since 1.20
1544          */
1545         public function getSubpage( $text ) {
1546                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1547         }
1548
1549         /**
1550          * Get the HTML-escaped displayable text form.
1551          * Used for the title field in <a> tags.
1552          *
1553          * @return string The text, including any prefixes
1554          * @deprecated since 1.19
1555          */
1556         public function getEscapedText() {
1557                 wfDeprecated( __METHOD__, '1.19' );
1558                 return htmlspecialchars( $this->getPrefixedText() );
1559         }
1560
1561         /**
1562          * Get a URL-encoded form of the subpage text
1563          *
1564          * @return string URL-encoded subpage name
1565          */
1566         public function getSubpageUrlForm() {
1567                 $text = $this->getSubpageText();
1568                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1569                 return $text;
1570         }
1571
1572         /**
1573          * Get a URL-encoded title (not an actual URL) including interwiki
1574          *
1575          * @return string The URL-encoded form
1576          */
1577         public function getPrefixedURL() {
1578                 $s = $this->prefix( $this->mDbkeyform );
1579                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1580                 return $s;
1581         }
1582
1583         /**
1584          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1585          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1586          * second argument named variant. This was deprecated in favor
1587          * of passing an array of option with a "variant" key
1588          * Once $query2 is removed for good, this helper can be dropped
1589          * and the wfArrayToCgi moved to getLocalURL();
1590          *
1591          * @since 1.19 (r105919)
1592          * @param array|string $query
1593          * @param bool $query2
1594          * @return string
1595          */
1596         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1597                 if ( $query2 !== false ) {
1598                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1599                                 "method called with a second parameter is deprecated. Add your " .
1600                                 "parameter to an array passed as the first parameter.", "1.19" );
1601                 }
1602                 if ( is_array( $query ) ) {
1603                         $query = wfArrayToCgi( $query );
1604                 }
1605                 if ( $query2 ) {
1606                         if ( is_string( $query2 ) ) {
1607                                 // $query2 is a string, we will consider this to be
1608                                 // a deprecated $variant argument and add it to the query
1609                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1610                         } else {
1611                                 $query2 = wfArrayToCgi( $query2 );
1612                         }
1613                         // If we have $query content add a & to it first
1614                         if ( $query ) {
1615                                 $query .= '&';
1616                         }
1617                         // Now append the queries together
1618                         $query .= $query2;
1619                 }
1620                 return $query;
1621         }
1622
1623         /**
1624          * Get a real URL referring to this title, with interwiki link and
1625          * fragment
1626          *
1627          * @see self::getLocalURL for the arguments.
1628          * @see wfExpandUrl
1629          * @param array|string $query
1630          * @param bool $query2
1631          * @param string $proto Protocol type to use in URL
1632          * @return string The URL
1633          */
1634         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1635                 $query = self::fixUrlQueryArgs( $query, $query2 );
1636
1637                 # Hand off all the decisions on urls to getLocalURL
1638                 $url = $this->getLocalURL( $query );
1639
1640                 # Expand the url to make it a full url. Note that getLocalURL has the
1641                 # potential to output full urls for a variety of reasons, so we use
1642                 # wfExpandUrl instead of simply prepending $wgServer
1643                 $url = wfExpandUrl( $url, $proto );
1644
1645                 # Finally, add the fragment.
1646                 $url .= $this->getFragmentForURL();
1647
1648                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1649                 return $url;
1650         }
1651
1652         /**
1653          * Get a URL with no fragment or server name (relative URL) from a Title object.
1654          * If this page is generated with action=render, however,
1655          * $wgServer is prepended to make an absolute URL.
1656          *
1657          * @see self::getFullURL to always get an absolute URL.
1658          * @see self::newFromText to produce a Title object.
1659          *
1660          * @param string|array $query an optional query string,
1661          *   not used for interwiki links. Can be specified as an associative array as well,
1662          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1663          *   Some query patterns will trigger various shorturl path replacements.
1664          * @param array $query2 An optional secondary query array. This one MUST
1665          *   be an array. If a string is passed it will be interpreted as a deprecated
1666          *   variant argument and urlencoded into a variant= argument.
1667          *   This second query argument will be added to the $query
1668          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1669          *   pair in the first parameter array instead.
1670          *
1671          * @return string String of the URL.
1672          */
1673         public function getLocalURL( $query = '', $query2 = false ) {
1674                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1675
1676                 $query = self::fixUrlQueryArgs( $query, $query2 );
1677
1678                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1679                 if ( $interwiki ) {
1680                         $namespace = $this->getNsText();
1681                         if ( $namespace != '' ) {
1682                                 # Can this actually happen? Interwikis shouldn't be parsed.
1683                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1684                                 $namespace .= ':';
1685                         }
1686                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1687                         $url = wfAppendQuery( $url, $query );
1688                 } else {
1689                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1690                         if ( $query == '' ) {
1691                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1692                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1693                         } else {
1694                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1695                                 $url = false;
1696                                 $matches = array();
1697
1698                                 if ( !empty( $wgActionPaths )
1699                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1700                                 ) {
1701                                         $action = urldecode( $matches[2] );
1702                                         if ( isset( $wgActionPaths[$action] ) ) {
1703                                                 $query = $matches[1];
1704                                                 if ( isset( $matches[4] ) ) {
1705                                                         $query .= $matches[4];
1706                                                 }
1707                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1708                                                 if ( $query != '' ) {
1709                                                         $url = wfAppendQuery( $url, $query );
1710                                                 }
1711                                         }
1712                                 }
1713
1714                                 if ( $url === false
1715                                         && $wgVariantArticlePath
1716                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1717                                         && $this->getPageLanguage()->hasVariants()
1718                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1719                                 ) {
1720                                         $variant = urldecode( $matches[1] );
1721                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1722                                                 // Only do the variant replacement if the given variant is a valid
1723                                                 // variant for the page's language.
1724                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1725                                                 $url = str_replace( '$1', $dbkey, $url );
1726                                         }
1727                                 }
1728
1729                                 if ( $url === false ) {
1730                                         if ( $query == '-' ) {
1731                                                 $query = '';
1732                                         }
1733                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1734                                 }
1735                         }
1736
1737                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1738
1739                         // @todo FIXME: This causes breakage in various places when we
1740                         // actually expected a local URL and end up with dupe prefixes.
1741                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1742                                 $url = $wgServer . $url;
1743                         }
1744                 }
1745                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1746                 return $url;
1747         }
1748
1749         /**
1750          * Get a URL that's the simplest URL that will be valid to link, locally,
1751          * to the current Title.  It includes the fragment, but does not include
1752          * the server unless action=render is used (or the link is external).  If
1753          * there's a fragment but the prefixed text is empty, we just return a link
1754          * to the fragment.
1755          *
1756          * The result obviously should not be URL-escaped, but does need to be
1757          * HTML-escaped if it's being output in HTML.
1758          *
1759          * @param array $query
1760          * @param bool $query2
1761          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1762          * @see self::getLocalURL for the arguments.
1763          * @return string The URL
1764          */
1765         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1766                 wfProfileIn( __METHOD__ );
1767                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1768                         $ret = $this->getFullURL( $query, $query2, $proto );
1769                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1770                         $ret = $this->getFragmentForURL();
1771                 } else {
1772                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1773                 }
1774                 wfProfileOut( __METHOD__ );
1775                 return $ret;
1776         }
1777
1778         /**
1779          * Get an HTML-escaped version of the URL form, suitable for
1780          * using in a link, without a server name or fragment
1781          *
1782          * @see self::getLocalURL for the arguments.
1783          * @param string $query
1784          * @param bool|string $query2
1785          * @return string The URL
1786          * @deprecated since 1.19
1787          */
1788         public function escapeLocalURL( $query = '', $query2 = false ) {
1789                 wfDeprecated( __METHOD__, '1.19' );
1790                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1791         }
1792
1793         /**
1794          * Get an HTML-escaped version of the URL form, suitable for
1795          * using in a link, including the server name and fragment
1796          *
1797          * @see self::getLocalURL for the arguments.
1798          * @return string The URL
1799          * @deprecated since 1.19
1800          */
1801         public function escapeFullURL( $query = '', $query2 = false ) {
1802                 wfDeprecated( __METHOD__, '1.19' );
1803                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1804         }
1805
1806         /**
1807          * Get the URL form for an internal link.
1808          * - Used in various Squid-related code, in case we have a different
1809          * internal hostname for the server from the exposed one.
1810          *
1811          * This uses $wgInternalServer to qualify the path, or $wgServer
1812          * if $wgInternalServer is not set. If the server variable used is
1813          * protocol-relative, the URL will be expanded to http://
1814          *
1815          * @see self::getLocalURL for the arguments.
1816          * @return string The URL
1817          */
1818         public function getInternalURL( $query = '', $query2 = false ) {
1819                 global $wgInternalServer, $wgServer;
1820                 $query = self::fixUrlQueryArgs( $query, $query2 );
1821                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1822                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1823                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1824                 return $url;
1825         }
1826
1827         /**
1828          * Get the URL for a canonical link, for use in things like IRC and
1829          * e-mail notifications. Uses $wgCanonicalServer and the
1830          * GetCanonicalURL hook.
1831          *
1832          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1833          *
1834          * @see self::getLocalURL for the arguments.
1835          * @return string The URL
1836          * @since 1.18
1837          */
1838         public function getCanonicalURL( $query = '', $query2 = false ) {
1839                 $query = self::fixUrlQueryArgs( $query, $query2 );
1840                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1841                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1842                 return $url;
1843         }
1844
1845         /**
1846          * Get the edit URL for this Title
1847          *
1848          * @return string The URL, or a null string if this is an interwiki link
1849          */
1850         public function getEditURL() {
1851                 if ( $this->isExternal() ) {
1852                         return '';
1853                 }
1854                 $s = $this->getLocalURL( 'action=edit' );
1855
1856                 return $s;
1857         }
1858
1859         /**
1860          * Is $wgUser watching this page?
1861          *
1862          * @deprecated since 1.20; use User::isWatched() instead.
1863          * @return bool
1864          */
1865         public function userIsWatching() {
1866                 global $wgUser;
1867
1868                 if ( is_null( $this->mWatched ) ) {
1869                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1870                                 $this->mWatched = false;
1871                         } else {
1872                                 $this->mWatched = $wgUser->isWatched( $this );
1873                         }
1874                 }
1875                 return $this->mWatched;
1876         }
1877
1878         /**
1879          * Can $wgUser read this page?
1880          *
1881          * @deprecated since 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1882          * @return bool
1883          */
1884         public function userCanRead() {
1885                 wfDeprecated( __METHOD__, '1.19' );
1886                 return $this->userCan( 'read' );
1887         }
1888
1889         /**
1890          * Can $user perform $action on this page?
1891          * This skips potentially expensive cascading permission checks
1892          * as well as avoids expensive error formatting
1893          *
1894          * Suitable for use for nonessential UI controls in common cases, but
1895          * _not_ for functional access control.
1896          *
1897          * May provide false positives, but should never provide a false negative.
1898          *
1899          * @param string $action Action that permission needs to be checked for
1900          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1901          * @return bool
1902          */
1903         public function quickUserCan( $action, $user = null ) {
1904                 return $this->userCan( $action, $user, false );
1905         }
1906
1907         /**
1908          * Can $user perform $action on this page?
1909          *
1910          * @param string $action Action that permission needs to be checked for
1911          * @param User $user User to check (since 1.19); $wgUser will be used if not
1912          *   provided.
1913          * @param bool $doExpensiveQueries Set this to false to avoid doing
1914          *   unnecessary queries.
1915          * @return bool
1916          */
1917         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1918                 if ( !$user instanceof User ) {
1919                         global $wgUser;
1920                         $user = $wgUser;
1921                 }
1922
1923                 return !count( $this->getUserPermissionsErrorsInternal(
1924                         $action, $user, $doExpensiveQueries, true ) );
1925         }
1926
1927         /**
1928          * Can $user perform $action on this page?
1929          *
1930          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1931          *
1932          * @param string $action action that permission needs to be checked for
1933          * @param User $user User to check
1934          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1935          *   queries by skipping checks for cascading protections and user blocks.
1936          * @param array $ignoreErrors of Strings Set this to a list of message keys
1937          *   whose corresponding errors may be ignored.
1938          * @return array Array of arguments to wfMessage to explain permissions problems.
1939          */
1940         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true,
1941                 $ignoreErrors = array()
1942         ) {
1943                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1944
1945                 // Remove the errors being ignored.
1946                 foreach ( $errors as $index => $error ) {
1947                         $error_key = is_array( $error ) ? $error[0] : $error;
1948
1949                         if ( in_array( $error_key, $ignoreErrors ) ) {
1950                                 unset( $errors[$index] );
1951                         }
1952                 }
1953
1954                 return $errors;
1955         }
1956
1957         /**
1958          * Permissions checks that fail most often, and which are easiest to test.
1959          *
1960          * @param string $action the action to check
1961          * @param User $user User to check
1962          * @param array $errors List of current errors
1963          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
1964          * @param bool $short Short circuit on first error
1965          *
1966          * @return array List of errors
1967          */
1968         private function checkQuickPermissions( $action, $user, $errors,
1969                 $doExpensiveQueries, $short
1970         ) {
1971                 if ( !wfRunHooks( 'TitleQuickPermissions',
1972                         array( $this, $user, $action, &$errors, $doExpensiveQueries, $short ) )
1973                 ) {
1974                         return $errors;
1975                 }
1976
1977                 if ( $action == 'create' ) {
1978                         if (
1979                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1980                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1981                         ) {
1982                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1983                         }
1984                 } elseif ( $action == 'move' ) {
1985                         if ( !$user->isAllowed( 'move-rootuserpages' )
1986                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1987                                 // Show user page-specific message only if the user can move other pages
1988                                 $errors[] = array( 'cant-move-user-page' );
1989                         }
1990
1991                         // Check if user is allowed to move files if it's a file
1992                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1993                                 $errors[] = array( 'movenotallowedfile' );
1994                         }
1995
1996                         // Check if user is allowed to move category pages if it's a category page
1997                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1998                                 $errors[] = array( 'cant-move-category-page' );
1999                         }
2000
2001                         if ( !$user->isAllowed( 'move' ) ) {
2002                                 // User can't move anything
2003                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
2004                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
2005                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
2006                                         // custom message if logged-in users without any special rights can move
2007                                         $errors[] = array( 'movenologintext' );
2008                                 } else {
2009                                         $errors[] = array( 'movenotallowed' );
2010                                 }
2011                         }
2012                 } elseif ( $action == 'move-target' ) {
2013                         if ( !$user->isAllowed( 'move' ) ) {
2014                                 // User can't move anything
2015                                 $errors[] = array( 'movenotallowed' );
2016                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
2017                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
2018                                 // Show user page-specific message only if the user can move other pages
2019                                 $errors[] = array( 'cant-move-to-user-page' );
2020                         } elseif ( !$user->isAllowed( 'move-categorypages' )
2021                                         && $this->mNamespace == NS_CATEGORY ) {
2022                                 // Show category page-specific message only if the user can move other pages
2023                                 $errors[] = array( 'cant-move-to-category-page' );
2024                         }
2025                 } elseif ( !$user->isAllowed( $action ) ) {
2026                         $errors[] = $this->missingPermissionError( $action, $short );
2027                 }
2028
2029                 return $errors;
2030         }
2031
2032         /**
2033          * Add the resulting error code to the errors array
2034          *
2035          * @param array $errors List of current errors
2036          * @param array $result Result of errors
2037          *
2038          * @return array List of errors
2039          */
2040         private function resultToError( $errors, $result ) {
2041                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2042                         // A single array representing an error
2043                         $errors[] = $result;
2044                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2045                         // A nested array representing multiple errors
2046                         $errors = array_merge( $errors, $result );
2047                 } elseif ( $result !== '' && is_string( $result ) ) {
2048                         // A string representing a message-id
2049                         $errors[] = array( $result );
2050                 } elseif ( $result === false ) {
2051                         // a generic "We don't want them to do that"
2052                         $errors[] = array( 'badaccess-group0' );
2053                 }
2054                 return $errors;
2055         }
2056
2057         /**
2058          * Check various permission hooks
2059          *
2060          * @param string $action The action to check
2061          * @param User $user User to check
2062          * @param array $errors List of current errors
2063          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2064          * @param bool $short Short circuit on first error
2065          *
2066          * @return array List of errors
2067          */
2068         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
2069                 // Use getUserPermissionsErrors instead
2070                 $result = '';
2071                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2072                         return $result ? array() : array( array( 'badaccess-group0' ) );
2073                 }
2074                 // Check getUserPermissionsErrors hook
2075                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2076                         $errors = $this->resultToError( $errors, $result );
2077                 }
2078                 // Check getUserPermissionsErrorsExpensive hook
2079                 if (
2080                         $doExpensiveQueries
2081                         && !( $short && count( $errors ) > 0 )
2082                         && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2083                 ) {
2084                         $errors = $this->resultToError( $errors, $result );
2085                 }
2086
2087                 return $errors;
2088         }
2089
2090         /**
2091          * Check permissions on special pages & namespaces
2092          *
2093          * @param string $action The action to check
2094          * @param User $user User to check
2095          * @param array $errors List of current errors
2096          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2097          * @param bool $short Short circuit on first error
2098          *
2099          * @return array List of errors
2100          */
2101         private function checkSpecialsAndNSPermissions( $action, $user, $errors,
2102                 $doExpensiveQueries, $short
2103         ) {
2104                 # Only 'createaccount' can be performed on special pages,
2105                 # which don't actually exist in the DB.
2106                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2107                         $errors[] = array( 'ns-specialprotected' );
2108                 }
2109
2110                 # Check $wgNamespaceProtection for restricted namespaces
2111                 if ( $this->isNamespaceProtected( $user ) ) {
2112                         $ns = $this->mNamespace == NS_MAIN ?
2113                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2114                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2115                                 array( 'protectedinterface' ) : array( 'namespaceprotected', $ns );
2116                 }
2117
2118                 return $errors;
2119         }
2120
2121         /**
2122          * Check CSS/JS sub-page permissions
2123          *
2124          * @param string $action The action to check
2125          * @param User $user User to check
2126          * @param array $errors List of current errors
2127          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2128          * @param bool $short Short circuit on first error
2129          *
2130          * @return array List of errors
2131          */
2132         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2133                 # Protect css/js subpages of user pages
2134                 # XXX: this might be better using restrictions
2135                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2136                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2137                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2138                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2139                                         $errors[] = array( 'mycustomcssprotected' );
2140                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2141                                         $errors[] = array( 'mycustomjsprotected' );
2142                                 }
2143                         } else {
2144                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2145                                         $errors[] = array( 'customcssprotected' );
2146                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2147                                         $errors[] = array( 'customjsprotected' );
2148                                 }
2149                         }
2150                 }
2151
2152                 return $errors;
2153         }
2154
2155         /**
2156          * Check against page_restrictions table requirements on this
2157          * page. The user must possess all required rights for this
2158          * action.
2159          *
2160          * @param string $action The action to check
2161          * @param User $user User to check
2162          * @param array $errors List of current errors
2163          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2164          * @param bool $short Short circuit on first error
2165          *
2166          * @return array List of errors
2167          */
2168         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2169                 foreach ( $this->getRestrictions( $action ) as $right ) {
2170                         // Backwards compatibility, rewrite sysop -> editprotected
2171                         if ( $right == 'sysop' ) {
2172                                 $right = 'editprotected';
2173                         }
2174                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2175                         if ( $right == 'autoconfirmed' ) {
2176                                 $right = 'editsemiprotected';
2177                         }
2178                         if ( $right == '' ) {
2179                                 continue;
2180                         }
2181                         if ( !$user->isAllowed( $right ) ) {
2182                                 $errors[] = array( 'protectedpagetext', $right );
2183                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2184                                 $errors[] = array( 'protectedpagetext', 'protect' );
2185                         }
2186                 }
2187
2188                 return $errors;
2189         }
2190
2191         /**
2192          * Check restrictions on cascading pages.
2193          *
2194          * @param string $action The action to check
2195          * @param User $user User to check
2196          * @param array $errors List of current errors
2197          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2198          * @param bool $short Short circuit on first error
2199          *
2200          * @return array List of errors
2201          */
2202         private function checkCascadingSourcesRestrictions( $action, $user, $errors,
2203                 $doExpensiveQueries, $short
2204         ) {
2205                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
2206                         # We /could/ use the protection level on the source page, but it's
2207                         # fairly ugly as we have to establish a precedence hierarchy for pages
2208                         # included by multiple cascade-protected pages. So just restrict
2209                         # it to people with 'protect' permission, as they could remove the
2210                         # protection anyway.
2211                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2212                         # Cascading protection depends on more than this page...
2213                         # Several cascading protected pages may include this page...
2214                         # Check each cascading level
2215                         # This is only for protection restrictions, not for all actions
2216                         if ( isset( $restrictions[$action] ) ) {
2217                                 foreach ( $restrictions[$action] as $right ) {
2218                                         // Backwards compatibility, rewrite sysop -> editprotected
2219                                         if ( $right == 'sysop' ) {
2220                                                 $right = 'editprotected';
2221                                         }
2222                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2223                                         if ( $right == 'autoconfirmed' ) {
2224                                                 $right = 'editsemiprotected';
2225                                         }
2226                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2227                                                 $pages = '';
2228                                                 foreach ( $cascadingSources as $page ) {
2229                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2230                                                 }
2231                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
2232                                         }
2233                                 }
2234                         }
2235                 }
2236
2237                 return $errors;
2238         }
2239
2240         /**
2241          * Check action permissions not already checked in checkQuickPermissions
2242          *
2243          * @param string $action The action to check
2244          * @param User $user User to check
2245          * @param array $errors List of current errors
2246          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2247          * @param bool $short Short circuit on first error
2248          *
2249          * @return array List of errors
2250          */
2251         private function checkActionPermissions( $action, $user, $errors,
2252                 $doExpensiveQueries, $short
2253         ) {
2254                 global $wgDeleteRevisionsLimit, $wgLang;
2255
2256                 if ( $action == 'protect' ) {
2257                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit',
2258                                 $user, $doExpensiveQueries, true ) )
2259                         ) {
2260                                 // If they can't edit, they shouldn't protect.
2261                                 $errors[] = array( 'protect-cantedit' );
2262                         }
2263                 } elseif ( $action == 'create' ) {
2264                         $title_protection = $this->getTitleProtection();
2265                         if ( $title_protection ) {
2266                                 if ( $title_protection['pt_create_perm'] == 'sysop' ) {
2267                                         $title_protection['pt_create_perm'] = 'editprotected'; // B/C
2268                                 }
2269                                 if ( $title_protection['pt_create_perm'] == 'autoconfirmed' ) {
2270                                         $title_protection['pt_create_perm'] = 'editsemiprotected'; // B/C
2271                                 }
2272                                 if ( $title_protection['pt_create_perm'] == ''
2273                                         || !$user->isAllowed( $title_protection['pt_create_perm'] )
2274                                 ) {
2275                                         $errors[] = array(
2276                                                 'titleprotected',
2277                                                 User::whoIs( $title_protection['pt_user'] ),
2278                                                 $title_protection['pt_reason']
2279                                         );
2280                                 }
2281                         }
2282                 } elseif ( $action == 'move' ) {
2283                         // Check for immobile pages
2284                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2285                                 // Specific message for this case
2286                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2287                         } elseif ( !$this->isMovable() ) {
2288                                 // Less specific message for rarer cases
2289                                 $errors[] = array( 'immobile-source-page' );
2290                         }
2291                 } elseif ( $action == 'move-target' ) {
2292                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2293                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2294                         } elseif ( !$this->isMovable() ) {
2295                                 $errors[] = array( 'immobile-target-page' );
2296                         }
2297                 } elseif ( $action == 'delete' ) {
2298                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2299                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2300                         ) {
2301                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2302                         }
2303                 }
2304                 return $errors;
2305         }
2306
2307         /**
2308          * Check that the user isn't blocked from editing.
2309          *
2310          * @param string $action The action to check
2311          * @param User $user User to check
2312          * @param array $errors List of current errors
2313          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2314          * @param bool $short Short circuit on first error
2315          *
2316          * @return array List of errors
2317          */
2318         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2319                 // Account creation blocks handled at userlogin.
2320                 // Unblocking handled in SpecialUnblock
2321                 if ( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2322                         return $errors;
2323                 }
2324
2325                 global $wgEmailConfirmToEdit;
2326
2327                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2328                         $errors[] = array( 'confirmedittext' );
2329                 }
2330
2331                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2332                         // Don't block the user from editing their own talk page unless they've been
2333                         // explicitly blocked from that too.
2334                 } elseif ( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2335                         // @todo FIXME: Pass the relevant context into this function.
2336                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2337                 }
2338
2339                 return $errors;
2340         }
2341
2342         /**
2343          * Check that the user is allowed to read this page.
2344          *
2345          * @param string $action The action to check
2346          * @param User $user User to check
2347          * @param array $errors List of current errors
2348          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2349          * @param bool $short Short circuit on first error
2350          *
2351          * @return array List of errors
2352          */
2353         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2354                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2355
2356                 $whitelisted = false;
2357                 if ( User::isEveryoneAllowed( 'read' ) ) {
2358                         # Shortcut for public wikis, allows skipping quite a bit of code
2359                         $whitelisted = true;
2360                 } elseif ( $user->isAllowed( 'read' ) ) {
2361                         # If the user is allowed to read pages, he is allowed to read all pages
2362                         $whitelisted = true;
2363                 } elseif ( $this->isSpecial( 'Userlogin' )
2364                         || $this->isSpecial( 'ChangePassword' )
2365                         || $this->isSpecial( 'PasswordReset' )
2366                 ) {
2367                         # Always grant access to the login page.
2368                         # Even anons need to be able to log in.
2369                         $whitelisted = true;
2370                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2371                         # Time to check the whitelist
2372                         # Only do these checks is there's something to check against
2373                         $name = $this->getPrefixedText();
2374                         $dbName = $this->getPrefixedDBkey();
2375
2376                         // Check for explicit whitelisting with and without underscores
2377                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2378                                 $whitelisted = true;
2379                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2380                                 # Old settings might have the title prefixed with
2381                                 # a colon for main-namespace pages
2382                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2383                                         $whitelisted = true;
2384                                 }
2385                         } elseif ( $this->isSpecialPage() ) {
2386                                 # If it's a special page, ditch the subpage bit and check again
2387                                 $name = $this->getDBkey();
2388                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2389                                 if ( $name ) {
2390                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2391                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2392                                                 $whitelisted = true;
2393                                         }
2394                                 }
2395                         }
2396                 }
2397
2398                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2399                         $name = $this->getPrefixedText();
2400                         // Check for regex whitelisting
2401                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2402                                 if ( preg_match( $listItem, $name ) ) {
2403                                         $whitelisted = true;
2404                                         break;
2405                                 }
2406                         }
2407                 }
2408
2409                 if ( !$whitelisted ) {
2410                         # If the title is not whitelisted, give extensions a chance to do so...
2411                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2412                         if ( !$whitelisted ) {
2413                                 $errors[] = $this->missingPermissionError( $action, $short );
2414                         }
2415                 }
2416
2417                 return $errors;
2418         }
2419
2420         /**
2421          * Get a description array when the user doesn't have the right to perform
2422          * $action (i.e. when User::isAllowed() returns false)
2423          *
2424          * @param string $action The action to check
2425          * @param bool $short Short circuit on first error
2426          * @return array List of errors
2427          */
2428         private function missingPermissionError( $action, $short ) {
2429                 // We avoid expensive display logic for quickUserCan's and such
2430                 if ( $short ) {
2431                         return array( 'badaccess-group0' );
2432                 }
2433
2434                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2435                         User::getGroupsWithPermission( $action ) );
2436
2437                 if ( count( $groups ) ) {
2438                         global $wgLang;
2439                         return array(
2440                                 'badaccess-groups',
2441                                 $wgLang->commaList( $groups ),
2442                                 count( $groups )
2443                         );
2444                 } else {
2445                         return array( 'badaccess-group0' );
2446                 }
2447         }
2448
2449         /**
2450          * Can $user perform $action on this page? This is an internal function,
2451          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2452          * checks on wfReadOnly() and blocks)
2453          *
2454          * @param string $action Action that permission needs to be checked for
2455          * @param User $user User to check
2456          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
2457          * @param bool $short Set this to true to stop after the first permission error.
2458          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2459          */
2460         protected function getUserPermissionsErrorsInternal( $action, $user,
2461                 $doExpensiveQueries = true, $short = false
2462         ) {
2463                 wfProfileIn( __METHOD__ );
2464
2465                 # Read has special handling
2466                 if ( $action == 'read' ) {
2467                         $checks = array(
2468                                 'checkPermissionHooks',
2469                                 'checkReadPermissions',
2470                         );
2471                 } else {
2472                         $checks = array(
2473                                 'checkQuickPermissions',
2474                                 'checkPermissionHooks',
2475                                 'checkSpecialsAndNSPermissions',
2476                                 'checkCSSandJSPermissions',
2477                                 'checkPageRestrictions',
2478                                 'checkCascadingSourcesRestrictions',
2479                                 'checkActionPermissions',
2480                                 'checkUserBlock'
2481                         );
2482                 }
2483
2484                 $errors = array();
2485                 while ( count( $checks ) > 0 &&
2486                                 !( $short && count( $errors ) > 0 ) ) {
2487                         $method = array_shift( $checks );
2488                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2489                 }
2490
2491                 wfProfileOut( __METHOD__ );
2492                 return $errors;
2493         }
2494
2495         /**
2496          * Get a filtered list of all restriction types supported by this wiki.
2497          * @param bool $exists True to get all restriction types that apply to
2498          * titles that do exist, False for all restriction types that apply to
2499          * titles that do not exist
2500          * @return array
2501          */
2502         public static function getFilteredRestrictionTypes( $exists = true ) {
2503                 global $wgRestrictionTypes;
2504                 $types = $wgRestrictionTypes;
2505                 if ( $exists ) {
2506                         # Remove the create restriction for existing titles
2507                         $types = array_diff( $types, array( 'create' ) );
2508                 } else {
2509                         # Only the create and upload restrictions apply to non-existing titles
2510                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2511                 }
2512                 return $types;
2513         }
2514
2515         /**
2516          * Returns restriction types for the current Title
2517          *
2518          * @return array Applicable restriction types
2519          */
2520         public function getRestrictionTypes() {
2521                 if ( $this->isSpecialPage() ) {
2522                         return array();
2523                 }
2524
2525                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2526
2527                 if ( $this->getNamespace() != NS_FILE ) {
2528                         # Remove the upload restriction for non-file titles
2529                         $types = array_diff( $types, array( 'upload' ) );
2530                 }
2531
2532                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2533
2534                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2535                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2536
2537                 return $types;
2538         }
2539
2540         /**
2541          * Is this title subject to title protection?
2542          * Title protection is the one applied against creation of such title.
2543          *
2544          * @return array|bool An associative array representing any existent title
2545          *   protection, or false if there's none.
2546          */
2547         private function getTitleProtection() {
2548                 // Can't protect pages in special namespaces
2549                 if ( $this->getNamespace() < 0 ) {
2550                         return false;
2551                 }
2552
2553                 // Can't protect pages that exist.
2554                 if ( $this->exists() ) {
2555                         return false;
2556                 }
2557
2558                 if ( $this->mTitleProtection === null ) {
2559                         $dbr = wfGetDB( DB_SLAVE );
2560                         $res = $dbr->select(
2561                                 'protected_titles',
2562                                 array( 'pt_user', 'pt_reason', 'pt_expiry', 'pt_create_perm' ),
2563                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2564                                 __METHOD__
2565                         );
2566
2567                         // fetchRow returns false if there are no rows.
2568                         $this->mTitleProtection = $dbr->fetchRow( $res );
2569                 }
2570                 return $this->mTitleProtection;
2571         }
2572
2573         /**
2574          * Remove any title protection due to page existing
2575          */
2576         public function deleteTitleProtection() {
2577                 $dbw = wfGetDB( DB_MASTER );
2578
2579                 $dbw->delete(
2580                         'protected_titles',
2581                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2582                         __METHOD__
2583                 );
2584                 $this->mTitleProtection = false;
2585         }
2586
2587         /**
2588          * Is this page "semi-protected" - the *only* protection levels are listed
2589          * in $wgSemiprotectedRestrictionLevels?
2590          *
2591          * @param string $action Action to check (default: edit)
2592          * @return bool
2593          */
2594         public function isSemiProtected( $action = 'edit' ) {
2595                 global $wgSemiprotectedRestrictionLevels;
2596
2597                 $restrictions = $this->getRestrictions( $action );
2598                 $semi = $wgSemiprotectedRestrictionLevels;
2599                 if ( !$restrictions || !$semi ) {
2600                         // Not protected, or all protection is full protection
2601                         return false;
2602                 }
2603
2604                 // Remap autoconfirmed to editsemiprotected for BC
2605                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2606                         $semi[$key] = 'editsemiprotected';
2607                 }
2608                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2609                         $restrictions[$key] = 'editsemiprotected';
2610                 }
2611
2612                 return !array_diff( $restrictions, $semi );
2613         }
2614
2615         /**
2616          * Does the title correspond to a protected article?
2617          *
2618          * @param string $action the action the page is protected from,
2619          * by default checks all actions.
2620          * @return bool
2621          */
2622         public function isProtected( $action = '' ) {
2623                 global $wgRestrictionLevels;
2624
2625                 $restrictionTypes = $this->getRestrictionTypes();
2626
2627                 # Special pages have inherent protection
2628                 if ( $this->isSpecialPage() ) {
2629                         return true;
2630                 }
2631
2632                 # Check regular protection levels
2633                 foreach ( $restrictionTypes as $type ) {
2634                         if ( $action == $type || $action == '' ) {
2635                                 $r = $this->getRestrictions( $type );
2636                                 foreach ( $wgRestrictionLevels as $level ) {
2637                                         if ( in_array( $level, $r ) && $level != '' ) {
2638                                                 return true;
2639                                         }
2640                                 }
2641                         }
2642                 }
2643
2644                 return false;
2645         }
2646
2647         /**
2648          * Determines if $user is unable to edit this page because it has been protected
2649          * by $wgNamespaceProtection.
2650          *
2651          * @param User $user User object to check permissions
2652          * @return bool
2653          */
2654         public function isNamespaceProtected( User $user ) {
2655                 global $wgNamespaceProtection;
2656
2657                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2658                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2659                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2660                                         return true;
2661                                 }
2662                         }
2663                 }
2664                 return false;
2665         }
2666
2667         /**
2668          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2669          *
2670          * @return bool If the page is subject to cascading restrictions.
2671          */
2672         public function isCascadeProtected() {
2673                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2674                 return ( $sources > 0 );
2675         }
2676
2677         /**
2678          * Determines whether cascading protection sources have already been loaded from
2679          * the database.
2680          *
2681          * @param bool $getPages True to check if the pages are loaded, or false to check
2682          * if the status is loaded.
2683          * @return bool Whether or not the specified information has been loaded
2684          * @since 1.23
2685          */
2686         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2687                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2688         }
2689
2690         /**
2691          * Cascading protection: Get the source of any cascading restrictions on this page.
2692          *
2693          * @param bool $getPages Whether or not to retrieve the actual pages
2694          *        that the restrictions have come from and the actual restrictions
2695          *        themselves.
2696          * @return array Two elements: First is an array of Title objects of the
2697          *        pages from which cascading restrictions have come, false for
2698          *        none, or true if such restrictions exist but $getPages was not
2699          *        set. Second is an array like that returned by
2700          *        Title::getAllRestrictions(), or an empty array if $getPages is
2701          *        false.
2702          */
2703         public function getCascadeProtectionSources( $getPages = true ) {
2704                 global $wgContLang;
2705                 $pagerestrictions = array();
2706
2707                 if ( $this->mCascadeSources !== null && $getPages ) {
2708                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2709                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2710                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2711                 }
2712
2713                 wfProfileIn( __METHOD__ );
2714
2715                 $dbr = wfGetDB( DB_SLAVE );
2716
2717                 if ( $this->getNamespace() == NS_FILE ) {
2718                         $tables = array( 'imagelinks', 'page_restrictions' );
2719                         $where_clauses = array(
2720                                 'il_to' => $this->getDBkey(),
2721                                 'il_from=pr_page',
2722                                 'pr_cascade' => 1
2723                         );
2724                 } else {
2725                         $tables = array( 'templatelinks', 'page_restrictions' );
2726                         $where_clauses = array(
2727                                 'tl_namespace' => $this->getNamespace(),
2728                                 'tl_title' => $this->getDBkey(),
2729                                 'tl_from=pr_page',
2730                                 'pr_cascade' => 1
2731                         );
2732                 }
2733
2734                 if ( $getPages ) {
2735                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2736                                 'pr_expiry', 'pr_type', 'pr_level' );
2737                         $where_clauses[] = 'page_id=pr_page';
2738                         $tables[] = 'page';
2739                 } else {
2740                         $cols = array( 'pr_expiry' );
2741                 }
2742
2743                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2744
2745                 $sources = $getPages ? array() : false;
2746                 $now = wfTimestampNow();
2747                 $purgeExpired = false;
2748
2749                 foreach ( $res as $row ) {
2750                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2751                         if ( $expiry > $now ) {
2752                                 if ( $getPages ) {
2753                                         $page_id = $row->pr_page;
2754                                         $page_ns = $row->page_namespace;
2755                                         $page_title = $row->page_title;
2756                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2757                                         # Add groups needed for each restriction type if its not already there
2758                                         # Make sure this restriction type still exists
2759
2760                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2761                                                 $pagerestrictions[$row->pr_type] = array();
2762                                         }
2763
2764                                         if (
2765                                                 isset( $pagerestrictions[$row->pr_type] )
2766                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2767                                         ) {
2768                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2769                                         }
2770                                 } else {
2771                                         $sources = true;
2772                                 }
2773                         } else {
2774                                 // Trigger lazy purge of expired restrictions from the db
2775                                 $purgeExpired = true;
2776                         }
2777                 }
2778                 if ( $purgeExpired ) {
2779                         Title::purgeExpiredRestrictions();
2780                 }
2781
2782                 if ( $getPages ) {
2783                         $this->mCascadeSources = $sources;
2784                         $this->mCascadingRestrictions = $pagerestrictions;
2785                 } else {
2786                         $this->mHasCascadingRestrictions = $sources;
2787                 }
2788
2789                 wfProfileOut( __METHOD__ );
2790                 return array( $sources, $pagerestrictions );
2791         }
2792
2793         /**
2794          * Accessor for mRestrictionsLoaded
2795          *
2796          * @return bool Whether or not the page's restrictions have already been
2797          * loaded from the database
2798          * @since 1.23
2799          */
2800         public function areRestrictionsLoaded() {
2801                 return $this->mRestrictionsLoaded;
2802         }
2803
2804         /**
2805          * Accessor/initialisation for mRestrictions
2806          *
2807          * @param string $action Action that permission needs to be checked for
2808          * @return array Restriction levels needed to take the action. All levels
2809          *     are required.
2810          */
2811         public function getRestrictions( $action ) {
2812                 if ( !$this->mRestrictionsLoaded ) {
2813                         $this->loadRestrictions();
2814                 }
2815                 return isset( $this->mRestrictions[$action] )
2816                                 ? $this->mRestrictions[$action]
2817                                 : array();
2818         }
2819
2820         /**
2821          * Accessor/initialisation for mRestrictions
2822          *
2823          * @return array Keys are actions, values are arrays as returned by
2824          *     Title::getRestrictions()
2825          * @since 1.23
2826          */
2827         public function getAllRestrictions() {
2828                 if ( !$this->mRestrictionsLoaded ) {
2829                         $this->loadRestrictions();
2830                 }
2831                 return $this->mRestrictions;
2832         }
2833
2834         /**
2835          * Get the expiry time for the restriction against a given action
2836          *
2837          * @param string $action
2838          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2839          *     or not protected at all, or false if the action is not recognised.
2840          */
2841         public function getRestrictionExpiry( $action ) {
2842                 if ( !$this->mRestrictionsLoaded ) {
2843                         $this->loadRestrictions();
2844                 }
2845                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2846         }
2847
2848         /**
2849          * Returns cascading restrictions for the current article
2850          *
2851          * @return bool
2852          */
2853         function areRestrictionsCascading() {
2854                 if ( !$this->mRestrictionsLoaded ) {
2855                         $this->loadRestrictions();
2856                 }
2857
2858                 return $this->mCascadeRestriction;
2859         }
2860
2861         /**
2862          * Loads a string into mRestrictions array
2863          *
2864          * @param ResultWrapper $res Resource restrictions as an SQL result.
2865          * @param string $oldFashionedRestrictions Comma-separated list of page
2866          *        restrictions from page table (pre 1.10)
2867          */
2868         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2869                 $rows = array();
2870
2871                 foreach ( $res as $row ) {
2872                         $rows[] = $row;
2873                 }
2874
2875                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2876         }
2877
2878         /**
2879          * Compiles list of active page restrictions from both page table (pre 1.10)
2880          * and page_restrictions table for this existing page.
2881          * Public for usage by LiquidThreads.
2882          *
2883          * @param array $rows Array of db result objects
2884          * @param string $oldFashionedRestrictions Comma-separated list of page
2885          *   restrictions from page table (pre 1.10)
2886          */
2887         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2888                 global $wgContLang;
2889                 $dbr = wfGetDB( DB_SLAVE );
2890
2891                 $restrictionTypes = $this->getRestrictionTypes();
2892
2893                 foreach ( $restrictionTypes as $type ) {
2894                         $this->mRestrictions[$type] = array();
2895                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2896                 }
2897
2898                 $this->mCascadeRestriction = false;
2899
2900                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2901
2902                 if ( $oldFashionedRestrictions === null ) {
2903                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2904                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2905                 }
2906
2907                 if ( $oldFashionedRestrictions != '' ) {
2908
2909                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2910                                 $temp = explode( '=', trim( $restrict ) );
2911                                 if ( count( $temp ) == 1 ) {
2912                                         // old old format should be treated as edit/move restriction
2913                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2914                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2915                                 } else {
2916                                         $restriction = trim( $temp[1] );
2917                                         if ( $restriction != '' ) { //some old entries are empty
2918                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2919                                         }
2920                                 }
2921                         }
2922
2923                         $this->mOldRestrictions = true;
2924
2925                 }
2926
2927                 if ( count( $rows ) ) {
2928                         # Current system - load second to make them override.
2929                         $now = wfTimestampNow();
2930                         $purgeExpired = false;
2931
2932                         # Cycle through all the restrictions.
2933                         foreach ( $rows as $row ) {
2934
2935                                 // Don't take care of restrictions types that aren't allowed
2936                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2937                                         continue;
2938                                 }
2939
2940                                 // This code should be refactored, now that it's being used more generally,
2941                                 // But I don't really see any harm in leaving it in Block for now -werdna
2942                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2943
2944                                 // Only apply the restrictions if they haven't expired!
2945                                 if ( !$expiry || $expiry > $now ) {
2946                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2947                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2948
2949                                         $this->mCascadeRestriction |= $row->pr_cascade;
2950                                 } else {
2951                                         // Trigger a lazy purge of expired restrictions
2952                                         $purgeExpired = true;
2953                                 }
2954                         }
2955
2956                         if ( $purgeExpired ) {
2957                                 Title::purgeExpiredRestrictions();
2958                         }
2959                 }
2960
2961                 $this->mRestrictionsLoaded = true;
2962         }
2963
2964         /**
2965          * Load restrictions from the page_restrictions table
2966          *
2967          * @param string $oldFashionedRestrictions Comma-separated list of page
2968          *   restrictions from page table (pre 1.10)
2969          */
2970         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2971                 global $wgContLang;
2972                 if ( !$this->mRestrictionsLoaded ) {
2973                         if ( $this->exists() ) {
2974                                 $dbr = wfGetDB( DB_SLAVE );
2975
2976                                 $res = $dbr->select(
2977                                         'page_restrictions',
2978                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2979                                         array( 'pr_page' => $this->getArticleID() ),
2980                                         __METHOD__
2981                                 );
2982
2983                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2984                         } else {
2985                                 $title_protection = $this->getTitleProtection();
2986
2987                                 if ( $title_protection ) {
2988                                         $now = wfTimestampNow();
2989                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2990
2991                                         if ( !$expiry || $expiry > $now ) {
2992                                                 // Apply the restrictions
2993                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2994                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2995                                         } else { // Get rid of the old restrictions
2996                                                 Title::purgeExpiredRestrictions();
2997                                                 $this->mTitleProtection = false;
2998                                         }
2999                                 } else {
3000                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
3001                                 }
3002                                 $this->mRestrictionsLoaded = true;
3003                         }
3004                 }
3005         }
3006
3007         /**
3008          * Flush the protection cache in this object and force reload from the database.
3009          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3010          */
3011         public function flushRestrictions() {
3012                 $this->mRestrictionsLoaded = false;
3013                 $this->mTitleProtection = null;
3014         }
3015
3016         /**
3017          * Purge expired restrictions from the page_restrictions table
3018          */
3019         static function purgeExpiredRestrictions() {
3020                 if ( wfReadOnly() ) {
3021                         return;
3022                 }
3023
3024                 $method = __METHOD__;
3025                 $dbw = wfGetDB( DB_MASTER );
3026                 $dbw->onTransactionIdle( function() use ( $dbw, $method ) {
3027                         $dbw->delete(
3028                                 'page_restrictions',
3029                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3030                                 $method
3031                         );
3032                         $dbw->delete(
3033                                 'protected_titles',
3034                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3035                                 $method
3036                         );
3037                 } );
3038         }
3039
3040         /**
3041          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3042          *
3043          * @return bool
3044          */
3045         public function hasSubpages() {
3046                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3047                         # Duh
3048                         return false;
3049                 }
3050
3051                 # We dynamically add a member variable for the purpose of this method
3052                 # alone to cache the result.  There's no point in having it hanging
3053                 # around uninitialized in every Title object; therefore we only add it
3054                 # if needed and don't declare it statically.
3055                 if ( $this->mHasSubpages === null ) {
3056                         $this->mHasSubpages = false;
3057                         $subpages = $this->getSubpages( 1 );
3058                         if ( $subpages instanceof TitleArray ) {
3059                                 $this->mHasSubpages = (bool)$subpages->count();
3060                         }
3061                 }
3062
3063                 return $this->mHasSubpages;
3064         }
3065
3066         /**
3067          * Get all subpages of this page.
3068          *
3069          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3070          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3071          *  doesn't allow subpages
3072          */
3073         public function getSubpages( $limit = -1 ) {
3074                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3075                         return array();
3076                 }
3077
3078                 $dbr = wfGetDB( DB_SLAVE );
3079                 $conds['page_namespace'] = $this->getNamespace();
3080                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3081                 $options = array();
3082                 if ( $limit > -1 ) {
3083                         $options['LIMIT'] = $limit;
3084                 }
3085                 $this->mSubpages = TitleArray::newFromResult(
3086                         $dbr->select( 'page',
3087                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3088                                 $conds,
3089                                 __METHOD__,
3090                                 $options
3091                         )
3092                 );
3093                 return $this->mSubpages;
3094         }
3095
3096         /**
3097          * Is there a version of this page in the deletion archive?
3098          *
3099          * @return int The number of archived revisions
3100          */
3101         public function isDeleted() {
3102                 if ( $this->getNamespace() < 0 ) {
3103                         $n = 0;
3104                 } else {
3105                         $dbr = wfGetDB( DB_SLAVE );
3106
3107                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3108                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3109                                 __METHOD__
3110                         );
3111                         if ( $this->getNamespace() == NS_FILE ) {
3112                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3113                                         array( 'fa_name' => $this->getDBkey() ),
3114                                         __METHOD__
3115                                 );
3116                         }
3117                 }
3118                 return (int)$n;
3119         }
3120
3121         /**
3122          * Is there a version of this page in the deletion archive?
3123          *
3124          * @return bool
3125          */
3126         public function isDeletedQuick() {
3127                 if ( $this->getNamespace() < 0 ) {
3128                         return false;
3129                 }
3130                 $dbr = wfGetDB( DB_SLAVE );
3131                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3132                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3133                         __METHOD__
3134                 );
3135                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3136                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3137                                 array( 'fa_name' => $this->getDBkey() ),
3138                                 __METHOD__
3139                         );
3140                 }
3141                 return $deleted;
3142         }
3143
3144         /**
3145          * Get the article ID for this Title from the link cache,
3146          * adding it if necessary
3147          *
3148          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3149          *  for update
3150          * @return int The ID
3151          */
3152         public function getArticleID( $flags = 0 ) {
3153                 if ( $this->getNamespace() < 0 ) {
3154                         $this->mArticleID = 0;
3155                         return $this->mArticleID;
3156                 }
3157                 $linkCache = LinkCache::singleton();
3158                 if ( $flags & self::GAID_FOR_UPDATE ) {
3159                         $oldUpdate = $linkCache->forUpdate( true );
3160                         $linkCache->clearLink( $this );
3161                         $this->mArticleID = $linkCache->addLinkObj( $this );
3162                         $linkCache->forUpdate( $oldUpdate );
3163                 } else {
3164                         if ( -1 == $this->mArticleID ) {
3165                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3166                         }
3167                 }
3168                 return $this->mArticleID;
3169         }
3170
3171         /**
3172          * Is this an article that is a redirect page?
3173          * Uses link cache, adding it if necessary
3174          *
3175          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3176          * @return bool
3177          */
3178         public function isRedirect( $flags = 0 ) {
3179                 if ( !is_null( $this->mRedirect ) ) {
3180                         return $this->mRedirect;
3181                 }
3182                 # Calling getArticleID() loads the field from cache as needed
3183                 if ( !$this->getArticleID( $flags ) ) {
3184                         $this->mRedirect = false;
3185                         return $this->mRedirect;
3186                 }
3187
3188                 $linkCache = LinkCache::singleton();
3189                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3190                 if ( $cached === null ) {
3191                         # Trust LinkCache's state over our own
3192                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3193                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3194                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3195                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3196                         # LinkCache to refresh its data from the master.
3197                         $this->mRedirect = false;
3198                         return $this->mRedirect;
3199                 }
3200
3201                 $this->mRedirect = (bool)$cached;
3202
3203                 return $this->mRedirect;
3204         }
3205
3206         /**
3207          * What is the length of this page?
3208          * Uses link cache, adding it if necessary
3209          *
3210          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3211          * @return int
3212          */
3213         public function getLength( $flags = 0 ) {
3214                 if ( $this->mLength != -1 ) {
3215                         return $this->mLength;
3216                 }
3217                 # Calling getArticleID() loads the field from cache as needed
3218                 if ( !$this->getArticleID( $flags ) ) {
3219                         $this->mLength = 0;
3220                         return $this->mLength;
3221                 }
3222                 $linkCache = LinkCache::singleton();
3223                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3224                 if ( $cached === null ) {
3225                         # Trust LinkCache's state over our own, as for isRedirect()
3226                         $this->mLength = 0;
3227                         return $this->mLength;
3228                 }
3229
3230                 $this->mLength = intval( $cached );
3231
3232                 return $this->mLength;
3233         }
3234
3235         /**
3236          * What is the page_latest field for this page?
3237          *
3238          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3239          * @return int Int or 0 if the page doesn't exist
3240          */
3241         public function getLatestRevID( $flags = 0 ) {
3242                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3243                         return intval( $this->mLatestID );
3244                 }
3245                 # Calling getArticleID() loads the field from cache as needed
3246                 if ( !$this->getArticleID( $flags ) ) {
3247                         $this->mLatestID = 0;
3248                         return $this->mLatestID;
3249                 }
3250                 $linkCache = LinkCache::singleton();
3251                 $linkCache->addLinkObj( $this );
3252                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3253                 if ( $cached === null ) {
3254                         # Trust LinkCache's state over our own, as for isRedirect()
3255                         $this->mLatestID = 0;
3256                         return $this->mLatestID;
3257                 }
3258
3259                 $this->mLatestID = intval( $cached );
3260
3261                 return $this->mLatestID;
3262         }
3263
3264         /**
3265          * This clears some fields in this object, and clears any associated
3266          * keys in the "bad links" section of the link cache.
3267          *
3268          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3269          * loading of the new page_id. It's also called from
3270          * WikiPage::doDeleteArticleReal()
3271          *
3272          * @param int $newid The new Article ID
3273          */
3274         public function resetArticleID( $newid ) {
3275                 $linkCache = LinkCache::singleton();
3276                 $linkCache->clearLink( $this );
3277
3278                 if ( $newid === false ) {
3279                         $this->mArticleID = -1;
3280                 } else {
3281                         $this->mArticleID = intval( $newid );
3282                 }
3283                 $this->mRestrictionsLoaded = false;
3284                 $this->mRestrictions = array();
3285                 $this->mRedirect = null;
3286                 $this->mLength = -1;
3287                 $this->mLatestID = false;
3288                 $this->mContentModel = false;
3289                 $this->mEstimateRevisions = null;
3290                 $this->mPageLanguage = false;
3291                 $this->mDbPageLanguage = null;
3292         }
3293
3294         /**
3295          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3296          *
3297          * @param string $text Containing title to capitalize
3298          * @param int $ns Namespace index, defaults to NS_MAIN
3299          * @return string Containing capitalized title
3300          */
3301         public static function capitalize( $text, $ns = NS_MAIN ) {
3302                 global $wgContLang;
3303
3304                 if ( MWNamespace::isCapitalized( $ns ) ) {
3305                         return $wgContLang->ucfirst( $text );
3306                 } else {
3307                         return $text;
3308                 }
3309         }
3310
3311         /**
3312          * Secure and split - main initialisation function for this object
3313          *
3314          * Assumes that mDbkeyform has been set, and is urldecoded
3315          * and uses underscores, but not otherwise munged.  This function
3316          * removes illegal characters, splits off the interwiki and
3317          * namespace prefixes, sets the other forms, and canonicalizes
3318          * everything.
3319          *
3320          * @return bool True on success
3321          */
3322         private function secureAndSplit() {
3323                 # Initialisation
3324                 $this->mInterwiki = '';
3325                 $this->mFragment = '';
3326                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3327
3328                 $dbkey = $this->mDbkeyform;
3329
3330                 try {
3331                         // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3332                         //        the parsing code with Title, while avoiding massive refactoring.
3333                         // @todo: get rid of secureAndSplit, refactor parsing code.
3334                         $parser = $this->getTitleParser();
3335                         $parts = $parser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3336                 } catch ( MalformedTitleException $ex ) {
3337                         return false;
3338                 }
3339
3340                 # Fill fields
3341                 $this->setFragment( '#' . $parts['fragment'] );
3342                 $this->mInterwiki = $parts['interwiki'];
3343                 $this->mNamespace = $parts['namespace'];
3344                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3345
3346                 $this->mDbkeyform = $parts['dbkey'];
3347                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3348                 $this->mTextform = str_replace( '_', ' ', $this->mDbkeyform );
3349
3350                 # We already know that some pages won't be in the database!
3351                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3352                         $this->mArticleID = 0;
3353                 }
3354
3355                 return true;
3356         }
3357
3358         /**
3359          * Get an array of Title objects linking to this Title
3360          * Also stores the IDs in the link cache.
3361          *
3362          * WARNING: do not use this function on arbitrary user-supplied titles!
3363          * On heavily-used templates it will max out the memory.
3364          *
3365          * @param array $options May be FOR UPDATE
3366          * @param string $table Table name
3367          * @param string $prefix Fields prefix
3368          * @return Title[] Array of Title objects linking here
3369          */
3370         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3371                 if ( count( $options ) > 0 ) {
3372                         $db = wfGetDB( DB_MASTER );
3373                 } else {
3374                         $db = wfGetDB( DB_SLAVE );
3375                 }
3376
3377                 $res = $db->select(
3378                         array( 'page', $table ),
3379                         self::getSelectFields(),
3380                         array(
3381                                 "{$prefix}_from=page_id",
3382                                 "{$prefix}_namespace" => $this->getNamespace(),
3383                                 "{$prefix}_title" => $this->getDBkey() ),
3384                         __METHOD__,
3385                         $options
3386                 );
3387
3388                 $retVal = array();
3389                 if ( $res->numRows() ) {
3390                         $linkCache = LinkCache::singleton();
3391                         foreach ( $res as $row ) {
3392                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3393                                 if ( $titleObj ) {
3394                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3395                                         $retVal[] = $titleObj;
3396                                 }
3397                         }
3398                 }
3399                 return $retVal;
3400         }
3401
3402         /**
3403          * Get an array of Title objects using this Title as a template
3404          * Also stores the IDs in the link cache.
3405          *
3406          * WARNING: do not use this function on arbitrary user-supplied titles!
3407          * On heavily-used templates it will max out the memory.
3408          *
3409          * @param array $options May be FOR UPDATE
3410          * @return Title[] Array of Title the Title objects linking here
3411          */
3412         public function getTemplateLinksTo( $options = array() ) {
3413                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3414         }
3415
3416         /**
3417          * Get an array of Title objects linked from this Title
3418          * Also stores the IDs in the link cache.
3419          *
3420          * WARNING: do not use this function on arbitrary user-supplied titles!
3421          * On heavily-used templates it will max out the memory.
3422          *
3423          * @param array $options May be FOR UPDATE
3424          * @param string $table Table name
3425          * @param string $prefix Fields prefix
3426          * @return array Array of Title objects linking here
3427          */
3428         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3429                 global $wgContentHandlerUseDB;
3430
3431                 $id = $this->getArticleID();
3432
3433                 # If the page doesn't exist; there can't be any link from this page
3434                 if ( !$id ) {
3435                         return array();
3436                 }
3437
3438                 if ( count( $options ) > 0 ) {
3439                         $db = wfGetDB( DB_MASTER );
3440                 } else {
3441                         $db = wfGetDB( DB_SLAVE );
3442                 }
3443
3444                 $namespaceFiled = "{$prefix}_namespace";
3445                 $titleField = "{$prefix}_title";
3446
3447                 $fields = array(
3448                         $namespaceFiled,
3449                         $titleField,
3450                         'page_id',
3451                         'page_len',
3452                         'page_is_redirect',
3453                         'page_latest'
3454                 );
3455
3456                 if ( $wgContentHandlerUseDB ) {
3457                         $fields[] = 'page_content_model';
3458                 }
3459
3460                 $res = $db->select(
3461                         array( $table, 'page' ),
3462                         $fields,
3463                         array( "{$prefix}_from" => $id ),
3464                         __METHOD__,
3465                         $options,
3466                         array( 'page' => array(
3467                                 'LEFT JOIN',
3468                                 array( "page_namespace=$namespaceFiled", "page_title=$titleField" )
3469                         ) )
3470                 );
3471
3472                 $retVal = array();
3473                 if ( $res->numRows() ) {
3474                         $linkCache = LinkCache::singleton();
3475                         foreach ( $res as $row ) {
3476                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3477                                 if ( $titleObj ) {
3478                                         if ( $row->page_id ) {
3479                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3480                                         } else {
3481                                                 $linkCache->addBadLinkObj( $titleObj );
3482                                         }
3483                                         $retVal[] = $titleObj;
3484                                 }
3485                         }
3486                 }
3487                 return $retVal;
3488         }
3489
3490         /**
3491          * Get an array of Title objects used on this Title as a template
3492          * Also stores the IDs in the link cache.
3493          *
3494          * WARNING: do not use this function on arbitrary user-supplied titles!
3495          * On heavily-used templates it will max out the memory.
3496          *
3497          * @param array $options May be FOR UPDATE
3498          * @return Title[] Array of Title the Title objects used here
3499          */
3500         public function getTemplateLinksFrom( $options = array() ) {
3501                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3502         }
3503
3504         /**
3505          * Get an array of Title objects referring to non-existent articles linked
3506          * from this page.
3507          *
3508          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3509          *   should use redirect table in this case).
3510          * @return Title[] Array of Title the Title objects
3511          */
3512         public function getBrokenLinksFrom() {
3513                 if ( $this->getArticleID() == 0 ) {
3514                         # All links from article ID 0 are false positives
3515                         return array();
3516                 }
3517
3518                 $dbr = wfGetDB( DB_SLAVE );
3519                 $res = $dbr->select(
3520                         array( 'page', 'pagelinks' ),
3521                         array( 'pl_namespace', 'pl_title' ),
3522                         array(
3523                                 'pl_from' => $this->getArticleID(),
3524                                 'page_namespace IS NULL'
3525                         ),
3526                         __METHOD__, array(),
3527                         array(
3528                                 'page' => array(
3529                                         'LEFT JOIN',
3530                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3531                                 )
3532                         )
3533                 );
3534
3535                 $retVal = array();
3536                 foreach ( $res as $row ) {
3537                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3538                 }
3539                 return $retVal;
3540         }
3541
3542         /**
3543          * Get a list of URLs to purge from the Squid cache when this
3544          * page changes
3545          *
3546          * @return string[] Array of String the URLs
3547          */
3548         public function getSquidURLs() {
3549                 $urls = array(
3550                         $this->getInternalURL(),
3551                         $this->getInternalURL( 'action=history' )
3552                 );
3553
3554                 $pageLang = $this->getPageLanguage();
3555                 if ( $pageLang->hasVariants() ) {
3556                         $variants = $pageLang->getVariants();
3557                         foreach ( $variants as $vCode ) {
3558                                 $urls[] = $this->getInternalURL( '', $vCode );
3559                         }
3560                 }
3561
3562                 // If we are looking at a css/js user subpage, purge the action=raw.
3563                 if ( $this->isJsSubpage() ) {
3564                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3565                 } elseif ( $this->isCssSubpage() ) {
3566                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3567                 }
3568
3569                 wfRunHooks( 'TitleSquidURLs', array( $this, &$urls ) );
3570                 return $urls;
3571         }
3572
3573         /**
3574          * Purge all applicable Squid URLs
3575          */
3576         public function purgeSquid() {
3577                 global $wgUseSquid;
3578                 if ( $wgUseSquid ) {
3579                         $urls = $this->getSquidURLs();
3580                         $u = new SquidUpdate( $urls );
3581                         $u->doUpdate();
3582                 }
3583         }
3584
3585         /**
3586          * Move this page without authentication
3587          *
3588          * @param Title $nt The new page Title
3589          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3590          */
3591         public function moveNoAuth( &$nt ) {
3592                 return $this->moveTo( $nt, false );
3593         }
3594
3595         /**
3596          * Check whether a given move operation would be valid.
3597          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3598          *
3599          * @param Title $nt The new title
3600          * @param bool $auth Indicates whether $wgUser's permissions
3601          *  should be checked
3602          * @param string $reason Is the log summary of the move, used for spam checking
3603          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3604          */
3605         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3606                 global $wgUser, $wgContentHandlerUseDB;
3607
3608                 $errors = array();
3609                 if ( !$nt ) {
3610                         // Normally we'd add this to $errors, but we'll get
3611                         // lots of syntax errors if $nt is not an object
3612                         return array( array( 'badtitletext' ) );
3613                 }
3614                 if ( $this->equals( $nt ) ) {
3615                         $errors[] = array( 'selfmove' );
3616                 }
3617                 if ( !$this->isMovable() ) {
3618                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3619                 }
3620                 if ( $nt->isExternal() ) {
3621                         $errors[] = array( 'immobile-target-namespace-iw' );
3622                 }
3623                 if ( !$nt->isMovable() ) {
3624                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3625                 }
3626
3627                 $oldid = $this->getArticleID();
3628                 $newid = $nt->getArticleID();
3629
3630                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3631                         $errors[] = array( 'articleexists' );
3632                 }
3633                 if (
3634                         ( $this->getDBkey() == '' ) ||
3635                         ( !$oldid ) ||
3636                         ( $nt->getDBkey() == '' )
3637                 ) {
3638                         $errors[] = array( 'badarticleerror' );
3639                 }
3640
3641                 // Content model checks
3642                 if ( !$wgContentHandlerUseDB &&
3643                                 $this->getContentModel() !== $nt->getContentModel() ) {
3644                         // can't move a page if that would change the page's content model
3645                         $errors[] = array(
3646                                 'bad-target-model',
3647                                 ContentHandler::getLocalizedName( $this->getContentModel() ),
3648                                 ContentHandler::getLocalizedName( $nt->getContentModel() )
3649                         );
3650                 }
3651
3652                 // Image-specific checks
3653                 if ( $this->getNamespace() == NS_FILE ) {
3654                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3655                 }
3656
3657                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3658                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3659                 }
3660
3661                 if ( $auth ) {
3662                         $errors = wfMergeErrorArrays( $errors,
3663                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3664                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3665                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3666                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3667                 }
3668
3669                 $match = EditPage::matchSummarySpamRegex( $reason );
3670                 if ( $match !== false ) {
3671                         // This is kind of lame, won't display nice
3672                         $errors[] = array( 'spamprotectiontext' );
3673                 }
3674
3675                 $err = null;
3676                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3677                         $errors[] = array( 'hookaborted', $err );
3678                 }
3679
3680                 # The move is allowed only if (1) the target doesn't exist, or
3681                 # (2) the target is a redirect to the source, and has no history
3682                 # (so we can undo bad moves right after they're done).
3683
3684                 if ( 0 != $newid ) { # Target exists; check for validity
3685                         if ( !$this->isValidMoveTarget( $nt ) ) {
3686                                 $errors[] = array( 'articleexists' );
3687                         }
3688                 } else {
3689                         $tp = $nt->getTitleProtection();
3690                         $right = $tp['pt_create_perm'];
3691                         if ( $right == 'sysop' ) {
3692                                 $right = 'editprotected'; // B/C
3693                         }
3694                         if ( $right == 'autoconfirmed' ) {
3695                                 $right = 'editsemiprotected'; // B/C
3696                         }
3697                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3698                                 $errors[] = array( 'cantmove-titleprotected' );
3699                         }
3700                 }
3701                 if ( empty( $errors ) ) {
3702                         return true;
3703                 }
3704                 return $errors;
3705         }
3706
3707         /**
3708          * Check if the requested move target is a valid file move target
3709          * @param Title $nt Target title
3710          * @return array List of errors
3711          */
3712         protected function validateFileMoveOperation( $nt ) {
3713                 global $wgUser;
3714
3715                 $errors = array();
3716
3717                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3718
3719                 $file = wfLocalFile( $this );
3720                 if ( $file->exists() ) {
3721                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3722                                 $errors[] = array( 'imageinvalidfilename' );
3723                         }
3724                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3725                                 $errors[] = array( 'imagetypemismatch' );
3726                         }
3727                 }
3728
3729                 if ( $nt->getNamespace() != NS_FILE ) {
3730                         $errors[] = array( 'imagenocrossnamespace' );
3731                         // From here we want to do checks on a file object, so if we can't
3732                         // create one, we must return.
3733                         return $errors;
3734                 }
3735
3736                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3737
3738                 $destFile = wfLocalFile( $nt );
3739                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3740                         $errors[] = array( 'file-exists-sharedrepo' );
3741                 }
3742
3743                 return $errors;
3744         }
3745
3746         /**
3747          * Move a title to a new location
3748          *
3749          * @param Title $nt The new title
3750          * @param bool $auth Indicates whether $wgUser's permissions
3751          *  should be checked
3752          * @param string $reason The reason for the move
3753          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3754          *  Ignored if the user doesn't have the suppressredirect right.
3755          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3756          */
3757         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3758                 global $wgUser;
3759                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3760                 if ( is_array( $err ) ) {
3761                         // Auto-block user's IP if the account was "hard" blocked
3762                         $wgUser->spreadAnyEditBlock();
3763                         return $err;
3764                 }
3765                 // Check suppressredirect permission
3766                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3767                         $createRedirect = true;
3768                 }
3769
3770                 wfRunHooks( 'TitleMove', array( $this, $nt, $wgUser ) );
3771
3772                 // If it is a file, move it first.
3773                 // It is done before all other moving stuff is done because it's hard to revert.
3774                 $dbw = wfGetDB( DB_MASTER );
3775                 if ( $this->getNamespace() == NS_FILE ) {
3776                         $file = wfLocalFile( $this );
3777                         if ( $file->exists() ) {
3778                                 $status = $file->move( $nt );
3779                                 if ( !$status->isOk() ) {
3780                                         return $status->getErrorsArray();
3781                                 }
3782                         }
3783                         // Clear RepoGroup process cache
3784                         RepoGroup::singleton()->clearCache( $this );
3785                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3786                 }
3787
3788                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3789                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3790                 $protected = $this->isProtected();
3791
3792                 // Do the actual move
3793                 $this->moveToInternal( $nt, $reason, $createRedirect );
3794
3795                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3796                 // cl_timestamp, which may disturb time-based lists on some sites.
3797                 $prefixes = $dbw->select(
3798                         'categorylinks',
3799                         array( 'cl_sortkey_prefix', 'cl_to' ),
3800                         array( 'cl_from' => $pageid ),
3801                         __METHOD__
3802                 );
3803                 foreach ( $prefixes as $prefixRow ) {
3804                         $prefix = $prefixRow->cl_sortkey_prefix;
3805                         $catTo = $prefixRow->cl_to;
3806                         $dbw->update( 'categorylinks',
3807                                 array(
3808                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3809                                                 $nt->getCategorySortkey( $prefix ) ),
3810                                         'cl_timestamp=cl_timestamp' ),
3811                                 array(
3812                                         'cl_from' => $pageid,
3813                                         'cl_to' => $catTo ),
3814                                 __METHOD__
3815                         );
3816                 }
3817
3818                 $redirid = $this->getArticleID();
3819
3820                 if ( $protected ) {
3821                         # Protect the redirect title as the title used to be...
3822                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3823                                 array(
3824                                         'pr_page' => $redirid,
3825                                         'pr_type' => 'pr_type',
3826                                         'pr_level' => 'pr_level',
3827                                         'pr_cascade' => 'pr_cascade',
3828                                         'pr_user' => 'pr_user',
3829                                         'pr_expiry' => 'pr_expiry'
3830                                 ),
3831                                 array( 'pr_page' => $pageid ),
3832                                 __METHOD__,
3833                                 array( 'IGNORE' )
3834                         );
3835                         # Update the protection log
3836                         $log = new LogPage( 'protect' );
3837                         $comment = wfMessage(
3838                                 'prot_1movedto2',
3839                                 $this->getPrefixedText(),
3840                                 $nt->getPrefixedText()
3841                         )->inContentLanguage()->text();
3842                         if ( $reason ) {
3843                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3844                         }
3845                         // @todo FIXME: $params?
3846                         $logId = $log->addEntry(
3847                                 'move_prot',
3848                                 $nt,
3849                                 $comment,
3850                                 array( $this->getPrefixedText() ),
3851                                 $wgUser
3852                         );
3853
3854                         // reread inserted pr_ids for log relation
3855                         $insertedPrIds = $dbw->select(
3856                                 'page_restrictions',
3857                                 'pr_id',
3858                                 array( 'pr_page' => $redirid ),
3859                                 __METHOD__
3860                         );
3861                         $logRelationsValues = array();
3862                         foreach ( $insertedPrIds as $prid ) {
3863                                 $logRelationsValues[] = $prid->pr_id;
3864                         }
3865                         $log->addRelations( 'pr_id', $logRelationsValues, $logId );
3866                 }
3867
3868                 # Update watchlists
3869                 $oldnamespace = MWNamespace::getSubject( $this->getNamespace() );
3870                 $newnamespace = MWNamespace::getSubject( $nt->getNamespace() );
3871                 $oldtitle = $this->getDBkey();
3872                 $newtitle = $nt->getDBkey();
3873
3874                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3875                         WatchedItem::duplicateEntries( $this, $nt );
3876                 }
3877
3878                 $dbw->commit( __METHOD__ );
3879
3880                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid, $reason ) );
3881                 return true;
3882         }
3883
3884         /**
3885          * Move page to a title which is either a redirect to the
3886          * source page or nonexistent
3887          *
3888          * @param Title $nt The page to move to, which should be a redirect or nonexistent
3889          * @param string $reason The reason for the move
3890          * @param bool $createRedirect Whether to leave a redirect at the old title. Does not check
3891          *   if the user has the suppressredirect right
3892          * @throws MWException
3893          */
3894         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3895                 global $wgUser, $wgContLang;
3896
3897                 if ( $nt->exists() ) {
3898                         $moveOverRedirect = true;
3899                         $logType = 'move_redir';
3900                 } else {
3901                         $moveOverRedirect = false;
3902                         $logType = 'move';
3903                 }
3904
3905                 if ( $createRedirect ) {
3906                         if ( $this->getNamespace() == NS_CATEGORY
3907                                 && !wfMessage( 'category-move-redirect-override' )->inContentLanguage()->isDisabled()
3908                         ) {
3909                                 $redirectContent = new WikitextContent(
3910                                         wfMessage( 'category-move-redirect-override' )
3911                                                 ->params( $nt->getPrefixedText() )->inContentLanguage()->plain() );
3912                         } else {
3913                                 $contentHandler = ContentHandler::getForTitle( $this );
3914                                 $redirectContent = $contentHandler->makeRedirectContent( $nt,
3915                                         wfMessage( 'move-redirect-text' )->inContentLanguage()->plain() );
3916                         }
3917
3918                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3919                 } else {
3920                         $redirectContent = null;
3921                 }
3922
3923                 $logEntry = new ManualLogEntry( 'move', $logType );
3924                 $logEntry->setPerformer( $wgUser );
3925                 $logEntry->setTarget( $this );
3926                 $logEntry->setComment( $reason );
3927                 $logEntry->setParameters( array(
3928                         '4::target' => $nt->getPrefixedText(),
3929                         '5::noredir' => $redirectContent ? '0': '1',
3930                 ) );
3931
3932                 $formatter = LogFormatter::newFromEntry( $logEntry );
3933                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3934                 $comment = $formatter->getPlainActionText();
3935                 if ( $reason ) {
3936                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3937                 }
3938                 # Truncate for whole multibyte characters.
3939                 $comment = $wgContLang->truncate( $comment, 255 );
3940
3941                 $oldid = $this->getArticleID();
3942
3943                 $dbw = wfGetDB( DB_MASTER );
3944
3945                 $newpage = WikiPage::factory( $nt );
3946
3947                 if ( $moveOverRedirect ) {
3948                         $newid = $nt->getArticleID();
3949                         $newcontent = $newpage->getContent();
3950
3951                         # Delete the old redirect. We don't save it to history since
3952                         # by definition if we've got here it's rather uninteresting.
3953                         # We have to remove it so that the next step doesn't trigger
3954                         # a conflict on the unique namespace+title index...
3955                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3956
3957                         $newpage->doDeleteUpdates( $newid, $newcontent );
3958                 }
3959
3960                 # Save a null revision in the page's history notifying of the move
3961                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true, $wgUser );
3962                 if ( !is_object( $nullRevision ) ) {
3963                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3964                 }
3965
3966                 $nullRevision->insertOn( $dbw );
3967
3968                 # Change the name of the target page:
3969                 $dbw->update( 'page',
3970                         /* SET */ array(
3971                                 'page_namespace' => $nt->getNamespace(),
3972                                 'page_title' => $nt->getDBkey(),
3973                         ),
3974                         /* WHERE */ array( 'page_id' => $oldid ),
3975                         __METHOD__
3976                 );
3977
3978                 // clean up the old title before reset article id - bug 45348
3979                 if ( !$redirectContent ) {
3980                         WikiPage::onArticleDelete( $this );
3981                 }
3982
3983                 $this->resetArticleID( 0 ); // 0 == non existing
3984                 $nt->resetArticleID( $oldid );
3985                 $newpage->loadPageData( WikiPage::READ_LOCKING ); // bug 46397
3986
3987                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3988
3989                 wfRunHooks( 'NewRevisionFromEditComplete',
3990                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3991
3992                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3993
3994                 if ( !$moveOverRedirect ) {
3995                         WikiPage::onArticleCreate( $nt );
3996                 }
3997
3998                 # Recreate the redirect, this time in the other direction.
3999                 if ( $redirectContent ) {
4000                         $redirectArticle = WikiPage::factory( $this );
4001                         $redirectArticle->loadFromRow( false, WikiPage::READ_LOCKING ); // bug 46397
4002                         $newid = $redirectArticle->insertOn( $dbw );
4003                         if ( $newid ) { // sanity
4004                                 $this->resetArticleID( $newid );
4005                                 $redirectRevision = new Revision( array(
4006                                         'title' => $this, // for determining the default content model
4007                                         'page' => $newid,
4008                                         'user_text' => $wgUser->getName(),
4009                                         'user' => $wgUser->getId(),
4010                                         'comment' => $comment,
4011                                         'content' => $redirectContent ) );
4012                                 $redirectRevision->insertOn( $dbw );
4013                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
4014
4015                                 wfRunHooks( 'NewRevisionFromEditComplete',
4016                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
4017
4018                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
4019                         }
4020                 }
4021
4022                 # Log the move
4023                 $logid = $logEntry->insert();
4024                 $logEntry->publish( $logid );
4025         }
4026
4027         /**
4028          * Move this page's subpages to be subpages of $nt
4029          *
4030          * @param Title $nt Move target
4031          * @param bool $auth Whether $wgUser's permissions should be checked
4032          * @param string $reason The reason for the move
4033          * @param bool $createRedirect Whether to create redirects from the old subpages to
4034          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
4035          * @return array Array with old page titles as keys, and strings (new page titles) or
4036          *     arrays (errors) as values, or an error array with numeric indices if no pages
4037          *     were moved
4038          */
4039         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
4040                 global $wgMaximumMovedPages;
4041                 // Check permissions
4042                 if ( !$this->userCan( 'move-subpages' ) ) {
4043                         return array( 'cant-move-subpages' );
4044                 }
4045                 // Do the source and target namespaces support subpages?
4046                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4047                         return array( 'namespace-nosubpages',
4048                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
4049                 }
4050                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
4051                         return array( 'namespace-nosubpages',
4052                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
4053                 }
4054
4055                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
4056                 $retval = array();
4057                 $count = 0;
4058                 foreach ( $subpages as $oldSubpage ) {
4059                         $count++;
4060                         if ( $count > $wgMaximumMovedPages ) {
4061                                 $retval[$oldSubpage->getPrefixedText()] =
4062                                                 array( 'movepage-max-pages',
4063                                                         $wgMaximumMovedPages );
4064                                 break;
4065                         }
4066
4067                         // We don't know whether this function was called before
4068                         // or after moving the root page, so check both
4069                         // $this and $nt
4070                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
4071                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
4072                         ) {
4073                                 // When moving a page to a subpage of itself,
4074                                 // don't move it twice
4075                                 continue;
4076                         }
4077                         $newPageName = preg_replace(
4078                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
4079                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
4080                                         $oldSubpage->getDBkey() );
4081                         if ( $oldSubpage->isTalkPage() ) {
4082                                 $newNs = $nt->getTalkPage()->getNamespace();
4083                         } else {
4084                                 $newNs = $nt->getSubjectPage()->getNamespace();
4085                         }
4086                         # Bug 14385: we need makeTitleSafe because the new page names may
4087                         # be longer than 255 characters.
4088                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
4089
4090                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
4091                         if ( $success === true ) {
4092                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
4093                         } else {
4094                                 $retval[$oldSubpage->getPrefixedText()] = $success;
4095                         }
4096                 }
4097                 return $retval;
4098         }
4099
4100         /**
4101          * Checks if this page is just a one-rev redirect.
4102          * Adds lock, so don't use just for light purposes.
4103          *
4104          * @return bool
4105          */
4106         public function isSingleRevRedirect() {
4107                 global $wgContentHandlerUseDB;
4108
4109                 $dbw = wfGetDB( DB_MASTER );
4110
4111                 # Is it a redirect?
4112                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
4113                 if ( $wgContentHandlerUseDB ) {
4114                         $fields[] = 'page_content_model';
4115                 }
4116
4117                 $row = $dbw->selectRow( 'page',
4118                         $fields,
4119                         $this->pageCond(),
4120                         __METHOD__,
4121                         array( 'FOR UPDATE' )
4122                 );
4123                 # Cache some fields we may want
4124                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
4125                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
4126                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
4127                 $this->mContentModel = $row && isset( $row->page_content_model )
4128                         ? strval( $row->page_content_model )
4129                         : false;
4130
4131                 if ( !$this->mRedirect ) {
4132                         return false;
4133                 }
4134                 # Does the article have a history?
4135                 $row = $dbw->selectField( array( 'page', 'revision' ),
4136                         'rev_id',
4137                         array( 'page_namespace' => $this->getNamespace(),
4138                                 'page_title' => $this->getDBkey(),
4139                                 'page_id=rev_page',
4140                                 'page_latest != rev_id'
4141                         ),
4142                         __METHOD__,
4143                         array( 'FOR UPDATE' )
4144                 );
4145                 # Return true if there was no history
4146                 return ( $row === false );
4147         }
4148
4149         /**
4150          * Checks if $this can be moved to a given Title
4151          * - Selects for update, so don't call it unless you mean business
4152          *
4153          * @param Title $nt The new title to check
4154          * @return bool
4155          */
4156         public function isValidMoveTarget( $nt ) {
4157                 # Is it an existing file?
4158                 if ( $nt->getNamespace() == NS_FILE ) {
4159                         $file = wfLocalFile( $nt );
4160                         if ( $file->exists() ) {
4161                                 wfDebug( __METHOD__ . ": file exists\n" );
4162                                 return false;
4163                         }
4164                 }
4165                 # Is it a redirect with no history?
4166                 if ( !$nt->isSingleRevRedirect() ) {
4167                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
4168                         return false;
4169                 }
4170                 # Get the article text
4171                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
4172                 if ( !is_object( $rev ) ) {
4173                         return false;
4174                 }
4175                 $content = $rev->getContent();
4176                 # Does the redirect point to the source?
4177                 # Or is it a broken self-redirect, usually caused by namespace collisions?
4178                 $redirTitle = $content ? $content->getRedirectTarget() : null;
4179
4180                 if ( $redirTitle ) {
4181                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
4182                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
4183                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
4184                                 return false;
4185                         } else {
4186                                 return true;
4187                         }
4188                 } else {
4189                         # Fail safe (not a redirect after all. strange.)
4190                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
4191                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
4192                         return false;
4193                 }
4194         }
4195
4196         /**
4197          * Get categories to which this Title belongs and return an array of
4198          * categories' names.
4199          *
4200          * @return array Array of parents in the form:
4201          *        $parent => $currentarticle
4202          */
4203         public function getParentCategories() {
4204                 global $wgContLang;
4205
4206                 $data = array();
4207
4208                 $titleKey = $this->getArticleID();
4209
4210                 if ( $titleKey === 0 ) {
4211                         return $data;
4212                 }
4213
4214                 $dbr = wfGetDB( DB_SLAVE );
4215
4216                 $res = $dbr->select(
4217                         'categorylinks',
4218                         'cl_to',
4219                         array( 'cl_from' => $titleKey ),
4220                         __METHOD__
4221                 );
4222
4223                 if ( $res->numRows() > 0 ) {
4224                         foreach ( $res as $row ) {
4225                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
4226                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4227                         }
4228                 }
4229                 return $data;
4230         }
4231
4232         /**
4233          * Get a tree of parent categories
4234          *
4235          * @param array $children Array with the children in the keys, to check for circular refs
4236          * @return array Tree of parent categories
4237          */
4238         public function getParentCategoryTree( $children = array() ) {
4239                 $stack = array();
4240                 $parents = $this->getParentCategories();
4241
4242                 if ( $parents ) {
4243                         foreach ( $parents as $parent => $current ) {
4244                                 if ( array_key_exists( $parent, $children ) ) {
4245                                         # Circular reference
4246                                         $stack[$parent] = array();
4247                                 } else {
4248                                         $nt = Title::newFromText( $parent );
4249                                         if ( $nt ) {
4250                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4251                                         }
4252                                 }
4253                         }
4254                 }
4255
4256                 return $stack;
4257         }
4258
4259         /**
4260          * Get an associative array for selecting this title from
4261          * the "page" table
4262          *
4263          * @return array Array suitable for the $where parameter of DB::select()
4264          */
4265         public function pageCond() {
4266                 if ( $this->mArticleID > 0 ) {
4267                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4268                         return array( 'page_id' => $this->mArticleID );
4269                 } else {
4270                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4271                 }
4272         }
4273
4274         /**
4275          * Get the revision ID of the previous revision
4276          *
4277          * @param int $revId Revision ID. Get the revision that was before this one.
4278          * @param int $flags Title::GAID_FOR_UPDATE
4279          * @return int|bool Old revision ID, or false if none exists
4280          */
4281         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4282                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4283                 $revId = $db->selectField( 'revision', 'rev_id',
4284                         array(
4285                                 'rev_page' => $this->getArticleID( $flags ),
4286                                 'rev_id < ' . intval( $revId )
4287                         ),
4288                         __METHOD__,
4289                         array( 'ORDER BY' => 'rev_id DESC' )
4290                 );
4291
4292                 if ( $revId === false ) {
4293                         return false;
4294                 } else {
4295                         return intval( $revId );
4296                 }
4297         }
4298
4299         /**
4300          * Get the revision ID of the next revision
4301          *
4302          * @param int $revId Revision ID. Get the revision that was after this one.
4303          * @param int $flags Title::GAID_FOR_UPDATE
4304          * @return int|bool Next revision ID, or false if none exists
4305          */
4306         public function getNextRevisionID( $revId, $flags = 0 ) {
4307                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4308                 $revId = $db->selectField( 'revision', 'rev_id',
4309                         array(
4310                                 'rev_page' => $this->getArticleID( $flags ),
4311                                 'rev_id > ' . intval( $revId )
4312                         ),
4313                         __METHOD__,
4314                         array( 'ORDER BY' => 'rev_id' )
4315                 );
4316
4317                 if ( $revId === false ) {
4318                         return false;
4319                 } else {
4320                         return intval( $revId );
4321                 }
4322         }
4323
4324         /**
4325          * Get the first revision of the page
4326          *
4327          * @param int $flags Title::GAID_FOR_UPDATE
4328          * @return Revision|null If page doesn't exist
4329          */
4330         public function getFirstRevision( $flags = 0 ) {
4331                 $pageId = $this->getArticleID( $flags );
4332                 if ( $pageId ) {
4333                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4334                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4335                                 array( 'rev_page' => $pageId ),
4336                                 __METHOD__,
4337                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4338                         );
4339                         if ( $row ) {
4340                                 return new Revision( $row );
4341                         }
4342                 }
4343                 return null;
4344         }
4345
4346         /**
4347          * Get the oldest revision timestamp of this page
4348          *
4349          * @param int $flags Title::GAID_FOR_UPDATE
4350          * @return string MW timestamp
4351          */
4352         public function getEarliestRevTime( $flags = 0 ) {
4353                 $rev = $this->getFirstRevision( $flags );
4354                 return $rev ? $rev->getTimestamp() : null;
4355         }
4356
4357         /**
4358          * Check if this is a new page
4359          *
4360          * @return bool
4361          */
4362         public function isNewPage() {
4363                 $dbr = wfGetDB( DB_SLAVE );
4364                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4365         }
4366
4367         /**
4368          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4369          *
4370          * @return bool
4371          */
4372         public function isBigDeletion() {
4373                 global $wgDeleteRevisionsLimit;
4374
4375                 if ( !$wgDeleteRevisionsLimit ) {
4376                         return false;
4377                 }
4378
4379                 $revCount = $this->estimateRevisionCount();
4380                 return $revCount > $wgDeleteRevisionsLimit;
4381         }
4382
4383         /**
4384          * Get the  approximate revision count of this page.
4385          *
4386          * @return int
4387          */
4388         public function estimateRevisionCount() {
4389                 if ( !$this->exists() ) {
4390                         return 0;
4391                 }
4392
4393                 if ( $this->mEstimateRevisions === null ) {
4394                         $dbr = wfGetDB( DB_SLAVE );
4395                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4396                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4397                 }
4398
4399                 return $this->mEstimateRevisions;
4400         }
4401
4402         /**
4403          * Get the number of revisions between the given revision.
4404          * Used for diffs and other things that really need it.
4405          *
4406          * @param int|Revision $old Old revision or rev ID (first before range)
4407          * @param int|Revision $new New revision or rev ID (first after range)
4408          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4409          * @return int Number of revisions between these revisions.
4410          */
4411         public function countRevisionsBetween( $old, $new, $max = null ) {
4412                 if ( !( $old instanceof Revision ) ) {
4413                         $old = Revision::newFromTitle( $this, (int)$old );
4414                 }
4415                 if ( !( $new instanceof Revision ) ) {
4416                         $new = Revision::newFromTitle( $this, (int)$new );
4417                 }
4418                 if ( !$old || !$new ) {
4419                         return 0; // nothing to compare
4420                 }
4421                 $dbr = wfGetDB( DB_SLAVE );
4422                 $conds = array(
4423                         'rev_page' => $this->getArticleID(),
4424                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4425                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4426                 );
4427                 if ( $max !== null ) {
4428                         $res = $dbr->select( 'revision', '1',
4429                                 $conds,
4430                                 __METHOD__,
4431                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4432                         );
4433                         return $res->numRows();
4434                 } else {
4435                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4436                 }
4437         }
4438
4439         /**
4440          * Get the authors between the given revisions or revision IDs.
4441          * Used for diffs and other things that really need it.
4442          *
4443          * @since 1.23
4444          *
4445          * @param int|Revision $old Old revision or rev ID (first before range by default)
4446          * @param int|Revision $new New revision or rev ID (first after range by default)
4447          * @param int $limit Maximum number of authors
4448          * @param string|array $options (Optional): Single option, or an array of options:
4449          *     'include_old' Include $old in the range; $new is excluded.
4450          *     'include_new' Include $new in the range; $old is excluded.
4451          *     'include_both' Include both $old and $new in the range.
4452          *     Unknown option values are ignored.
4453          * @return array|null Names of revision authors in the range; null if not both revisions exist
4454          */
4455         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4456                 if ( !( $old instanceof Revision ) ) {
4457                         $old = Revision::newFromTitle( $this, (int)$old );
4458                 }
4459                 if ( !( $new instanceof Revision ) ) {
4460                         $new = Revision::newFromTitle( $this, (int)$new );
4461                 }
4462                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4463                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4464                 // in the sanity check below?
4465                 if ( !$old || !$new ) {
4466                         return null; // nothing to compare
4467                 }
4468                 $authors = array();
4469                 $old_cmp = '>';
4470                 $new_cmp = '<';
4471                 $options = (array)$options;
4472                 if ( in_array( 'include_old', $options ) ) {
4473                         $old_cmp = '>=';
4474                 }
4475                 if ( in_array( 'include_new', $options ) ) {
4476                         $new_cmp = '<=';
4477                 }
4478                 if ( in_array( 'include_both', $options ) ) {
4479                         $old_cmp = '>=';
4480                         $new_cmp = '<=';
4481                 }
4482                 // No DB query needed if $old and $new are the same or successive revisions:
4483                 if ( $old->getId() === $new->getId() ) {
4484                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? array() : array( $old->getRawUserText() );
4485                 } elseif ( $old->getId() === $new->getParentId() ) {
4486                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4487                                 $authors[] = $old->getRawUserText();
4488                                 if ( $old->getRawUserText() != $new->getRawUserText() ) {
4489                                         $authors[] = $new->getRawUserText();
4490                                 }
4491                         } elseif ( $old_cmp === '>=' ) {
4492                                 $authors[] = $old->getRawUserText();
4493                         } elseif ( $new_cmp === '<=' ) {
4494                                 $authors[] = $new->getRawUserText();
4495                         }
4496                         return $authors;
4497                 }
4498                 $dbr = wfGetDB( DB_SLAVE );
4499                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4500                         array(
4501                                 'rev_page' => $this->getArticleID(),
4502                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4503                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4504                         ), __METHOD__,
4505                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4506                 );
4507                 foreach ( $res as $row ) {
4508                         $authors[] = $row->rev_user_text;
4509                 }
4510                 return $authors;
4511         }
4512
4513         /**
4514          * Get the number of authors between the given revisions or revision IDs.
4515          * Used for diffs and other things that really need it.
4516          *
4517          * @param int|Revision $old Old revision or rev ID (first before range by default)
4518          * @param int|Revision $new New revision or rev ID (first after range by default)
4519          * @param int $limit Maximum number of authors
4520          * @param string|array $options (Optional): Single option, or an array of options:
4521          *     'include_old' Include $old in the range; $new is excluded.
4522          *     'include_new' Include $new in the range; $old is excluded.
4523          *     'include_both' Include both $old and $new in the range.
4524          *     Unknown option values are ignored.
4525          * @return int Number of revision authors in the range; zero if not both revisions exist
4526          */
4527         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4528                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4529                 return $authors ? count( $authors ) : 0;
4530         }
4531
4532         /**
4533          * Compare with another title.
4534          *
4535          * @param Title $title
4536          * @return bool
4537          */
4538         public function equals( Title $title ) {
4539                 // Note: === is necessary for proper matching of number-like titles.
4540                 return $this->getInterwiki() === $title->getInterwiki()
4541                         && $this->getNamespace() == $title->getNamespace()
4542                         && $this->getDBkey() === $title->getDBkey();
4543         }
4544
4545         /**
4546          * Check if this title is a subpage of another title
4547          *
4548          * @param Title $title
4549          * @return bool
4550          */
4551         public function isSubpageOf( Title $title ) {
4552                 return $this->getInterwiki() === $title->getInterwiki()
4553                         && $this->getNamespace() == $title->getNamespace()
4554                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4555         }
4556
4557         /**
4558          * Check if page exists.  For historical reasons, this function simply
4559          * checks for the existence of the title in the page table, and will
4560          * thus return false for interwiki links, special pages and the like.
4561          * If you want to know if a title can be meaningfully viewed, you should
4562          * probably call the isKnown() method instead.
4563          *
4564          * @return bool
4565          */
4566         public function exists() {
4567                 return $this->getArticleID() != 0;
4568         }
4569
4570         /**
4571          * Should links to this title be shown as potentially viewable (i.e. as
4572          * "bluelinks"), even if there's no record by this title in the page
4573          * table?
4574          *
4575          * This function is semi-deprecated for public use, as well as somewhat
4576          * misleadingly named.  You probably just want to call isKnown(), which
4577          * calls this function internally.
4578          *
4579          * (ISSUE: Most of these checks are cheap, but the file existence check
4580          * can potentially be quite expensive.  Including it here fixes a lot of
4581          * existing code, but we might want to add an optional parameter to skip
4582          * it and any other expensive checks.)
4583          *
4584          * @return bool
4585          */
4586         public function isAlwaysKnown() {
4587                 $isKnown = null;
4588
4589                 /**
4590                  * Allows overriding default behavior for determining if a page exists.
4591                  * If $isKnown is kept as null, regular checks happen. If it's
4592                  * a boolean, this value is returned by the isKnown method.
4593                  *
4594                  * @since 1.20
4595                  *
4596                  * @param Title $title
4597                  * @param bool|null $isKnown
4598                  */
4599                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4600
4601                 if ( !is_null( $isKnown ) ) {
4602                         return $isKnown;
4603                 }
4604
4605                 if ( $this->isExternal() ) {
4606                         return true;  // any interwiki link might be viewable, for all we know
4607                 }
4608
4609                 switch ( $this->mNamespace ) {
4610                         case NS_MEDIA:
4611                         case NS_FILE:
4612                                 // file exists, possibly in a foreign repo
4613                                 return (bool)wfFindFile( $this );
4614                         case NS_SPECIAL:
4615                                 // valid special page
4616                                 return SpecialPageFactory::exists( $this->getDBkey() );
4617                         case NS_MAIN:
4618                                 // selflink, possibly with fragment
4619                                 return $this->mDbkeyform == '';
4620                         case NS_MEDIAWIKI:
4621                                 // known system message
4622                                 return $this->hasSourceText() !== false;
4623                         default:
4624                                 return false;
4625                 }
4626         }
4627
4628         /**
4629          * Does this title refer to a page that can (or might) be meaningfully
4630          * viewed?  In particular, this function may be used to determine if
4631          * links to the title should be rendered as "bluelinks" (as opposed to
4632          * "redlinks" to non-existent pages).
4633          * Adding something else to this function will cause inconsistency
4634          * since LinkHolderArray calls isAlwaysKnown() and does its own
4635          * page existence check.
4636          *
4637          * @return bool
4638          */
4639         public function isKnown() {
4640                 return $this->isAlwaysKnown() || $this->exists();
4641         }
4642
4643         /**
4644          * Does this page have source text?
4645          *
4646          * @return bool
4647          */
4648         public function hasSourceText() {
4649                 if ( $this->exists() ) {
4650                         return true;
4651                 }
4652
4653                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4654                         // If the page doesn't exist but is a known system message, default
4655                         // message content will be displayed, same for language subpages-
4656                         // Use always content language to avoid loading hundreds of languages
4657                         // to get the link color.
4658                         global $wgContLang;
4659                         list( $name, ) = MessageCache::singleton()->figureMessage(
4660                                 $wgContLang->lcfirst( $this->getText() )
4661                         );
4662                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4663                         return $message->exists();
4664                 }
4665
4666                 return false;
4667         }
4668
4669         /**
4670          * Get the default message text or false if the message doesn't exist
4671          *
4672          * @return string|bool
4673          */
4674         public function getDefaultMessageText() {
4675                 global $wgContLang;
4676
4677                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4678                         return false;
4679                 }
4680
4681                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4682                         $wgContLang->lcfirst( $this->getText() )
4683                 );
4684                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4685
4686                 if ( $message->exists() ) {
4687                         return $message->plain();
4688                 } else {
4689                         return false;
4690                 }
4691         }
4692
4693         /**
4694          * Updates page_touched for this page; called from LinksUpdate.php
4695          *
4696          * @return bool True if the update succeeded
4697          */
4698         public function invalidateCache() {
4699                 if ( wfReadOnly() ) {
4700                         return false;
4701                 }
4702
4703                 if ( $this->mArticleID === 0 ) {
4704                         return true; // avoid gap locking if we know it's not there
4705                 }
4706
4707                 $method = __METHOD__;
4708                 $dbw = wfGetDB( DB_MASTER );
4709                 $conds = $this->pageCond();
4710                 $dbw->onTransactionIdle( function() use ( $dbw, $conds, $method ) {
4711                         $dbw->update(
4712                                 'page',
4713                                 array( 'page_touched' => $dbw->timestamp() ),
4714                                 $conds,
4715                                 $method
4716                         );
4717                 } );
4718
4719                 return true;
4720         }
4721
4722         /**
4723          * Update page_touched timestamps and send squid purge messages for
4724          * pages linking to this title. May be sent to the job queue depending
4725          * on the number of links. Typically called on create and delete.
4726          */
4727         public function touchLinks() {
4728                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4729                 $u->doUpdate();
4730
4731                 if ( $this->getNamespace() == NS_CATEGORY ) {
4732                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4733                         $u->doUpdate();
4734                 }
4735         }
4736
4737         /**
4738          * Get the last touched timestamp
4739          *
4740          * @param DatabaseBase $db Optional db
4741          * @return string Last-touched timestamp
4742          */
4743         public function getTouched( $db = null ) {
4744                 if ( $db === null ) {
4745                         $db = wfGetDB( DB_SLAVE );
4746                 }
4747                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4748                 return $touched;
4749         }
4750
4751         /**
4752          * Get the timestamp when this page was updated since the user last saw it.
4753          *
4754          * @param User $user
4755          * @return string|null
4756          */
4757         public function getNotificationTimestamp( $user = null ) {
4758                 global $wgUser, $wgShowUpdatedMarker;
4759                 // Assume current user if none given
4760                 if ( !$user ) {
4761                         $user = $wgUser;
4762                 }
4763                 // Check cache first
4764                 $uid = $user->getId();
4765                 // avoid isset here, as it'll return false for null entries
4766                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4767                         return $this->mNotificationTimestamp[$uid];
4768                 }
4769                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4770                         $this->mNotificationTimestamp[$uid] = false;
4771                         return $this->mNotificationTimestamp[$uid];
4772                 }
4773                 // Don't cache too much!
4774                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4775                         $this->mNotificationTimestamp = array();
4776                 }
4777                 $dbr = wfGetDB( DB_SLAVE );
4778                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4779                         'wl_notificationtimestamp',
4780                         array(
4781                                 'wl_user' => $user->getId(),
4782                                 'wl_namespace' => $this->getNamespace(),
4783                                 'wl_title' => $this->getDBkey(),
4784                         ),
4785                         __METHOD__
4786                 );
4787                 return $this->mNotificationTimestamp[$uid];
4788         }
4789
4790         /**
4791          * Generate strings used for xml 'id' names in monobook tabs
4792          *
4793          * @param string $prepend Defaults to 'nstab-'
4794          * @return string XML 'id' name
4795          */
4796         public function getNamespaceKey( $prepend = 'nstab-' ) {
4797                 global $wgContLang;
4798                 // Gets the subject namespace if this title
4799                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4800                 // Checks if canonical namespace name exists for namespace
4801                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4802                         // Uses canonical namespace name
4803                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4804                 } else {
4805                         // Uses text of namespace
4806                         $namespaceKey = $this->getSubjectNsText();
4807                 }
4808                 // Makes namespace key lowercase
4809                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4810                 // Uses main
4811                 if ( $namespaceKey == '' ) {
4812                         $namespaceKey = 'main';
4813                 }
4814                 // Changes file to image for backwards compatibility
4815                 if ( $namespaceKey == 'file' ) {
4816                         $namespaceKey = 'image';
4817                 }
4818                 return $prepend . $namespaceKey;
4819         }
4820
4821         /**
4822          * Get all extant redirects to this Title
4823          *
4824          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4825          * @return Title[] Array of Title redirects to this title
4826          */
4827         public function getRedirectsHere( $ns = null ) {
4828                 $redirs = array();
4829
4830                 $dbr = wfGetDB( DB_SLAVE );
4831                 $where = array(
4832                         'rd_namespace' => $this->getNamespace(),
4833                         'rd_title' => $this->getDBkey(),
4834                         'rd_from = page_id'
4835                 );
4836                 if ( $this->isExternal() ) {
4837                         $where['rd_interwiki'] = $this->getInterwiki();
4838                 } else {
4839                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4840                 }
4841                 if ( !is_null( $ns ) ) {
4842                         $where['page_namespace'] = $ns;
4843                 }
4844
4845                 $res = $dbr->select(
4846                         array( 'redirect', 'page' ),
4847                         array( 'page_namespace', 'page_title' ),
4848                         $where,
4849                         __METHOD__
4850                 );
4851
4852                 foreach ( $res as $row ) {
4853                         $redirs[] = self::newFromRow( $row );
4854                 }
4855                 return $redirs;
4856         }
4857
4858         /**
4859          * Check if this Title is a valid redirect target
4860          *
4861          * @return bool
4862          */
4863         public function isValidRedirectTarget() {
4864                 global $wgInvalidRedirectTargets;
4865
4866                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4867                 if ( $this->isSpecial( 'Userlogout' ) ) {
4868                         return false;
4869                 }
4870
4871                 foreach ( $wgInvalidRedirectTargets as $target ) {
4872                         if ( $this->isSpecial( $target ) ) {
4873                                 return false;
4874                         }
4875                 }
4876
4877                 return true;
4878         }
4879
4880         /**
4881          * Get a backlink cache object
4882          *
4883          * @return BacklinkCache
4884          */
4885         public function getBacklinkCache() {
4886                 return BacklinkCache::get( $this );
4887         }
4888
4889         /**
4890          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4891          *
4892          * @return bool
4893          */
4894         public function canUseNoindex() {
4895                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4896
4897                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4898                         ? $wgContentNamespaces
4899                         : $wgExemptFromUserRobotsControl;
4900
4901                 return !in_array( $this->mNamespace, $bannedNamespaces );
4902
4903         }
4904
4905         /**
4906          * Returns the raw sort key to be used for categories, with the specified
4907          * prefix.  This will be fed to Collation::getSortKey() to get a
4908          * binary sortkey that can be used for actual sorting.
4909          *
4910          * @param string $prefix The prefix to be used, specified using
4911          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4912          *   prefix.
4913          * @return string
4914          */
4915         public function getCategorySortkey( $prefix = '' ) {
4916                 $unprefixed = $this->getText();
4917
4918                 // Anything that uses this hook should only depend
4919                 // on the Title object passed in, and should probably
4920                 // tell the users to run updateCollations.php --force
4921                 // in order to re-sort existing category relations.
4922                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4923                 if ( $prefix !== '' ) {
4924                         # Separate with a line feed, so the unprefixed part is only used as
4925                         # a tiebreaker when two pages have the exact same prefix.
4926                         # In UCA, tab is the only character that can sort above LF
4927                         # so we strip both of them from the original prefix.
4928                         $prefix = strtr( $prefix, "\n\t", '  ' );
4929                         return "$prefix\n$unprefixed";
4930                 }
4931                 return $unprefixed;
4932         }
4933
4934         /**
4935          * Get the language in which the content of this page is written in
4936          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4937          * e.g. $wgLang (such as special pages, which are in the user language).
4938          *
4939          * @since 1.18
4940          * @return Language
4941          */
4942         public function getPageLanguage() {
4943                 global $wgLang, $wgLanguageCode;
4944                 wfProfileIn( __METHOD__ );
4945                 if ( $this->isSpecialPage() ) {
4946                         // special pages are in the user language
4947                         wfProfileOut( __METHOD__ );
4948                         return $wgLang;
4949                 }
4950
4951                 // Checking if DB language is set
4952                 if ( $this->mDbPageLanguage ) {
4953                         wfProfileOut( __METHOD__ );
4954                         return wfGetLangObj( $this->mDbPageLanguage );
4955                 }
4956
4957                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4958                         // Note that this may depend on user settings, so the cache should
4959                         // be only per-request.
4960                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4961                         // content to determine the page language!
4962                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4963                         // tests.
4964                         $contentHandler = ContentHandler::getForTitle( $this );
4965                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4966                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4967                 } else {
4968                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4969                 }
4970
4971                 wfProfileOut( __METHOD__ );
4972                 return $langObj;
4973         }
4974
4975         /**
4976          * Get the language in which the content of this page is written when
4977          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4978          * e.g. $wgLang (such as special pages, which are in the user language).
4979          *
4980          * @since 1.20
4981          * @return Language
4982          */
4983         public function getPageViewLanguage() {
4984                 global $wgLang;
4985
4986                 if ( $this->isSpecialPage() ) {
4987                         // If the user chooses a variant, the content is actually
4988                         // in a language whose code is the variant code.
4989                         $variant = $wgLang->getPreferredVariant();
4990                         if ( $wgLang->getCode() !== $variant ) {
4991                                 return Language::factory( $variant );
4992                         }
4993
4994                         return $wgLang;
4995                 }
4996
4997                 // @note Can't be cached persistently, depends on user settings.
4998                 // @note ContentHandler::getPageViewLanguage() may need to load the
4999                 //   content to determine the page language!
5000                 $contentHandler = ContentHandler::getForTitle( $this );
5001                 $pageLang = $contentHandler->getPageViewLanguage( $this );
5002                 return $pageLang;
5003         }
5004
5005         /**
5006          * Get a list of rendered edit notices for this page.
5007          *
5008          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
5009          * they will already be wrapped in paragraphs.
5010          *
5011          * @since 1.21
5012          * @param int $oldid Revision ID that's being edited
5013          * @return array
5014          */
5015         public function getEditNotices( $oldid = 0 ) {
5016                 $notices = array();
5017
5018                 # Optional notices on a per-namespace and per-page basis
5019                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
5020                 $editnotice_ns_message = wfMessage( $editnotice_ns );
5021                 if ( $editnotice_ns_message->exists() ) {
5022                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
5023                 }
5024                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
5025                         $parts = explode( '/', $this->getDBkey() );
5026                         $editnotice_base = $editnotice_ns;
5027                         while ( count( $parts ) > 0 ) {
5028                                 $editnotice_base .= '-' . array_shift( $parts );
5029                                 $editnotice_base_msg = wfMessage( $editnotice_base );
5030                                 if ( $editnotice_base_msg->exists() ) {
5031                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
5032                                 }
5033                         }
5034                 } else {
5035                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
5036                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
5037                         $editnoticeMsg = wfMessage( $editnoticeText );
5038                         if ( $editnoticeMsg->exists() ) {
5039                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
5040                         }
5041                 }
5042
5043                 wfRunHooks( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
5044                 return $notices;
5045         }
5046 }