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 class Title {
  34         /** @var MapCacheLRU */
  35         static private $titleCache = null;
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  49
  50         /**
  51          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         /** @var string Text form (spaces not underscores) of the main part */
  58         public $mTextform = '';
  59
  60         /** @var string URL-encoded form of the main part */
  61         public $mUrlform = '';
  62
  63         /** @var string Main part with underscores */
  64         public $mDbkeyform = '';
  65
  66         /** @var string Database key with the initial letter in the case specified by the user */
  67         protected $mUserCaseDBKey;
  68
  69         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  70         public $mNamespace = NS_MAIN;
  71
  72         /** @var string Interwiki prefix */
  73         public $mInterwiki = '';
  74
  75         /** @var bool Was this Title created from a string with a local interwiki prefix? */
  76         private $mLocalInterwiki = false;
  77
  78         /** @var string Title fragment (i.e. the bit after the #) */
  79         public $mFragment = '';
  80
  81         /** @var int Article ID, fetched from the link cache on demand */
  82         public $mArticleID = -1;
  83
  84         /** @var bool|int ID of most recent revision */
  85         protected $mLatestID = false;
  86
  87         /**
  88          * @var bool|string ID of the page's content model, i.e. one of the
  89          *   CONTENT_MODEL_XXX constants
  90          */
  91         public $mContentModel = false;
  92
  93         /** @var int Estimated number of revisions; null of not loaded */
  94         private $mEstimateRevisions;
  95
  96         /** @var array Array of groups allowed to edit this article */
  97         public $mRestrictions = array();
  98
  99         /** @var string|bool */
 100         protected $mOldRestrictions = false;
 101
 102         /** @var bool Cascade restrictions on this page to included templates and images? */
 103         public $mCascadeRestriction;
 104
 105         /** Caching the results of getCascadeProtectionSources */
 106         public $mCascadingRestrictions;
 107
 108         /** @var array When do the restrictions on this page expire? */
 109         protected $mRestrictionsExpiry = array();
 110
 111         /** @var bool Are cascading restrictions in effect on this page? */
 112         protected $mHasCascadingRestrictions;
 113
 114         /** @var array Where are the cascading restrictions coming from on this page? */
 115         public $mCascadeSources;
 116
 117         /** @var bool Boolean for initialisation on demand */
 118         public $mRestrictionsLoaded = false;
 119
 120         /** @var string Text form including namespace/interwiki, initialised on demand */
 121         protected $mPrefixedText = null;
 122
 123         /** @var mixed Cached value for getTitleProtection (create protection) */
 124         public $mTitleProtection;
 125
 126         /**
 127          * @var int Namespace index when there is no namespace. Don't change the
 128          *   following default, NS_MAIN is hardcoded in several places. See bug 696.
 129          *   Zero except in {{transclusion}} tags.
 130          */
 131         public $mDefaultNamespace = NS_MAIN;
 132
 133         /**
 134          * @var bool Is $wgUser watching this page? null if unfilled, accessed
 135          * through userIsWatching()
 136          */
 137         protected $mWatched = null;
 138
 139         /** @var int The page length, 0 for special pages */
 140         protected $mLength = -1;
 141
 142         /** @var null Is the article at this title a redirect? */
 143         public $mRedirect = null;
 144
 145         /** @var array Associative array of user ID -> timestamp/false */
 146         private $mNotificationTimestamp = array();
 147
 148         /** @var bool Whether a page has any subpages */
 149         private $mHasSubpages;
 150
 151         /** @var bool The (string) language code of the page's language and content code. */
 152         private $mPageLanguage = false;
 153
 154         /** @var string The page language code from the database */
 155         private $mDbPageLanguage = null;
 156
 157         /** @var TitleValue A corresponding TitleValue object */
 158         private $mTitleValue = null;
 159
 160         /** @var bool Would deleting this page be a big deletion? */
 161         private $mIsBigDeletion = null;
 162         // @}
 163
 164         /**
 165          * B/C kludge: provide a TitleParser for use by Title.
 166          * Ideally, Title would have no methods that need this.
 167          * Avoid usage of this singleton by using TitleValue
 168          * and the associated services when possible.
 169          *
 170          * @return TitleParser
 171          */
 172         private static function getTitleParser() {
 173                 global $wgContLang, $wgLocalInterwikis;
 174
 175                 static $titleCodec = null;
 176                 static $titleCodecFingerprint = null;
 177
 178                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 179                 // make sure we are using the right one. To detect changes over the course
 180                 // of a request, we remember a fingerprint of the config used to create the
 181                 // codec singleton, and re-create it if the fingerprint doesn't match.
 182                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . join( '+', $wgLocalInterwikis );
 183
 184                 if ( $fingerprint !== $titleCodecFingerprint ) {
 185                         $titleCodec = null;
 186                 }
 187
 188                 if ( !$titleCodec ) {
 189                         $titleCodec = new MediaWikiTitleCodec(
 190                                 $wgContLang,
 191                                 GenderCache::singleton(),
 192                                 $wgLocalInterwikis
 193                         );
 194                         $titleCodecFingerprint = $fingerprint;
 195                 }
 196
 197                 return $titleCodec;
 198         }
 199
 200         /**
 201          * B/C kludge: provide a TitleParser for use by Title.
 202          * Ideally, Title would have no methods that need this.
 203          * Avoid usage of this singleton by using TitleValue
 204          * and the associated services when possible.
 205          *
 206          * @return TitleFormatter
 207          */
 208         private static function getTitleFormatter() {
 209                 //NOTE: we know that getTitleParser() returns a MediaWikiTitleCodec,
 210                 //      which implements TitleFormatter.
 211                 return self::getTitleParser();
 212         }
 213
 214         function __construct() {
 215         }
 216
 217         /**
 218          * Create a new Title from a prefixed DB key
 219          *
 220          * @param string $key The database key, which has underscores
 221          *      instead of spaces, possibly including namespace and
 222          *      interwiki prefixes
 223          * @return Title|null Title, or null on an error
 224          */
 225         public static function newFromDBkey( $key ) {
 226                 $t = new Title();
 227                 $t->mDbkeyform = $key;
 228                 if ( $t->secureAndSplit() ) {
 229                         return $t;
 230                 } else {
 231                         return null;
 232                 }
 233         }
 234
 235         /**
 236          * Create a new Title from a TitleValue
 237          *
 238          * @param TitleValue $titleValue Assumed to be safe.
 239          *
 240          * @return Title
 241          */
 242         public static function newFromTitleValue( TitleValue $titleValue ) {
 243                 return self::makeTitle(
 244                         $titleValue->getNamespace(),
 245                         $titleValue->getText(),
 246                         $titleValue->getFragment() );
 247         }
 248
 249         /**
 250          * Create a new Title from text, such as what one would find in a link. De-
 251          * codes any HTML entities in the text.
 252          *
 253          * @param string $text The link text; spaces, prefixes, and an
 254          *   initial ':' indicating the main namespace are accepted.
 255          * @param int $defaultNamespace The namespace to use if none is specified
 256          *   by a prefix.  If you want to force a specific namespace even if
 257          *   $text might begin with a namespace prefix, use makeTitle() or
 258          *   makeTitleSafe().
 259          * @throws InvalidArgumentException
 260          * @return Title|null Title or null on an error.
 261          */
 262         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 263                 if ( is_object( $text ) ) {
 264                         throw new InvalidArgumentException( '$text must be a string.' );
 265                 } elseif ( !is_string( $text ) ) {
 266                         wfWarn( __METHOD__ . ': $text must be a string. This will throw an InvalidArgumentException in future.', 2 );
 267                 }
 268
 269                 $cache = self::getTitleCache();
 270
 271                 /**
 272                  * Wiki pages often contain multiple links to the same page.
 273                  * Title normalization and parsing can become expensive on
 274                  * pages with many links, so we can save a little time by
 275                  * caching them.
 276                  *
 277                  * In theory these are value objects and won't get changed...
 278                  */
 279                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 280                         return $cache->get( $text );
 281                 }
 282
 283                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 284                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 285
 286                 $t = new Title();
 287                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 288                 $t->mDefaultNamespace = intval( $defaultNamespace );
 289
 290                 if ( $t->secureAndSplit() ) {
 291                         if ( $defaultNamespace == NS_MAIN ) {
 292                                 $cache->set( $text, $t );
 293                         }
 294                         return $t;
 295                 } else {
 296                         return null;
 297                 }
 298         }
 299
 300         /**
 301          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 302          *
 303          * Example of wrong and broken code:
 304          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 305          *
 306          * Example of right code:
 307          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 308          *
 309          * Create a new Title from URL-encoded text. Ensures that
 310          * the given title's length does not exceed the maximum.
 311          *
 312          * @param string $url The title, as might be taken from a URL
 313          * @return Title|null The new object, or null on an error
 314          */
 315         public static function newFromURL( $url ) {
 316                 $t = new Title();
 317
 318                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 319                 # but some URLs used it as a space replacement and they still come
 320                 # from some external search tools.
 321                 if ( strpos( self::legalChars(), '+' ) === false ) {
 322                         $url = str_replace( '+', ' ', $url );
 323                 }
 324
 325                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 326                 if ( $t->secureAndSplit() ) {
 327                         return $t;
 328                 } else {
 329                         return null;
 330                 }
 331         }
 332
 333         /**
 334          * @return MapCacheLRU
 335          */
 336         private static function getTitleCache() {
 337                 if ( self::$titleCache == null ) {
 338                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 339                 }
 340                 return self::$titleCache;
 341         }
 342
 343         /**
 344          * Returns a list of fields that are to be selected for initializing Title
 345          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 346          * whether to include page_content_model.
 347          *
 348          * @return array
 349          */
 350         protected static function getSelectFields() {
 351                 global $wgContentHandlerUseDB;
 352
 353                 $fields = array(
 354                         'page_namespace', 'page_title', 'page_id',
 355                         'page_len', 'page_is_redirect', 'page_latest',
 356                 );
 357
 358                 if ( $wgContentHandlerUseDB ) {
 359                         $fields[] = 'page_content_model';
 360                 }
 361
 362                 return $fields;
 363         }
 364
 365         /**
 366          * Create a new Title from an article ID
 367          *
 368          * @param int $id The page_id corresponding to the Title to create
 369          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 370          * @return Title|null The new object, or null on an error
 371          */
 372         public static function newFromID( $id, $flags = 0 ) {
 373                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 374                 $row = $db->selectRow(
 375                         'page',
 376                         self::getSelectFields(),
 377                         array( 'page_id' => $id ),
 378                         __METHOD__
 379                 );
 380                 if ( $row !== false ) {
 381                         $title = Title::newFromRow( $row );
 382                 } else {
 383                         $title = null;
 384                 }
 385                 return $title;
 386         }
 387
 388         /**
 389          * Make an array of titles from an array of IDs
 390          *
 391          * @param int[] $ids Array of IDs
 392          * @return Title[] Array of Titles
 393          */
 394         public static function newFromIDs( $ids ) {
 395                 if ( !count( $ids ) ) {
 396                         return array();
 397                 }
 398                 $dbr = wfGetDB( DB_SLAVE );
 399
 400                 $res = $dbr->select(
 401                         'page',
 402                         self::getSelectFields(),
 403                         array( 'page_id' => $ids ),
 404                         __METHOD__
 405                 );
 406
 407                 $titles = array();
 408                 foreach ( $res as $row ) {
 409                         $titles[] = Title::newFromRow( $row );
 410                 }
 411                 return $titles;
 412         }
 413
 414         /**
 415          * Make a Title object from a DB row
 416          *
 417          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 418          * @return Title Corresponding Title
 419          */
 420         public static function newFromRow( $row ) {
 421                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 422                 $t->loadFromRow( $row );
 423                 return $t;
 424         }
 425
 426         /**
 427          * Load Title object fields from a DB row.
 428          * If false is given, the title will be treated as non-existing.
 429          *
 430          * @param stdClass|bool $row Database row
 431          */
 432         public function loadFromRow( $row ) {
 433                 if ( $row ) { // page found
 434                         if ( isset( $row->page_id ) ) {
 435                                 $this->mArticleID = (int)$row->page_id;
 436                         }
 437                         if ( isset( $row->page_len ) ) {
 438                                 $this->mLength = (int)$row->page_len;
 439                         }
 440                         if ( isset( $row->page_is_redirect ) ) {
 441                                 $this->mRedirect = (bool)$row->page_is_redirect;
 442                         }
 443                         if ( isset( $row->page_latest ) ) {
 444                                 $this->mLatestID = (int)$row->page_latest;
 445                         }
 446                         if ( isset( $row->page_content_model ) ) {
 447                                 $this->mContentModel = strval( $row->page_content_model );
 448                         } else {
 449                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 450                         }
 451                         if ( isset( $row->page_lang ) ) {
 452                                 $this->mDbPageLanguage = (string)$row->page_lang;
 453                         }
 454                         if ( isset( $row->page_restrictions ) ) {
 455                                 $this->mOldRestrictions = $row->page_restrictions;
 456                         }
 457                 } else { // page not found
 458                         $this->mArticleID = 0;
 459                         $this->mLength = 0;
 460                         $this->mRedirect = false;
 461                         $this->mLatestID = 0;
 462                         $this->mContentModel = false; # initialized lazily in getContentModel()
 463                 }
 464         }
 465
 466         /**
 467          * Create a new Title from a namespace index and a DB key.
 468          * It's assumed that $ns and $title are *valid*, for instance when
 469          * they came directly from the database or a special page name.
 470          * For convenience, spaces are converted to underscores so that
 471          * eg user_text fields can be used directly.
 472          *
 473          * @param int $ns The namespace of the article
 474          * @param string $title The unprefixed database key form
 475          * @param string $fragment The link fragment (after the "#")
 476          * @param string $interwiki The interwiki prefix
 477          * @return Title The new object
 478          */
 479         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 480                 $t = new Title();
 481                 $t->mInterwiki = $interwiki;
 482                 $t->mFragment = $fragment;
 483                 $t->mNamespace = $ns = intval( $ns );
 484                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 485                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 486                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 487                 $t->mTextform = str_replace( '_', ' ', $title );
 488                 $t->mContentModel = false; # initialized lazily in getContentModel()
 489                 return $t;
 490         }
 491
 492         /**
 493          * Create a new Title from a namespace index and a DB key.
 494          * The parameters will be checked for validity, which is a bit slower
 495          * than makeTitle() but safer for user-provided data.
 496          *
 497          * @param int $ns The namespace of the article
 498          * @param string $title Database key form
 499          * @param string $fragment The link fragment (after the "#")
 500          * @param string $interwiki Interwiki prefix
 501          * @return Title The new object, or null on an error
 502          */
 503         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 504                 if ( !MWNamespace::exists( $ns ) ) {
 505                         return null;
 506                 }
 507
 508                 $t = new Title();
 509                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 510                 if ( $t->secureAndSplit() ) {
 511                         return $t;
 512                 } else {
 513                         return null;
 514                 }
 515         }
 516
 517         /**
 518          * Create a new Title for the Main Page
 519          *
 520          * @return Title The new object
 521          */
 522         public static function newMainPage() {
 523                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 524                 // Don't give fatal errors if the message is broken
 525                 if ( !$title ) {
 526                         $title = Title::newFromText( 'Main Page' );
 527                 }
 528                 return $title;
 529         }
 530
 531         /**
 532          * Extract a redirect destination from a string and return the
 533          * Title, or null if the text doesn't contain a valid redirect
 534          * This will only return the very next target, useful for
 535          * the redirect table and other checks that don't need full recursion
 536          *
 537          * @param string $text Text with possible redirect
 538          * @return Title The corresponding Title
 539          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 540          */
 541         public static function newFromRedirect( $text ) {
 542                 ContentHandler::deprecated( __METHOD__, '1.21' );
 543
 544                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 545                 return $content->getRedirectTarget();
 546         }
 547
 548         /**
 549          * Extract a redirect destination from a string and return the
 550          * Title, or null if the text doesn't contain a valid redirect
 551          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 552          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 553          *
 554          * @param string $text Text with possible redirect
 555          * @return Title
 556          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 557          */
 558         public static function newFromRedirectRecurse( $text ) {
 559                 ContentHandler::deprecated( __METHOD__, '1.21' );
 560
 561                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 562                 return $content->getUltimateRedirectTarget();
 563         }
 564
 565         /**
 566          * Extract a redirect destination from a string and return an
 567          * array of Titles, or null if the text doesn't contain a valid redirect
 568          * The last element in the array is the final destination after all redirects
 569          * have been resolved (up to $wgMaxRedirects times)
 570          *
 571          * @param string $text Text with possible redirect
 572          * @return Title[] Array of Titles, with the destination last
 573          * @deprecated since 1.21, use Content::getRedirectChain instead.
 574          */
 575         public static function newFromRedirectArray( $text ) {
 576                 ContentHandler::deprecated( __METHOD__, '1.21' );
 577
 578                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 579                 return $content->getRedirectChain();
 580         }
 581
 582         /**
 583          * Get the prefixed DB key associated with an ID
 584          *
 585          * @param int $id The page_id of the article
 586          * @return Title|null An object representing the article, or null if no such article was found
 587          */
 588         public static function nameOf( $id ) {
 589                 $dbr = wfGetDB( DB_SLAVE );
 590
 591                 $s = $dbr->selectRow(
 592                         'page',
 593                         array( 'page_namespace', 'page_title' ),
 594                         array( 'page_id' => $id ),
 595                         __METHOD__
 596                 );
 597                 if ( $s === false ) {
 598                         return null;
 599                 }
 600
 601                 $n = self::makeName( $s->page_namespace, $s->page_title );
 602                 return $n;
 603         }
 604
 605         /**
 606          * Get a regex character class describing the legal characters in a link
 607          *
 608          * @return string The list of characters, not delimited
 609          */
 610         public static function legalChars() {
 611                 global $wgLegalTitleChars;
 612                 return $wgLegalTitleChars;
 613         }
 614
 615         /**
 616          * Returns a simple regex that will match on characters and sequences invalid in titles.
 617          * Note that this doesn't pick up many things that could be wrong with titles, but that
 618          * replacing this regex with something valid will make many titles valid.
 619          *
 620          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 621          *
 622          * @return string Regex string
 623          */
 624         static function getTitleInvalidRegex() {
 625                 wfDeprecated( __METHOD__, '1.25' );
 626                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 627         }
 628
 629         /**
 630          * Utility method for converting a character sequence from bytes to Unicode.
 631          *
 632          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 633          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 634          *
 635          * @param string $byteClass
 636          * @return string
 637          */
 638         public static function convertByteClassToUnicodeClass( $byteClass ) {
 639                 $length = strlen( $byteClass );
 640                 // Input token queue
 641                 $x0 = $x1 = $x2 = '';
 642                 // Decoded queue
 643                 $d0 = $d1 = $d2 = '';
 644                 // Decoded integer codepoints
 645                 $ord0 = $ord1 = $ord2 = 0;
 646                 // Re-encoded queue
 647                 $r0 = $r1 = $r2 = '';
 648                 // Output
 649                 $out = '';
 650                 // Flags
 651                 $allowUnicode = false;
 652                 for ( $pos = 0; $pos < $length; $pos++ ) {
 653                         // Shift the queues down
 654                         $x2 = $x1;
 655                         $x1 = $x0;
 656                         $d2 = $d1;
 657                         $d1 = $d0;
 658                         $ord2 = $ord1;
 659                         $ord1 = $ord0;
 660                         $r2 = $r1;
 661                         $r1 = $r0;
 662                         // Load the current input token and decoded values
 663                         $inChar = $byteClass[$pos];
 664                         if ( $inChar == '\\' ) {
 665                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 666                                         $x0 = $inChar . $m[0];
 667                                         $d0 = chr( hexdec( $m[1] ) );
 668                                         $pos += strlen( $m[0] );
 669                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 670                                         $x0 = $inChar . $m[0];
 671                                         $d0 = chr( octdec( $m[0] ) );
 672                                         $pos += strlen( $m[0] );
 673                                 } elseif ( $pos + 1 >= $length ) {
 674                                         $x0 = $d0 = '\\';
 675                                 } else {
 676                                         $d0 = $byteClass[$pos + 1];
 677                                         $x0 = $inChar . $d0;
 678                                         $pos += 1;
 679                                 }
 680                         } else {
 681                                 $x0 = $d0 = $inChar;
 682                         }
 683                         $ord0 = ord( $d0 );
 684                         // Load the current re-encoded value
 685                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 686                                 $r0 = sprintf( '\x%02x', $ord0 );
 687                         } elseif ( $ord0 >= 0x80 ) {
 688                                 // Allow unicode if a single high-bit character appears
 689                                 $r0 = sprintf( '\x%02x', $ord0 );
 690                                 $allowUnicode = true;
 691                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 692                                 $r0 = '\\' . $d0;
 693                         } else {
 694                                 $r0 = $d0;
 695                         }
 696                         // Do the output
 697                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 698                                 // Range
 699                                 if ( $ord2 > $ord0 ) {
 700                                         // Empty range
 701                                 } elseif ( $ord0 >= 0x80 ) {
 702                                         // Unicode range
 703                                         $allowUnicode = true;
 704                                         if ( $ord2 < 0x80 ) {
 705                                                 // Keep the non-unicode section of the range
 706                                                 $out .= "$r2-\\x7F";
 707                                         }
 708                                 } else {
 709                                         // Normal range
 710                                         $out .= "$r2-$r0";
 711                                 }
 712                                 // Reset state to the initial value
 713                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 714                         } elseif ( $ord2 < 0x80 ) {
 715                                 // ASCII character
 716                                 $out .= $r2;
 717                         }
 718                 }
 719                 if ( $ord1 < 0x80 ) {
 720                         $out .= $r1;
 721                 }
 722                 if ( $ord0 < 0x80 ) {
 723                         $out .= $r0;
 724                 }
 725                 if ( $allowUnicode ) {
 726                         $out .= '\u0080-\uFFFF';
 727                 }
 728                 return $out;
 729         }
 730
 731         /**
 732          * Make a prefixed DB key from a DB key and a namespace index
 733          *
 734          * @param int $ns Numerical representation of the namespace
 735          * @param string $title The DB key form the title
 736          * @param string $fragment The link fragment (after the "#")
 737          * @param string $interwiki The interwiki prefix
 738          * @param bool $canoncialNamespace If true, use the canonical name for
 739          *   $ns instead of the localized version.
 740          * @return string The prefixed form of the title
 741          */
 742         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 743                 $canoncialNamespace = false
 744         ) {
 745                 global $wgContLang;
 746
 747                 if ( $canoncialNamespace ) {
 748                         $namespace = MWNamespace::getCanonicalName( $ns );
 749                 } else {
 750                         $namespace = $wgContLang->getNsText( $ns );
 751                 }
 752                 $name = $namespace == '' ? $title : "$namespace:$title";
 753                 if ( strval( $interwiki ) != '' ) {
 754                         $name = "$interwiki:$name";
 755                 }
 756                 if ( strval( $fragment ) != '' ) {
 757                         $name .= '#' . $fragment;
 758                 }
 759                 return $name;
 760         }
 761
 762         /**
 763          * Escape a text fragment, say from a link, for a URL
 764          *
 765          * @param string $fragment Containing a URL or link fragment (after the "#")
 766          * @return string Escaped string
 767          */
 768         static function escapeFragmentForURL( $fragment ) {
 769                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 770                 # fragments appear not to work in IE (at least up to 7) or in at least
 771                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 772                 # to care if they aren't encoded.
 773                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 774         }
 775
 776         /**
 777          * Callback for usort() to do title sorts by (namespace, title)
 778          *
 779          * @param Title $a
 780          * @param Title $b
 781          *
 782          * @return int Result of string comparison, or namespace comparison
 783          */
 784         public static function compare( $a, $b ) {
 785                 if ( $a->getNamespace() == $b->getNamespace() ) {
 786                         return strcmp( $a->getText(), $b->getText() );
 787                 } else {
 788                         return $a->getNamespace() - $b->getNamespace();
 789                 }
 790         }
 791
 792         /**
 793          * Determine whether the object refers to a page within
 794          * this project (either this wiki or a wiki with a local
 795          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 796          *
 797          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 798          */
 799         public function isLocal() {
 800                 if ( $this->isExternal() ) {
 801                         $iw = Interwiki::fetch( $this->mInterwiki );
 802                         if ( $iw ) {
 803                                 return $iw->isLocal();
 804                         }
 805                 }
 806                 return true;
 807         }
 808
 809         /**
 810          * Is this Title interwiki?
 811          *
 812          * @return bool
 813          */
 814         public function isExternal() {
 815                 return $this->mInterwiki !== '';
 816         }
 817
 818         /**
 819          * Get the interwiki prefix
 820          *
 821          * Use Title::isExternal to check if a interwiki is set
 822          *
 823          * @return string Interwiki prefix
 824          */
 825         public function getInterwiki() {
 826                 return $this->mInterwiki;
 827         }
 828
 829         /**
 830          * Was this a local interwiki link?
 831          *
 832          * @return bool
 833          */
 834         public function wasLocalInterwiki() {
 835                 return $this->mLocalInterwiki;
 836         }
 837
 838         /**
 839          * Determine whether the object refers to a page within
 840          * this project and is transcludable.
 841          *
 842          * @return bool True if this is transcludable
 843          */
 844         public function isTrans() {
 845                 if ( !$this->isExternal() ) {
 846                         return false;
 847                 }
 848
 849                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 850         }
 851
 852         /**
 853          * Returns the DB name of the distant wiki which owns the object.
 854          *
 855          * @return string The DB name
 856          */
 857         public function getTransWikiID() {
 858                 if ( !$this->isExternal() ) {
 859                         return false;
 860                 }
 861
 862                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 863         }
 864
 865         /**
 866          * Get a TitleValue object representing this Title.
 867          *
 868          * @note Not all valid Titles have a corresponding valid TitleValue
 869          * (e.g. TitleValues cannot represent page-local links that have a
 870          * fragment but no title text).
 871          *
 872          * @return TitleValue|null
 873          */
 874         public function getTitleValue() {
 875                 if ( $this->mTitleValue === null ) {
 876                         try {
 877                                 $this->mTitleValue = new TitleValue(
 878                                         $this->getNamespace(),
 879                                         $this->getDBkey(),
 880                                         $this->getFragment() );
 881                         } catch ( InvalidArgumentException $ex ) {
 882                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 883                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 884                         }
 885                 }
 886
 887                 return $this->mTitleValue;
 888         }
 889
 890         /**
 891          * Get the text form (spaces not underscores) of the main part
 892          *
 893          * @return string Main part of the title
 894          */
 895         public function getText() {
 896                 return $this->mTextform;
 897         }
 898
 899         /**
 900          * Get the URL-encoded form of the main part
 901          *
 902          * @return string Main part of the title, URL-encoded
 903          */
 904         public function getPartialURL() {
 905                 return $this->mUrlform;
 906         }
 907
 908         /**
 909          * Get the main part with underscores
 910          *
 911          * @return string Main part of the title, with underscores
 912          */
 913         public function getDBkey() {
 914                 return $this->mDbkeyform;
 915         }
 916
 917         /**
 918          * Get the DB key with the initial letter case as specified by the user
 919          *
 920          * @return string DB key
 921          */
 922         function getUserCaseDBKey() {
 923                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 924                         return $this->mUserCaseDBKey;
 925                 } else {
 926                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 927                         return $this->mDbkeyform;
 928                 }
 929         }
 930
 931         /**
 932          * Get the namespace index, i.e. one of the NS_xxxx constants.
 933          *
 934          * @return int Namespace index
 935          */
 936         public function getNamespace() {
 937                 return $this->mNamespace;
 938         }
 939
 940         /**
 941          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 942          *
 943          * @throws MWException
 944          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 945          * @return string Content model id
 946          */
 947         public function getContentModel( $flags = 0 ) {
 948                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 949                         $linkCache = LinkCache::singleton();
 950                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 951                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 952                 }
 953
 954                 if ( !$this->mContentModel ) {
 955                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 956                 }
 957
 958                 if ( !$this->mContentModel ) {
 959                         throw new MWException( 'Failed to determine content model!' );
 960                 }
 961
 962                 return $this->mContentModel;
 963         }
 964
 965         /**
 966          * Convenience method for checking a title's content model name
 967          *
 968          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 969          * @return bool True if $this->getContentModel() == $id
 970          */
 971         public function hasContentModel( $id ) {
 972                 return $this->getContentModel() == $id;
 973         }
 974
 975         /**
 976          * Get the namespace text
 977          *
 978          * @return string Namespace text
 979          */
 980         public function getNsText() {
 981                 if ( $this->isExternal() ) {
 982                         // This probably shouldn't even happen. ohh man, oh yuck.
 983                         // But for interwiki transclusion it sometimes does.
 984                         // Shit. Shit shit shit.
 985                         //
 986                         // Use the canonical namespaces if possible to try to
 987                         // resolve a foreign namespace.
 988                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 989                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 990                         }
 991                 }
 992
 993                 try {
 994                         $formatter = self::getTitleFormatter();
 995                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 996                 } catch ( InvalidArgumentException $ex ) {
 997                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 998                         return false;
 999                 }
1000         }
1001
1002         /**
1003          * Get the namespace text of the subject (rather than talk) page
1004          *
1005          * @return string Namespace text
1006          */
1007         public function getSubjectNsText() {
1008                 global $wgContLang;
1009                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1010         }
1011
1012         /**
1013          * Get the namespace text of the talk page
1014          *
1015          * @return string Namespace text
1016          */
1017         public function getTalkNsText() {
1018                 global $wgContLang;
1019                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1020         }
1021
1022         /**
1023          * Could this title have a corresponding talk page?
1024          *
1025          * @return bool
1026          */
1027         public function canTalk() {
1028                 return MWNamespace::canTalk( $this->mNamespace );
1029         }
1030
1031         /**
1032          * Is this in a namespace that allows actual pages?
1033          *
1034          * @return bool
1035          */
1036         public function canExist() {
1037                 return $this->mNamespace >= NS_MAIN;
1038         }
1039
1040         /**
1041          * Can this title be added to a user's watchlist?
1042          *
1043          * @return bool
1044          */
1045         public function isWatchable() {
1046                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1047         }
1048
1049         /**
1050          * Returns true if this is a special page.
1051          *
1052          * @return bool
1053          */
1054         public function isSpecialPage() {
1055                 return $this->getNamespace() == NS_SPECIAL;
1056         }
1057
1058         /**
1059          * Returns true if this title resolves to the named special page
1060          *
1061          * @param string $name The special page name
1062          * @return bool
1063          */
1064         public function isSpecial( $name ) {
1065                 if ( $this->isSpecialPage() ) {
1066                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1067                         if ( $name == $thisName ) {
1068                                 return true;
1069                         }
1070                 }
1071                 return false;
1072         }
1073
1074         /**
1075          * If the Title refers to a special page alias which is not the local default, resolve
1076          * the alias, and localise the name as necessary.  Otherwise, return $this
1077          *
1078          * @return Title
1079          */
1080         public function fixSpecialName() {
1081                 if ( $this->isSpecialPage() ) {
1082                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1083                         if ( $canonicalName ) {
1084                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1085                                 if ( $localName != $this->mDbkeyform ) {
1086                                         return Title::makeTitle( NS_SPECIAL, $localName );
1087                                 }
1088                         }
1089                 }
1090                 return $this;
1091         }
1092
1093         /**
1094          * Returns true if the title is inside the specified namespace.
1095          *
1096          * Please make use of this instead of comparing to getNamespace()
1097          * This function is much more resistant to changes we may make
1098          * to namespaces than code that makes direct comparisons.
1099          * @param int $ns The namespace
1100          * @return bool
1101          * @since 1.19
1102          */
1103         public function inNamespace( $ns ) {
1104                 return MWNamespace::equals( $this->getNamespace(), $ns );
1105         }
1106
1107         /**
1108          * Returns true if the title is inside one of the specified namespaces.
1109          *
1110          * @param int $namespaces,... The namespaces to check for
1111          * @return bool
1112          * @since 1.19
1113          */
1114         public function inNamespaces( /* ... */ ) {
1115                 $namespaces = func_get_args();
1116                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1117                         $namespaces = $namespaces[0];
1118                 }
1119
1120                 foreach ( $namespaces as $ns ) {
1121                         if ( $this->inNamespace( $ns ) ) {
1122                                 return true;
1123                         }
1124                 }
1125
1126                 return false;
1127         }
1128
1129         /**
1130          * Returns true if the title has the same subject namespace as the
1131          * namespace specified.
1132          * For example this method will take NS_USER and return true if namespace
1133          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1134          * as their subject namespace.
1135          *
1136          * This is MUCH simpler than individually testing for equivalence
1137          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1138          * @since 1.19
1139          * @param int $ns
1140          * @return bool
1141          */
1142         public function hasSubjectNamespace( $ns ) {
1143                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1144         }
1145
1146         /**
1147          * Is this Title in a namespace which contains content?
1148          * In other words, is this a content page, for the purposes of calculating
1149          * statistics, etc?
1150          *
1151          * @return bool
1152          */
1153         public function isContentPage() {
1154                 return MWNamespace::isContent( $this->getNamespace() );
1155         }
1156
1157         /**
1158          * Would anybody with sufficient privileges be able to move this page?
1159          * Some pages just aren't movable.
1160          *
1161          * @return bool
1162          */
1163         public function isMovable() {
1164                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1165                         // Interwiki title or immovable namespace. Hooks don't get to override here
1166                         return false;
1167                 }
1168
1169                 $result = true;
1170                 Hooks::run( 'TitleIsMovable', array( $this, &$result ) );
1171                 return $result;
1172         }
1173
1174         /**
1175          * Is this the mainpage?
1176          * @note Title::newFromText seems to be sufficiently optimized by the title
1177          * cache that we don't need to over-optimize by doing direct comparisons and
1178          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1179          * ends up reporting something differently than $title->isMainPage();
1180          *
1181          * @since 1.18
1182          * @return bool
1183          */
1184         public function isMainPage() {
1185                 return $this->equals( Title::newMainPage() );
1186         }
1187
1188         /**
1189          * Is this a subpage?
1190          *
1191          * @return bool
1192          */
1193         public function isSubpage() {
1194                 return MWNamespace::hasSubpages( $this->mNamespace )
1195                         ? strpos( $this->getText(), '/' ) !== false
1196                         : false;
1197         }
1198
1199         /**
1200          * Is this a conversion table for the LanguageConverter?
1201          *
1202          * @return bool
1203          */
1204         public function isConversionTable() {
1205                 // @todo ConversionTable should become a separate content model.
1206
1207                 return $this->getNamespace() == NS_MEDIAWIKI &&
1208                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1209         }
1210
1211         /**
1212          * Does that page contain wikitext, or it is JS, CSS or whatever?
1213          *
1214          * @return bool
1215          */
1216         public function isWikitextPage() {
1217                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1218         }
1219
1220         /**
1221          * Could this page contain custom CSS or JavaScript for the global UI.
1222          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1223          * or CONTENT_MODEL_JAVASCRIPT.
1224          *
1225          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1226          * for that!
1227          *
1228          * Note that this method should not return true for pages that contain and
1229          * show "inactive" CSS or JS.
1230          *
1231          * @return bool
1232          */
1233         public function isCssOrJsPage() {
1234                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1235                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1236                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1237
1238                 # @note This hook is also called in ContentHandler::getDefaultModel.
1239                 #   It's called here again to make sure hook functions can force this
1240                 #   method to return true even outside the MediaWiki namespace.
1241
1242                 Hooks::run( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ), '1.25' );
1243
1244                 return $isCssOrJsPage;
1245         }
1246
1247         /**
1248          * Is this a .css or .js subpage of a user page?
1249          * @return bool
1250          */
1251         public function isCssJsSubpage() {
1252                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1253                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1254                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1255         }
1256
1257         /**
1258          * Trim down a .css or .js subpage title to get the corresponding skin name
1259          *
1260          * @return string Containing skin name from .css or .js subpage title
1261          */
1262         public function getSkinFromCssJsSubpage() {
1263                 $subpage = explode( '/', $this->mTextform );
1264                 $subpage = $subpage[count( $subpage ) - 1];
1265                 $lastdot = strrpos( $subpage, '.' );
1266                 if ( $lastdot === false ) {
1267                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1268                 }
1269                 return substr( $subpage, 0, $lastdot );
1270         }
1271
1272         /**
1273          * Is this a .css subpage of a user page?
1274          *
1275          * @return bool
1276          */
1277         public function isCssSubpage() {
1278                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1279                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1280         }
1281
1282         /**
1283          * Is this a .js subpage of a user page?
1284          *
1285          * @return bool
1286          */
1287         public function isJsSubpage() {
1288                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1289                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1290         }
1291
1292         /**
1293          * Is this a talk page of some sort?
1294          *
1295          * @return bool
1296          */
1297         public function isTalkPage() {
1298                 return MWNamespace::isTalk( $this->getNamespace() );
1299         }
1300
1301         /**
1302          * Get a Title object associated with the talk page of this article
1303          *
1304          * @return Title The object for the talk page
1305          */
1306         public function getTalkPage() {
1307                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1308         }
1309
1310         /**
1311          * Get a title object associated with the subject page of this
1312          * talk page
1313          *
1314          * @return Title The object for the subject page
1315          */
1316         public function getSubjectPage() {
1317                 // Is this the same title?
1318                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1319                 if ( $this->getNamespace() == $subjectNS ) {
1320                         return $this;
1321                 }
1322                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1323         }
1324
1325         /**
1326          * Get the other title for this page, if this is a subject page
1327          * get the talk page, if it is a subject page get the talk page
1328          *
1329          * @since 1.25
1330          * @throws MWException
1331          * @return Title
1332          */
1333         public function getOtherPage() {
1334                 if ( $this->isSpecialPage() ) {
1335                         throw new MWException( 'Special pages cannot have other pages' );
1336                 }
1337                 if ( $this->isTalkPage() ) {
1338                         return $this->getSubjectPage();
1339                 } else {
1340                         return $this->getTalkPage();
1341                 }
1342         }
1343
1344         /**
1345          * Get the default namespace index, for when there is no namespace
1346          *
1347          * @return int Default namespace index
1348          */
1349         public function getDefaultNamespace() {
1350                 return $this->mDefaultNamespace;
1351         }
1352
1353         /**
1354          * Get the Title fragment (i.e.\ the bit after the #) in text form
1355          *
1356          * Use Title::hasFragment to check for a fragment
1357          *
1358          * @return string Title fragment
1359          */
1360         public function getFragment() {
1361                 return $this->mFragment;
1362         }
1363
1364         /**
1365          * Check if a Title fragment is set
1366          *
1367          * @return bool
1368          * @since 1.23
1369          */
1370         public function hasFragment() {
1371                 return $this->mFragment !== '';
1372         }
1373
1374         /**
1375          * Get the fragment in URL form, including the "#" character if there is one
1376          * @return string Fragment in URL form
1377          */
1378         public function getFragmentForURL() {
1379                 if ( !$this->hasFragment() ) {
1380                         return '';
1381                 } else {
1382                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1383                 }
1384         }
1385
1386         /**
1387          * Set the fragment for this title. Removes the first character from the
1388          * specified fragment before setting, so it assumes you're passing it with
1389          * an initial "#".
1390          *
1391          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1392          * Still in active use privately.
1393          *
1394          * @param string $fragment Text
1395          */
1396         public function setFragment( $fragment ) {
1397                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1398         }
1399
1400         /**
1401          * Prefix some arbitrary text with the namespace or interwiki prefix
1402          * of this object
1403          *
1404          * @param string $name The text
1405          * @return string The prefixed text
1406          */
1407         private function prefix( $name ) {
1408                 $p = '';
1409                 if ( $this->isExternal() ) {
1410                         $p = $this->mInterwiki . ':';
1411                 }
1412
1413                 if ( 0 != $this->mNamespace ) {
1414                         $p .= $this->getNsText() . ':';
1415                 }
1416                 return $p . $name;
1417         }
1418
1419         /**
1420          * Get the prefixed database key form
1421          *
1422          * @return string The prefixed title, with underscores and
1423          *  any interwiki and namespace prefixes
1424          */
1425         public function getPrefixedDBkey() {
1426                 $s = $this->prefix( $this->mDbkeyform );
1427                 $s = str_replace( ' ', '_', $s );
1428                 return $s;
1429         }
1430
1431         /**
1432          * Get the prefixed title with spaces.
1433          * This is the form usually used for display
1434          *
1435          * @return string The prefixed title, with spaces
1436          */
1437         public function getPrefixedText() {
1438                 if ( $this->mPrefixedText === null ) {
1439                         $s = $this->prefix( $this->mTextform );
1440                         $s = str_replace( '_', ' ', $s );
1441                         $this->mPrefixedText = $s;
1442                 }
1443                 return $this->mPrefixedText;
1444         }
1445
1446         /**
1447          * Return a string representation of this title
1448          *
1449          * @return string Representation of this title
1450          */
1451         public function __toString() {
1452                 return $this->getPrefixedText();
1453         }
1454
1455         /**
1456          * Get the prefixed title with spaces, plus any fragment
1457          * (part beginning with '#')
1458          *
1459          * @return string The prefixed title, with spaces and the fragment, including '#'
1460          */
1461         public function getFullText() {
1462                 $text = $this->getPrefixedText();
1463                 if ( $this->hasFragment() ) {
1464                         $text .= '#' . $this->getFragment();
1465                 }
1466                 return $text;
1467         }
1468
1469         /**
1470          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1471          *
1472          * @par Example:
1473          * @code
1474          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1475          * # returns: 'Foo'
1476          * @endcode
1477          *
1478          * @return string Root name
1479          * @since 1.20
1480          */
1481         public function getRootText() {
1482                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1483                         return $this->getText();
1484                 }
1485
1486                 return strtok( $this->getText(), '/' );
1487         }
1488
1489         /**
1490          * Get the root page name title, i.e. the leftmost part before any slashes
1491          *
1492          * @par Example:
1493          * @code
1494          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1495          * # returns: Title{User:Foo}
1496          * @endcode
1497          *
1498          * @return Title Root title
1499          * @since 1.20
1500          */
1501         public function getRootTitle() {
1502                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1503         }
1504
1505         /**
1506          * Get the base page name without a namespace, i.e. the part before the subpage name
1507          *
1508          * @par Example:
1509          * @code
1510          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1511          * # returns: 'Foo/Bar'
1512          * @endcode
1513          *
1514          * @return string Base name
1515          */
1516         public function getBaseText() {
1517                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1518                         return $this->getText();
1519                 }
1520
1521                 $parts = explode( '/', $this->getText() );
1522                 # Don't discard the real title if there's no subpage involved
1523                 if ( count( $parts ) > 1 ) {
1524                         unset( $parts[count( $parts ) - 1] );
1525                 }
1526                 return implode( '/', $parts );
1527         }
1528
1529         /**
1530          * Get the base page name title, i.e. the part before the subpage name
1531          *
1532          * @par Example:
1533          * @code
1534          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1535          * # returns: Title{User:Foo/Bar}
1536          * @endcode
1537          *
1538          * @return Title Base title
1539          * @since 1.20
1540          */
1541         public function getBaseTitle() {
1542                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1543         }
1544
1545         /**
1546          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1547          *
1548          * @par Example:
1549          * @code
1550          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1551          * # returns: "Baz"
1552          * @endcode
1553          *
1554          * @return string Subpage name
1555          */
1556         public function getSubpageText() {
1557                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1558                         return $this->mTextform;
1559                 }
1560                 $parts = explode( '/', $this->mTextform );
1561                 return $parts[count( $parts ) - 1];
1562         }
1563
1564         /**
1565          * Get the title for a subpage of the current page
1566          *
1567          * @par Example:
1568          * @code
1569          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1570          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1571          * @endcode
1572          *
1573          * @param string $text The subpage name to add to the title
1574          * @return Title Subpage title
1575          * @since 1.20
1576          */
1577         public function getSubpage( $text ) {
1578                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1579         }
1580
1581         /**
1582          * Get a URL-encoded form of the subpage text
1583          *
1584          * @return string URL-encoded subpage name
1585          */
1586         public function getSubpageUrlForm() {
1587                 $text = $this->getSubpageText();
1588                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1589                 return $text;
1590         }
1591
1592         /**
1593          * Get a URL-encoded title (not an actual URL) including interwiki
1594          *
1595          * @return string The URL-encoded form
1596          */
1597         public function getPrefixedURL() {
1598                 $s = $this->prefix( $this->mDbkeyform );
1599                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1600                 return $s;
1601         }
1602
1603         /**
1604          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1605          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1606          * second argument named variant. This was deprecated in favor
1607          * of passing an array of option with a "variant" key
1608          * Once $query2 is removed for good, this helper can be dropped
1609          * and the wfArrayToCgi moved to getLocalURL();
1610          *
1611          * @since 1.19 (r105919)
1612          * @param array|string $query
1613          * @param bool $query2
1614          * @return string
1615          */
1616         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1617                 if ( $query2 !== false ) {
1618                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1619                                 "method called with a second parameter is deprecated. Add your " .
1620                                 "parameter to an array passed as the first parameter.", "1.19" );
1621                 }
1622                 if ( is_array( $query ) ) {
1623                         $query = wfArrayToCgi( $query );
1624                 }
1625                 if ( $query2 ) {
1626                         if ( is_string( $query2 ) ) {
1627                                 // $query2 is a string, we will consider this to be
1628                                 // a deprecated $variant argument and add it to the query
1629                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1630                         } else {
1631                                 $query2 = wfArrayToCgi( $query2 );
1632                         }
1633                         // If we have $query content add a & to it first
1634                         if ( $query ) {
1635                                 $query .= '&';
1636                         }
1637                         // Now append the queries together
1638                         $query .= $query2;
1639                 }
1640                 return $query;
1641         }
1642
1643         /**
1644          * Get a real URL referring to this title, with interwiki link and
1645          * fragment
1646          *
1647          * @see self::getLocalURL for the arguments.
1648          * @see wfExpandUrl
1649          * @param array|string $query
1650          * @param bool $query2
1651          * @param string $proto Protocol type to use in URL
1652          * @return string The URL
1653          */
1654         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1655                 $query = self::fixUrlQueryArgs( $query, $query2 );
1656
1657                 # Hand off all the decisions on urls to getLocalURL
1658                 $url = $this->getLocalURL( $query );
1659
1660                 # Expand the url to make it a full url. Note that getLocalURL has the
1661                 # potential to output full urls for a variety of reasons, so we use
1662                 # wfExpandUrl instead of simply prepending $wgServer
1663                 $url = wfExpandUrl( $url, $proto );
1664
1665                 # Finally, add the fragment.
1666                 $url .= $this->getFragmentForURL();
1667
1668                 Hooks::run( 'GetFullURL', array( &$this, &$url, $query ) );
1669                 return $url;
1670         }
1671
1672         /**
1673          * Get a URL with no fragment or server name (relative URL) from a Title object.
1674          * If this page is generated with action=render, however,
1675          * $wgServer is prepended to make an absolute URL.
1676          *
1677          * @see self::getFullURL to always get an absolute URL.
1678          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1679          *  valid to link, locally, to the current Title.
1680          * @see self::newFromText to produce a Title object.
1681          *
1682          * @param string|array $query An optional query string,
1683          *   not used for interwiki links. Can be specified as an associative array as well,
1684          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1685          *   Some query patterns will trigger various shorturl path replacements.
1686          * @param array $query2 An optional secondary query array. This one MUST
1687          *   be an array. If a string is passed it will be interpreted as a deprecated
1688          *   variant argument and urlencoded into a variant= argument.
1689          *   This second query argument will be added to the $query
1690          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1691          *   pair in the first parameter array instead.
1692          *
1693          * @return string String of the URL.
1694          */
1695         public function getLocalURL( $query = '', $query2 = false ) {
1696                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1697
1698                 $query = self::fixUrlQueryArgs( $query, $query2 );
1699
1700                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1701                 if ( $interwiki ) {
1702                         $namespace = $this->getNsText();
1703                         if ( $namespace != '' ) {
1704                                 # Can this actually happen? Interwikis shouldn't be parsed.
1705                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1706                                 $namespace .= ':';
1707                         }
1708                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1709                         $url = wfAppendQuery( $url, $query );
1710                 } else {
1711                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1712                         if ( $query == '' ) {
1713                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1714                                 Hooks::run( 'GetLocalURL::Article', array( &$this, &$url ) );
1715                         } else {
1716                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1717                                 $url = false;
1718                                 $matches = array();
1719
1720                                 if ( !empty( $wgActionPaths )
1721                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1722                                 ) {
1723                                         $action = urldecode( $matches[2] );
1724                                         if ( isset( $wgActionPaths[$action] ) ) {
1725                                                 $query = $matches[1];
1726                                                 if ( isset( $matches[4] ) ) {
1727                                                         $query .= $matches[4];
1728                                                 }
1729                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1730                                                 if ( $query != '' ) {
1731                                                         $url = wfAppendQuery( $url, $query );
1732                                                 }
1733                                         }
1734                                 }
1735
1736                                 if ( $url === false
1737                                         && $wgVariantArticlePath
1738                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1739                                         && $this->getPageLanguage()->hasVariants()
1740                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1741                                 ) {
1742                                         $variant = urldecode( $matches[1] );
1743                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1744                                                 // Only do the variant replacement if the given variant is a valid
1745                                                 // variant for the page's language.
1746                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1747                                                 $url = str_replace( '$1', $dbkey, $url );
1748                                         }
1749                                 }
1750
1751                                 if ( $url === false ) {
1752                                         if ( $query == '-' ) {
1753                                                 $query = '';
1754                                         }
1755                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1756                                 }
1757                         }
1758
1759                         Hooks::run( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1760
1761                         // @todo FIXME: This causes breakage in various places when we
1762                         // actually expected a local URL and end up with dupe prefixes.
1763                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1764                                 $url = $wgServer . $url;
1765                         }
1766                 }
1767                 Hooks::run( 'GetLocalURL', array( &$this, &$url, $query ) );
1768                 return $url;
1769         }
1770
1771         /**
1772          * Get a URL that's the simplest URL that will be valid to link, locally,
1773          * to the current Title.  It includes the fragment, but does not include
1774          * the server unless action=render is used (or the link is external).  If
1775          * there's a fragment but the prefixed text is empty, we just return a link
1776          * to the fragment.
1777          *
1778          * The result obviously should not be URL-escaped, but does need to be
1779          * HTML-escaped if it's being output in HTML.
1780          *
1781          * @param array $query
1782          * @param bool $query2
1783          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1784          * @see self::getLocalURL for the arguments.
1785          * @return string The URL
1786          */
1787         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1788                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1789                         $ret = $this->getFullURL( $query, $query2, $proto );
1790                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1791                         $ret = $this->getFragmentForURL();
1792                 } else {
1793                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1794                 }
1795                 return $ret;
1796         }
1797
1798         /**
1799          * Get the URL form for an internal link.
1800          * - Used in various Squid-related code, in case we have a different
1801          * internal hostname for the server from the exposed one.
1802          *
1803          * This uses $wgInternalServer to qualify the path, or $wgServer
1804          * if $wgInternalServer is not set. If the server variable used is
1805          * protocol-relative, the URL will be expanded to http://
1806          *
1807          * @see self::getLocalURL for the arguments.
1808          * @return string The URL
1809          */
1810         public function getInternalURL( $query = '', $query2 = false ) {
1811                 global $wgInternalServer, $wgServer;
1812                 $query = self::fixUrlQueryArgs( $query, $query2 );
1813                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1814                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1815                 Hooks::run( 'GetInternalURL', array( &$this, &$url, $query ) );
1816                 return $url;
1817         }
1818
1819         /**
1820          * Get the URL for a canonical link, for use in things like IRC and
1821          * e-mail notifications. Uses $wgCanonicalServer and the
1822          * GetCanonicalURL hook.
1823          *
1824          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1825          *
1826          * @see self::getLocalURL for the arguments.
1827          * @return string The URL
1828          * @since 1.18
1829          */
1830         public function getCanonicalURL( $query = '', $query2 = false ) {
1831                 $query = self::fixUrlQueryArgs( $query, $query2 );
1832                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1833                 Hooks::run( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1834                 return $url;
1835         }
1836
1837         /**
1838          * Get the edit URL for this Title
1839          *
1840          * @return string The URL, or a null string if this is an interwiki link
1841          */
1842         public function getEditURL() {
1843                 if ( $this->isExternal() ) {
1844                         return '';
1845                 }
1846                 $s = $this->getLocalURL( 'action=edit' );
1847
1848                 return $s;
1849         }
1850
1851         /**
1852          * Is $wgUser watching this page?
1853          *
1854          * @deprecated since 1.20; use User::isWatched() instead.
1855          * @return bool
1856          */
1857         public function userIsWatching() {
1858                 global $wgUser;
1859
1860                 if ( is_null( $this->mWatched ) ) {
1861                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1862                                 $this->mWatched = false;
1863                         } else {
1864                                 $this->mWatched = $wgUser->isWatched( $this );
1865                         }
1866                 }
1867                 return $this->mWatched;
1868         }
1869
1870         /**
1871          * Can $user perform $action on this page?
1872          * This skips potentially expensive cascading permission checks
1873          * as well as avoids expensive error formatting
1874          *
1875          * Suitable for use for nonessential UI controls in common cases, but
1876          * _not_ for functional access control.
1877          *
1878          * May provide false positives, but should never provide a false negative.
1879          *
1880          * @param string $action Action that permission needs to be checked for
1881          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1882          * @return bool
1883          */
1884         public function quickUserCan( $action, $user = null ) {
1885                 return $this->userCan( $action, $user, false );
1886         }
1887
1888         /**
1889          * Can $user perform $action on this page?
1890          *
1891          * @param string $action Action that permission needs to be checked for
1892          * @param User $user User to check (since 1.19); $wgUser will be used if not
1893          *   provided.
1894          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1895          * @return bool
1896          */
1897         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1898                 if ( !$user instanceof User ) {
1899                         global $wgUser;
1900                         $user = $wgUser;
1901                 }
1902
1903                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1904         }
1905
1906         /**
1907          * Can $user perform $action on this page?
1908          *
1909          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1910          *
1911          * @param string $action Action that permission needs to be checked for
1912          * @param User $user User to check
1913          * @param string $rigor One of (quick,full,secure)
1914          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
1915          *   - full   : does cheap and expensive checks possibly from a slave
1916          *   - secure : does cheap and expensive checks, using the master as needed
1917          * @param bool $short Set this to true to stop after the first permission error.
1918          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1919          *   whose corresponding errors may be ignored.
1920          * @return array Array of arguments to wfMessage to explain permissions problems.
1921          */
1922         public function getUserPermissionsErrors(
1923                 $action, $user, $rigor = 'secure', $ignoreErrors = array()
1924         ) {
1925                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1926
1927                 // Remove the errors being ignored.
1928                 foreach ( $errors as $index => $error ) {
1929                         $error_key = is_array( $error ) ? $error[0] : $error;
1930
1931                         if ( in_array( $error_key, $ignoreErrors ) ) {
1932                                 unset( $errors[$index] );
1933                         }
1934                 }
1935
1936                 return $errors;
1937         }
1938
1939         /**
1940          * Permissions checks that fail most often, and which are easiest to test.
1941          *
1942          * @param string $action The action to check
1943          * @param User $user User to check
1944          * @param array $errors List of current errors
1945          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1946          * @param bool $short Short circuit on first error
1947          *
1948          * @return array List of errors
1949          */
1950         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1951                 if ( !Hooks::run( 'TitleQuickPermissions',
1952                         array( $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ) )
1953                 ) {
1954                         return $errors;
1955                 }
1956
1957                 if ( $action == 'create' ) {
1958                         if (
1959                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1960                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1961                         ) {
1962                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1963                         }
1964                 } elseif ( $action == 'move' ) {
1965                         if ( !$user->isAllowed( 'move-rootuserpages' )
1966                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1967                                 // Show user page-specific message only if the user can move other pages
1968                                 $errors[] = array( 'cant-move-user-page' );
1969                         }
1970
1971                         // Check if user is allowed to move files if it's a file
1972                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1973                                 $errors[] = array( 'movenotallowedfile' );
1974                         }
1975
1976                         // Check if user is allowed to move category pages if it's a category page
1977                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1978                                 $errors[] = array( 'cant-move-category-page' );
1979                         }
1980
1981                         if ( !$user->isAllowed( 'move' ) ) {
1982                                 // User can't move anything
1983                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1984                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1985                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1986                                         // custom message if logged-in users without any special rights can move
1987                                         $errors[] = array( 'movenologintext' );
1988                                 } else {
1989                                         $errors[] = array( 'movenotallowed' );
1990                                 }
1991                         }
1992                 } elseif ( $action == 'move-target' ) {
1993                         if ( !$user->isAllowed( 'move' ) ) {
1994                                 // User can't move anything
1995                                 $errors[] = array( 'movenotallowed' );
1996                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1997                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1998                                 // Show user page-specific message only if the user can move other pages
1999                                 $errors[] = array( 'cant-move-to-user-page' );
2000                         } elseif ( !$user->isAllowed( 'move-categorypages' )
2001                                         && $this->mNamespace == NS_CATEGORY ) {
2002                                 // Show category page-specific message only if the user can move other pages
2003                                 $errors[] = array( 'cant-move-to-category-page' );
2004                         }
2005                 } elseif ( !$user->isAllowed( $action ) ) {
2006                         $errors[] = $this->missingPermissionError( $action, $short );
2007                 }
2008
2009                 return $errors;
2010         }
2011
2012         /**
2013          * Add the resulting error code to the errors array
2014          *
2015          * @param array $errors List of current errors
2016          * @param array $result Result of errors
2017          *
2018          * @return array List of errors
2019          */
2020         private function resultToError( $errors, $result ) {
2021                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2022                         // A single array representing an error
2023                         $errors[] = $result;
2024                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2025                         // A nested array representing multiple errors
2026                         $errors = array_merge( $errors, $result );
2027                 } elseif ( $result !== '' && is_string( $result ) ) {
2028                         // A string representing a message-id
2029                         $errors[] = array( $result );
2030                 } elseif ( $result === false ) {
2031                         // a generic "We don't want them to do that"
2032                         $errors[] = array( 'badaccess-group0' );
2033                 }
2034                 return $errors;
2035         }
2036
2037         /**
2038          * Check various permission hooks
2039          *
2040          * @param string $action The action to check
2041          * @param User $user User to check
2042          * @param array $errors List of current errors
2043          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2044          * @param bool $short Short circuit on first error
2045          *
2046          * @return array List of errors
2047          */
2048         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2049                 // Use getUserPermissionsErrors instead
2050                 $result = '';
2051                 if ( !Hooks::run( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2052                         return $result ? array() : array( array( 'badaccess-group0' ) );
2053                 }
2054                 // Check getUserPermissionsErrors hook
2055                 if ( !Hooks::run( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2056                         $errors = $this->resultToError( $errors, $result );
2057                 }
2058                 // Check getUserPermissionsErrorsExpensive hook
2059                 if (
2060                         $rigor !== 'quick'
2061                         && !( $short && count( $errors ) > 0 )
2062                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2063                 ) {
2064                         $errors = $this->resultToError( $errors, $result );
2065                 }
2066
2067                 return $errors;
2068         }
2069
2070         /**
2071          * Check permissions on special pages & namespaces
2072          *
2073          * @param string $action The action to check
2074          * @param User $user User to check
2075          * @param array $errors List of current errors
2076          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2077          * @param bool $short Short circuit on first error
2078          *
2079          * @return array List of errors
2080          */
2081         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2082                 # Only 'createaccount' can be performed on special pages,
2083                 # which don't actually exist in the DB.
2084                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2085                         $errors[] = array( 'ns-specialprotected' );
2086                 }
2087
2088                 # Check $wgNamespaceProtection for restricted namespaces
2089                 if ( $this->isNamespaceProtected( $user ) ) {
2090                         $ns = $this->mNamespace == NS_MAIN ?
2091                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2092                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2093                                 array( 'protectedinterface', $action ) : array( 'namespaceprotected', $ns, $action );
2094                 }
2095
2096                 return $errors;
2097         }
2098
2099         /**
2100          * Check CSS/JS sub-page permissions
2101          *
2102          * @param string $action The action to check
2103          * @param User $user User to check
2104          * @param array $errors List of current errors
2105          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2106          * @param bool $short Short circuit on first error
2107          *
2108          * @return array List of errors
2109          */
2110         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2111                 # Protect css/js subpages of user pages
2112                 # XXX: this might be better using restrictions
2113                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2114                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2115                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2116                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2117                                         $errors[] = array( 'mycustomcssprotected', $action );
2118                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2119                                         $errors[] = array( 'mycustomjsprotected', $action );
2120                                 }
2121                         } else {
2122                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2123                                         $errors[] = array( 'customcssprotected', $action );
2124                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2125                                         $errors[] = array( 'customjsprotected', $action );
2126                                 }
2127                         }
2128                 }
2129
2130                 return $errors;
2131         }
2132
2133         /**
2134          * Check against page_restrictions table requirements on this
2135          * page. The user must possess all required rights for this
2136          * action.
2137          *
2138          * @param string $action The action to check
2139          * @param User $user User to check
2140          * @param array $errors List of current errors
2141          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2142          * @param bool $short Short circuit on first error
2143          *
2144          * @return array List of errors
2145          */
2146         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2147                 foreach ( $this->getRestrictions( $action ) as $right ) {
2148                         // Backwards compatibility, rewrite sysop -> editprotected
2149                         if ( $right == 'sysop' ) {
2150                                 $right = 'editprotected';
2151                         }
2152                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2153                         if ( $right == 'autoconfirmed' ) {
2154                                 $right = 'editsemiprotected';
2155                         }
2156                         if ( $right == '' ) {
2157                                 continue;
2158                         }
2159                         if ( !$user->isAllowed( $right ) ) {
2160                                 $errors[] = array( 'protectedpagetext', $right, $action );
2161                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2162                                 $errors[] = array( 'protectedpagetext', 'protect', $action );
2163                         }
2164                 }
2165
2166                 return $errors;
2167         }
2168
2169         /**
2170          * Check restrictions on cascading pages.
2171          *
2172          * @param string $action The action to check
2173          * @param User $user User to check
2174          * @param array $errors List of current errors
2175          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2176          * @param bool $short Short circuit on first error
2177          *
2178          * @return array List of errors
2179          */
2180         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2181                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2182                         # We /could/ use the protection level on the source page, but it's
2183                         # fairly ugly as we have to establish a precedence hierarchy for pages
2184                         # included by multiple cascade-protected pages. So just restrict
2185                         # it to people with 'protect' permission, as they could remove the
2186                         # protection anyway.
2187                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2188                         # Cascading protection depends on more than this page...
2189                         # Several cascading protected pages may include this page...
2190                         # Check each cascading level
2191                         # This is only for protection restrictions, not for all actions
2192                         if ( isset( $restrictions[$action] ) ) {
2193                                 foreach ( $restrictions[$action] as $right ) {
2194                                         // Backwards compatibility, rewrite sysop -> editprotected
2195                                         if ( $right == 'sysop' ) {
2196                                                 $right = 'editprotected';
2197                                         }
2198                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2199                                         if ( $right == 'autoconfirmed' ) {
2200                                                 $right = 'editsemiprotected';
2201                                         }
2202                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2203                                                 $pages = '';
2204                                                 foreach ( $cascadingSources as $page ) {
2205                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2206                                                 }
2207                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages, $action );
2208                                         }
2209                                 }
2210                         }
2211                 }
2212
2213                 return $errors;
2214         }
2215
2216         /**
2217          * Check action permissions not already checked in checkQuickPermissions
2218          *
2219          * @param string $action The action to check
2220          * @param User $user User to check
2221          * @param array $errors List of current errors
2222          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2223          * @param bool $short Short circuit on first error
2224          *
2225          * @return array List of errors
2226          */
2227         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2228                 global $wgDeleteRevisionsLimit, $wgLang;
2229
2230                 if ( $action == 'protect' ) {
2231                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2232                                 // If they can't edit, they shouldn't protect.
2233                                 $errors[] = array( 'protect-cantedit' );
2234                         }
2235                 } elseif ( $action == 'create' ) {
2236                         $title_protection = $this->getTitleProtection();
2237                         if ( $title_protection ) {
2238                                 if ( $title_protection['permission'] == ''
2239                                         || !$user->isAllowed( $title_protection['permission'] )
2240                                 ) {
2241                                         $errors[] = array(
2242                                                 'titleprotected',
2243                                                 User::whoIs( $title_protection['user'] ),
2244                                                 $title_protection['reason']
2245                                         );
2246                                 }
2247                         }
2248                 } elseif ( $action == 'move' ) {
2249                         // Check for immobile pages
2250                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2251                                 // Specific message for this case
2252                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2253                         } elseif ( !$this->isMovable() ) {
2254                                 // Less specific message for rarer cases
2255                                 $errors[] = array( 'immobile-source-page' );
2256                         }
2257                 } elseif ( $action == 'move-target' ) {
2258                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2259                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2260                         } elseif ( !$this->isMovable() ) {
2261                                 $errors[] = array( 'immobile-target-page' );
2262                         }
2263                 } elseif ( $action == 'delete' ) {
2264                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, array(), $rigor, true );
2265                         if ( !$tempErrors ) {
2266                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2267                                         $user, $tempErrors, $rigor, true );
2268                         }
2269                         if ( $tempErrors ) {
2270                                 // If protection keeps them from editing, they shouldn't be able to delete.
2271                                 $errors[] = array( 'deleteprotected' );
2272                         }
2273                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2274                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2275                         ) {
2276                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2277                         }
2278                 }
2279                 return $errors;
2280         }
2281
2282         /**
2283          * Check that the user isn't blocked from editing.
2284          *
2285          * @param string $action The action to check
2286          * @param User $user User to check
2287          * @param array $errors List of current errors
2288          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2289          * @param bool $short Short circuit on first error
2290          *
2291          * @return array List of errors
2292          */
2293         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2294                 // Account creation blocks handled at userlogin.
2295                 // Unblocking handled in SpecialUnblock
2296                 if ( $rigor === 'quick' || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2297                         return $errors;
2298                 }
2299
2300                 global $wgEmailConfirmToEdit;
2301
2302                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2303                         $errors[] = array( 'confirmedittext' );
2304                 }
2305
2306                 $useSlave = ( $rigor !== 'secure' );
2307                 if ( ( $action == 'edit' || $action == 'create' )
2308                         && !$user->isBlockedFrom( $this, $useSlave )
2309                 ) {
2310                         // Don't block the user from editing their own talk page unless they've been
2311                         // explicitly blocked from that too.
2312                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2313                         // @todo FIXME: Pass the relevant context into this function.
2314                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2315                 }
2316
2317                 return $errors;
2318         }
2319
2320         /**
2321          * Check that the user is allowed to read this page.
2322          *
2323          * @param string $action The action to check
2324          * @param User $user User to check
2325          * @param array $errors List of current errors
2326          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2327          * @param bool $short Short circuit on first error
2328          *
2329          * @return array List of errors
2330          */
2331         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2332                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2333
2334                 $whitelisted = false;
2335                 if ( User::isEveryoneAllowed( 'read' ) ) {
2336                         # Shortcut for public wikis, allows skipping quite a bit of code
2337                         $whitelisted = true;
2338                 } elseif ( $user->isAllowed( 'read' ) ) {
2339                         # If the user is allowed to read pages, he is allowed to read all pages
2340                         $whitelisted = true;
2341                 } elseif ( $this->isSpecial( 'Userlogin' )
2342                         || $this->isSpecial( 'ChangePassword' )
2343                         || $this->isSpecial( 'PasswordReset' )
2344                 ) {
2345                         # Always grant access to the login page.
2346                         # Even anons need to be able to log in.
2347                         $whitelisted = true;
2348                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2349                         # Time to check the whitelist
2350                         # Only do these checks is there's something to check against
2351                         $name = $this->getPrefixedText();
2352                         $dbName = $this->getPrefixedDBkey();
2353
2354                         // Check for explicit whitelisting with and without underscores
2355                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2356                                 $whitelisted = true;
2357                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2358                                 # Old settings might have the title prefixed with
2359                                 # a colon for main-namespace pages
2360                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2361                                         $whitelisted = true;
2362                                 }
2363                         } elseif ( $this->isSpecialPage() ) {
2364                                 # If it's a special page, ditch the subpage bit and check again
2365                                 $name = $this->getDBkey();
2366                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2367                                 if ( $name ) {
2368                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2369                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2370                                                 $whitelisted = true;
2371                                         }
2372                                 }
2373                         }
2374                 }
2375
2376                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2377                         $name = $this->getPrefixedText();
2378                         // Check for regex whitelisting
2379                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2380                                 if ( preg_match( $listItem, $name ) ) {
2381                                         $whitelisted = true;
2382                                         break;
2383                                 }
2384                         }
2385                 }
2386
2387                 if ( !$whitelisted ) {
2388                         # If the title is not whitelisted, give extensions a chance to do so...
2389                         Hooks::run( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2390                         if ( !$whitelisted ) {
2391                                 $errors[] = $this->missingPermissionError( $action, $short );
2392                         }
2393                 }
2394
2395                 return $errors;
2396         }
2397
2398         /**
2399          * Get a description array when the user doesn't have the right to perform
2400          * $action (i.e. when User::isAllowed() returns false)
2401          *
2402          * @param string $action The action to check
2403          * @param bool $short Short circuit on first error
2404          * @return array List of errors
2405          */
2406         private function missingPermissionError( $action, $short ) {
2407                 // We avoid expensive display logic for quickUserCan's and such
2408                 if ( $short ) {
2409                         return array( 'badaccess-group0' );
2410                 }
2411
2412                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2413                         User::getGroupsWithPermission( $action ) );
2414
2415                 if ( count( $groups ) ) {
2416                         global $wgLang;
2417                         return array(
2418                                 'badaccess-groups',
2419                                 $wgLang->commaList( $groups ),
2420                                 count( $groups )
2421                         );
2422                 } else {
2423                         return array( 'badaccess-group0' );
2424                 }
2425         }
2426
2427         /**
2428          * Can $user perform $action on this page? This is an internal function,
2429          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2430          * checks on wfReadOnly() and blocks)
2431          *
2432          * @param string $action Action that permission needs to be checked for
2433          * @param User $user User to check
2434          * @param string $rigor One of (quick,full,secure)
2435          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
2436          *   - full   : does cheap and expensive checks possibly from a slave
2437          *   - secure : does cheap and expensive checks, using the master as needed
2438          * @param bool $short Set this to true to stop after the first permission error.
2439          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2440          */
2441         protected function getUserPermissionsErrorsInternal(
2442                 $action, $user, $rigor = 'secure', $short = false
2443         ) {
2444                 if ( $rigor === true ) {
2445                         $rigor = 'secure'; // b/c
2446                 } elseif ( $rigor === false ) {
2447                         $rigor = 'quick'; // b/c
2448                 } elseif ( !in_array( $rigor, array( 'quick', 'full', 'secure' ) ) ) {
2449                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2450                 }
2451
2452                 # Read has special handling
2453                 if ( $action == 'read' ) {
2454                         $checks = array(
2455                                 'checkPermissionHooks',
2456                                 'checkReadPermissions',
2457                         );
2458                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2459                 # here as it will lead to duplicate error messages. This is okay to do
2460                 # since anywhere that checks for create will also check for edit, and
2461                 # those checks are called for edit.
2462                 } elseif ( $action == 'create' ) {
2463                         $checks = array(
2464                                 'checkQuickPermissions',
2465                                 'checkPermissionHooks',
2466                                 'checkPageRestrictions',
2467                                 'checkCascadingSourcesRestrictions',
2468                                 'checkActionPermissions',
2469                                 'checkUserBlock'
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, $rigor, $short );
2489                 }
2490
2491                 return $errors;
2492         }
2493
2494         /**
2495          * Get a filtered list of all restriction types supported by this wiki.
2496          * @param bool $exists True to get all restriction types that apply to
2497          * titles that do exist, False for all restriction types that apply to
2498          * titles that do not exist
2499          * @return array
2500          */
2501         public static function getFilteredRestrictionTypes( $exists = true ) {
2502                 global $wgRestrictionTypes;
2503                 $types = $wgRestrictionTypes;
2504                 if ( $exists ) {
2505                         # Remove the create restriction for existing titles
2506                         $types = array_diff( $types, array( 'create' ) );
2507                 } else {
2508                         # Only the create and upload restrictions apply to non-existing titles
2509                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2510                 }
2511                 return $types;
2512         }
2513
2514         /**
2515          * Returns restriction types for the current Title
2516          *
2517          * @return array Applicable restriction types
2518          */
2519         public function getRestrictionTypes() {
2520                 if ( $this->isSpecialPage() ) {
2521                         return array();
2522                 }
2523
2524                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2525
2526                 if ( $this->getNamespace() != NS_FILE ) {
2527                         # Remove the upload restriction for non-file titles
2528                         $types = array_diff( $types, array( 'upload' ) );
2529                 }
2530
2531                 Hooks::run( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2532
2533                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2534                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2535
2536                 return $types;
2537         }
2538
2539         /**
2540          * Is this title subject to title protection?
2541          * Title protection is the one applied against creation of such title.
2542          *
2543          * @return array|bool An associative array representing any existent title
2544          *   protection, or false if there's none.
2545          */
2546         public function getTitleProtection() {
2547                 // Can't protect pages in special namespaces
2548                 if ( $this->getNamespace() < 0 ) {
2549                         return false;
2550                 }
2551
2552                 // Can't protect pages that exist.
2553                 if ( $this->exists() ) {
2554                         return false;
2555                 }
2556
2557                 if ( $this->mTitleProtection === null ) {
2558                         $dbr = wfGetDB( DB_SLAVE );
2559                         $res = $dbr->select(
2560                                 'protected_titles',
2561                                 array(
2562                                         'user' => 'pt_user',
2563                                         'reason' => 'pt_reason',
2564                                         'expiry' => 'pt_expiry',
2565                                         'permission' => 'pt_create_perm'
2566                                 ),
2567                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2568                                 __METHOD__
2569                         );
2570
2571                         // fetchRow returns false if there are no rows.
2572                         $row = $dbr->fetchRow( $res );
2573                         if ( $row ) {
2574                                 if ( $row['permission'] == 'sysop' ) {
2575                                         $row['permission'] = 'editprotected'; // B/C
2576                                 }
2577                                 if ( $row['permission'] == 'autoconfirmed' ) {
2578                                         $row['permission'] = 'editsemiprotected'; // B/C
2579                                 }
2580                         }
2581                         $this->mTitleProtection = $row;
2582                 }
2583                 return $this->mTitleProtection;
2584         }
2585
2586         /**
2587          * Remove any title protection due to page existing
2588          */
2589         public function deleteTitleProtection() {
2590                 $dbw = wfGetDB( DB_MASTER );
2591
2592                 $dbw->delete(
2593                         'protected_titles',
2594                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2595                         __METHOD__
2596                 );
2597                 $this->mTitleProtection = false;
2598         }
2599
2600         /**
2601          * Is this page "semi-protected" - the *only* protection levels are listed
2602          * in $wgSemiprotectedRestrictionLevels?
2603          *
2604          * @param string $action Action to check (default: edit)
2605          * @return bool
2606          */
2607         public function isSemiProtected( $action = 'edit' ) {
2608                 global $wgSemiprotectedRestrictionLevels;
2609
2610                 $restrictions = $this->getRestrictions( $action );
2611                 $semi = $wgSemiprotectedRestrictionLevels;
2612                 if ( !$restrictions || !$semi ) {
2613                         // Not protected, or all protection is full protection
2614                         return false;
2615                 }
2616
2617                 // Remap autoconfirmed to editsemiprotected for BC
2618                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2619                         $semi[$key] = 'editsemiprotected';
2620                 }
2621                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2622                         $restrictions[$key] = 'editsemiprotected';
2623                 }
2624
2625                 return !array_diff( $restrictions, $semi );
2626         }
2627
2628         /**
2629          * Does the title correspond to a protected article?
2630          *
2631          * @param string $action The action the page is protected from,
2632          * by default checks all actions.
2633          * @return bool
2634          */
2635         public function isProtected( $action = '' ) {
2636                 global $wgRestrictionLevels;
2637
2638                 $restrictionTypes = $this->getRestrictionTypes();
2639
2640                 # Special pages have inherent protection
2641                 if ( $this->isSpecialPage() ) {
2642                         return true;
2643                 }
2644
2645                 # Check regular protection levels
2646                 foreach ( $restrictionTypes as $type ) {
2647                         if ( $action == $type || $action == '' ) {
2648                                 $r = $this->getRestrictions( $type );
2649                                 foreach ( $wgRestrictionLevels as $level ) {
2650                                         if ( in_array( $level, $r ) && $level != '' ) {
2651                                                 return true;
2652                                         }
2653                                 }
2654                         }
2655                 }
2656
2657                 return false;
2658         }
2659
2660         /**
2661          * Determines if $user is unable to edit this page because it has been protected
2662          * by $wgNamespaceProtection.
2663          *
2664          * @param User $user User object to check permissions
2665          * @return bool
2666          */
2667         public function isNamespaceProtected( User $user ) {
2668                 global $wgNamespaceProtection;
2669
2670                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2671                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2672                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2673                                         return true;
2674                                 }
2675                         }
2676                 }
2677                 return false;
2678         }
2679
2680         /**
2681          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2682          *
2683          * @return bool If the page is subject to cascading restrictions.
2684          */
2685         public function isCascadeProtected() {
2686                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2687                 return ( $sources > 0 );
2688         }
2689
2690         /**
2691          * Determines whether cascading protection sources have already been loaded from
2692          * the database.
2693          *
2694          * @param bool $getPages True to check if the pages are loaded, or false to check
2695          * if the status is loaded.
2696          * @return bool Whether or not the specified information has been loaded
2697          * @since 1.23
2698          */
2699         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2700                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2701         }
2702
2703         /**
2704          * Cascading protection: Get the source of any cascading restrictions on this page.
2705          *
2706          * @param bool $getPages Whether or not to retrieve the actual pages
2707          *        that the restrictions have come from and the actual restrictions
2708          *        themselves.
2709          * @return array Two elements: First is an array of Title objects of the
2710          *        pages from which cascading restrictions have come, false for
2711          *        none, or true if such restrictions exist but $getPages was not
2712          *        set. Second is an array like that returned by
2713          *        Title::getAllRestrictions(), or an empty array if $getPages is
2714          *        false.
2715          */
2716         public function getCascadeProtectionSources( $getPages = true ) {
2717                 global $wgContLang;
2718                 $pagerestrictions = array();
2719
2720                 if ( $this->mCascadeSources !== null && $getPages ) {
2721                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2722                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2723                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2724                 }
2725
2726                 $dbr = wfGetDB( DB_SLAVE );
2727
2728                 if ( $this->getNamespace() == NS_FILE ) {
2729                         $tables = array( 'imagelinks', 'page_restrictions' );
2730                         $where_clauses = array(
2731                                 'il_to' => $this->getDBkey(),
2732                                 'il_from=pr_page',
2733                                 'pr_cascade' => 1
2734                         );
2735                 } else {
2736                         $tables = array( 'templatelinks', 'page_restrictions' );
2737                         $where_clauses = array(
2738                                 'tl_namespace' => $this->getNamespace(),
2739                                 'tl_title' => $this->getDBkey(),
2740                                 'tl_from=pr_page',
2741                                 'pr_cascade' => 1
2742                         );
2743                 }
2744
2745                 if ( $getPages ) {
2746                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2747                                 'pr_expiry', 'pr_type', 'pr_level' );
2748                         $where_clauses[] = 'page_id=pr_page';
2749                         $tables[] = 'page';
2750                 } else {
2751                         $cols = array( 'pr_expiry' );
2752                 }
2753
2754                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2755
2756                 $sources = $getPages ? array() : false;
2757                 $now = wfTimestampNow();
2758
2759                 foreach ( $res as $row ) {
2760                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2761                         if ( $expiry > $now ) {
2762                                 if ( $getPages ) {
2763                                         $page_id = $row->pr_page;
2764                                         $page_ns = $row->page_namespace;
2765                                         $page_title = $row->page_title;
2766                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2767                                         # Add groups needed for each restriction type if its not already there
2768                                         # Make sure this restriction type still exists
2769
2770                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2771                                                 $pagerestrictions[$row->pr_type] = array();
2772                                         }
2773
2774                                         if (
2775                                                 isset( $pagerestrictions[$row->pr_type] )
2776                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2777                                         ) {
2778                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2779                                         }
2780                                 } else {
2781                                         $sources = true;
2782                                 }
2783                         }
2784                 }
2785
2786                 if ( $getPages ) {
2787                         $this->mCascadeSources = $sources;
2788                         $this->mCascadingRestrictions = $pagerestrictions;
2789                 } else {
2790                         $this->mHasCascadingRestrictions = $sources;
2791                 }
2792
2793                 return array( $sources, $pagerestrictions );
2794         }
2795
2796         /**
2797          * Accessor for mRestrictionsLoaded
2798          *
2799          * @return bool Whether or not the page's restrictions have already been
2800          * loaded from the database
2801          * @since 1.23
2802          */
2803         public function areRestrictionsLoaded() {
2804                 return $this->mRestrictionsLoaded;
2805         }
2806
2807         /**
2808          * Accessor/initialisation for mRestrictions
2809          *
2810          * @param string $action Action that permission needs to be checked for
2811          * @return array Restriction levels needed to take the action. All levels are
2812          *     required. Note that restriction levels are normally user rights, but 'sysop'
2813          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2814          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2815          */
2816         public function getRestrictions( $action ) {
2817                 if ( !$this->mRestrictionsLoaded ) {
2818                         $this->loadRestrictions();
2819                 }
2820                 return isset( $this->mRestrictions[$action] )
2821                                 ? $this->mRestrictions[$action]
2822                                 : array();
2823         }
2824
2825         /**
2826          * Accessor/initialisation for mRestrictions
2827          *
2828          * @return array Keys are actions, values are arrays as returned by
2829          *     Title::getRestrictions()
2830          * @since 1.23
2831          */
2832         public function getAllRestrictions() {
2833                 if ( !$this->mRestrictionsLoaded ) {
2834                         $this->loadRestrictions();
2835                 }
2836                 return $this->mRestrictions;
2837         }
2838
2839         /**
2840          * Get the expiry time for the restriction against a given action
2841          *
2842          * @param string $action
2843          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2844          *     or not protected at all, or false if the action is not recognised.
2845          */
2846         public function getRestrictionExpiry( $action ) {
2847                 if ( !$this->mRestrictionsLoaded ) {
2848                         $this->loadRestrictions();
2849                 }
2850                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2851         }
2852
2853         /**
2854          * Returns cascading restrictions for the current article
2855          *
2856          * @return bool
2857          */
2858         function areRestrictionsCascading() {
2859                 if ( !$this->mRestrictionsLoaded ) {
2860                         $this->loadRestrictions();
2861                 }
2862
2863                 return $this->mCascadeRestriction;
2864         }
2865
2866         /**
2867          * Loads a string into mRestrictions array
2868          *
2869          * @param ResultWrapper $res Resource restrictions as an SQL result.
2870          * @param string $oldFashionedRestrictions Comma-separated list of page
2871          *        restrictions from page table (pre 1.10)
2872          */
2873         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2874                 $rows = array();
2875
2876                 foreach ( $res as $row ) {
2877                         $rows[] = $row;
2878                 }
2879
2880                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2881         }
2882
2883         /**
2884          * Compiles list of active page restrictions from both page table (pre 1.10)
2885          * and page_restrictions table for this existing page.
2886          * Public for usage by LiquidThreads.
2887          *
2888          * @param array $rows Array of db result objects
2889          * @param string $oldFashionedRestrictions Comma-separated list of page
2890          *   restrictions from page table (pre 1.10)
2891          */
2892         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2893                 global $wgContLang;
2894                 $dbr = wfGetDB( DB_SLAVE );
2895
2896                 $restrictionTypes = $this->getRestrictionTypes();
2897
2898                 foreach ( $restrictionTypes as $type ) {
2899                         $this->mRestrictions[$type] = array();
2900                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2901                 }
2902
2903                 $this->mCascadeRestriction = false;
2904
2905                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2906                 if ( $oldFashionedRestrictions !== null ) {
2907                         $this->mOldRestrictions = $oldFashionedRestrictions;
2908                 }
2909
2910                 if ( $this->mOldRestrictions === false ) {
2911                         $this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2912                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2913                 }
2914
2915                 if ( $this->mOldRestrictions != '' ) {
2916                         foreach ( explode( ':', trim( $this->mOldRestrictions ) ) as $restrict ) {
2917                                 $temp = explode( '=', trim( $restrict ) );
2918                                 if ( count( $temp ) == 1 ) {
2919                                         // old old format should be treated as edit/move restriction
2920                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2921                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2922                                 } else {
2923                                         $restriction = trim( $temp[1] );
2924                                         if ( $restriction != '' ) { //some old entries are empty
2925                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2926                                         }
2927                                 }
2928                         }
2929                 }
2930
2931                 if ( count( $rows ) ) {
2932                         # Current system - load second to make them override.
2933                         $now = wfTimestampNow();
2934
2935                         # Cycle through all the restrictions.
2936                         foreach ( $rows as $row ) {
2937
2938                                 // Don't take care of restrictions types that aren't allowed
2939                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2940                                         continue;
2941                                 }
2942
2943                                 // This code should be refactored, now that it's being used more generally,
2944                                 // But I don't really see any harm in leaving it in Block for now -werdna
2945                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2946
2947                                 // Only apply the restrictions if they haven't expired!
2948                                 if ( !$expiry || $expiry > $now ) {
2949                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2950                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2951
2952                                         $this->mCascadeRestriction |= $row->pr_cascade;
2953                                 }
2954                         }
2955                 }
2956
2957                 $this->mRestrictionsLoaded = true;
2958         }
2959
2960         /**
2961          * Load restrictions from the page_restrictions table
2962          *
2963          * @param string $oldFashionedRestrictions Comma-separated list of page
2964          *   restrictions from page table (pre 1.10)
2965          */
2966         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2967                 global $wgContLang;
2968                 if ( !$this->mRestrictionsLoaded ) {
2969                         if ( $this->exists() ) {
2970                                 $dbr = wfGetDB( DB_SLAVE );
2971
2972                                 $res = $dbr->select(
2973                                         'page_restrictions',
2974                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2975                                         array( 'pr_page' => $this->getArticleID() ),
2976                                         __METHOD__
2977                                 );
2978
2979                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2980                         } else {
2981                                 $title_protection = $this->getTitleProtection();
2982
2983                                 if ( $title_protection ) {
2984                                         $now = wfTimestampNow();
2985                                         $expiry = $wgContLang->formatExpiry( $title_protection['expiry'], TS_MW );
2986
2987                                         if ( !$expiry || $expiry > $now ) {
2988                                                 // Apply the restrictions
2989                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2990                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
2991                                         } else { // Get rid of the old restrictions
2992                                                 $this->mTitleProtection = false;
2993                                         }
2994                                 } else {
2995                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2996                                 }
2997                                 $this->mRestrictionsLoaded = true;
2998                         }
2999                 }
3000         }
3001
3002         /**
3003          * Flush the protection cache in this object and force reload from the database.
3004          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3005          */
3006         public function flushRestrictions() {
3007                 $this->mRestrictionsLoaded = false;
3008                 $this->mTitleProtection = null;
3009         }
3010
3011         /**
3012          * Purge expired restrictions from the page_restrictions table
3013          */
3014         static function purgeExpiredRestrictions() {
3015                 if ( wfReadOnly() ) {
3016                         return;
3017                 }
3018
3019                 $method = __METHOD__;
3020                 $dbw = wfGetDB( DB_MASTER );
3021                 $dbw->onTransactionIdle( function () use ( $dbw, $method ) {
3022                         $dbw->delete(
3023                                 'page_restrictions',
3024                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3025                                 $method
3026                         );
3027                         $dbw->delete(
3028                                 'protected_titles',
3029                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3030                                 $method
3031                         );
3032                 } );
3033         }
3034
3035         /**
3036          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3037          *
3038          * @return bool
3039          */
3040         public function hasSubpages() {
3041                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3042                         # Duh
3043                         return false;
3044                 }
3045
3046                 # We dynamically add a member variable for the purpose of this method
3047                 # alone to cache the result.  There's no point in having it hanging
3048                 # around uninitialized in every Title object; therefore we only add it
3049                 # if needed and don't declare it statically.
3050                 if ( $this->mHasSubpages === null ) {
3051                         $this->mHasSubpages = false;
3052                         $subpages = $this->getSubpages( 1 );
3053                         if ( $subpages instanceof TitleArray ) {
3054                                 $this->mHasSubpages = (bool)$subpages->count();
3055                         }
3056                 }
3057
3058                 return $this->mHasSubpages;
3059         }
3060
3061         /**
3062          * Get all subpages of this page.
3063          *
3064          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3065          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3066          *  doesn't allow subpages
3067          */
3068         public function getSubpages( $limit = -1 ) {
3069                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3070                         return array();
3071                 }
3072
3073                 $dbr = wfGetDB( DB_SLAVE );
3074                 $conds['page_namespace'] = $this->getNamespace();
3075                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3076                 $options = array();
3077                 if ( $limit > -1 ) {
3078                         $options['LIMIT'] = $limit;
3079                 }
3080                 $this->mSubpages = TitleArray::newFromResult(
3081                         $dbr->select( 'page',
3082                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3083                                 $conds,
3084                                 __METHOD__,
3085                                 $options
3086                         )
3087                 );
3088                 return $this->mSubpages;
3089         }
3090
3091         /**
3092          * Is there a version of this page in the deletion archive?
3093          *
3094          * @return int The number of archived revisions
3095          */
3096         public function isDeleted() {
3097                 if ( $this->getNamespace() < 0 ) {
3098                         $n = 0;
3099                 } else {
3100                         $dbr = wfGetDB( DB_SLAVE );
3101
3102                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3103                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3104                                 __METHOD__
3105                         );
3106                         if ( $this->getNamespace() == NS_FILE ) {
3107                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3108                                         array( 'fa_name' => $this->getDBkey() ),
3109                                         __METHOD__
3110                                 );
3111                         }
3112                 }
3113                 return (int)$n;
3114         }
3115
3116         /**
3117          * Is there a version of this page in the deletion archive?
3118          *
3119          * @return bool
3120          */
3121         public function isDeletedQuick() {
3122                 if ( $this->getNamespace() < 0 ) {
3123                         return false;
3124                 }
3125                 $dbr = wfGetDB( DB_SLAVE );
3126                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3127                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3128                         __METHOD__
3129                 );
3130                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3131                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3132                                 array( 'fa_name' => $this->getDBkey() ),
3133                                 __METHOD__
3134                         );
3135                 }
3136                 return $deleted;
3137         }
3138
3139         /**
3140          * Get the article ID for this Title from the link cache,
3141          * adding it if necessary
3142          *
3143          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3144          *  for update
3145          * @return int The ID
3146          */
3147         public function getArticleID( $flags = 0 ) {
3148                 if ( $this->getNamespace() < 0 ) {
3149                         $this->mArticleID = 0;
3150                         return $this->mArticleID;
3151                 }
3152                 $linkCache = LinkCache::singleton();
3153                 if ( $flags & self::GAID_FOR_UPDATE ) {
3154                         $oldUpdate = $linkCache->forUpdate( true );
3155                         $linkCache->clearLink( $this );
3156                         $this->mArticleID = $linkCache->addLinkObj( $this );
3157                         $linkCache->forUpdate( $oldUpdate );
3158                 } else {
3159                         if ( -1 == $this->mArticleID ) {
3160                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3161                         }
3162                 }
3163                 return $this->mArticleID;
3164         }
3165
3166         /**
3167          * Is this an article that is a redirect page?
3168          * Uses link cache, adding it if necessary
3169          *
3170          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3171          * @return bool
3172          */
3173         public function isRedirect( $flags = 0 ) {
3174                 if ( !is_null( $this->mRedirect ) ) {
3175                         return $this->mRedirect;
3176                 }
3177                 if ( !$this->getArticleID( $flags ) ) {
3178                         $this->mRedirect = false;
3179                         return $this->mRedirect;
3180                 }
3181
3182                 $linkCache = LinkCache::singleton();
3183                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3184                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3185                 if ( $cached === null ) {
3186                         # Trust LinkCache's state over our own
3187                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3188                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3189                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3190                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3191                         # LinkCache to refresh its data from the master.
3192                         $this->mRedirect = false;
3193                         return $this->mRedirect;
3194                 }
3195
3196                 $this->mRedirect = (bool)$cached;
3197
3198                 return $this->mRedirect;
3199         }
3200
3201         /**
3202          * What is the length of this page?
3203          * Uses link cache, adding it if necessary
3204          *
3205          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3206          * @return int
3207          */
3208         public function getLength( $flags = 0 ) {
3209                 if ( $this->mLength != -1 ) {
3210                         return $this->mLength;
3211                 }
3212                 if ( !$this->getArticleID( $flags ) ) {
3213                         $this->mLength = 0;
3214                         return $this->mLength;
3215                 }
3216                 $linkCache = LinkCache::singleton();
3217                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3218                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3219                 if ( $cached === null ) {
3220                         # Trust LinkCache's state over our own, as for isRedirect()
3221                         $this->mLength = 0;
3222                         return $this->mLength;
3223                 }
3224
3225                 $this->mLength = intval( $cached );
3226
3227                 return $this->mLength;
3228         }
3229
3230         /**
3231          * What is the page_latest field for this page?
3232          *
3233          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3234          * @return int Int or 0 if the page doesn't exist
3235          */
3236         public function getLatestRevID( $flags = 0 ) {
3237                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3238                         return intval( $this->mLatestID );
3239                 }
3240                 if ( !$this->getArticleID( $flags ) ) {
3241                         $this->mLatestID = 0;
3242                         return $this->mLatestID;
3243                 }
3244                 $linkCache = LinkCache::singleton();
3245                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3246                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3247                 if ( $cached === null ) {
3248                         # Trust LinkCache's state over our own, as for isRedirect()
3249                         $this->mLatestID = 0;
3250                         return $this->mLatestID;
3251                 }
3252
3253                 $this->mLatestID = intval( $cached );
3254
3255                 return $this->mLatestID;
3256         }
3257
3258         /**
3259          * This clears some fields in this object, and clears any associated
3260          * keys in the "bad links" section of the link cache.
3261          *
3262          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3263          * loading of the new page_id. It's also called from
3264          * WikiPage::doDeleteArticleReal()
3265          *
3266          * @param int $newid The new Article ID
3267          */
3268         public function resetArticleID( $newid ) {
3269                 $linkCache = LinkCache::singleton();
3270                 $linkCache->clearLink( $this );
3271
3272                 if ( $newid === false ) {
3273                         $this->mArticleID = -1;
3274                 } else {
3275                         $this->mArticleID = intval( $newid );
3276                 }
3277                 $this->mRestrictionsLoaded = false;
3278                 $this->mRestrictions = array();
3279                 $this->mOldRestrictions = false;
3280                 $this->mRedirect = null;
3281                 $this->mLength = -1;
3282                 $this->mLatestID = false;
3283                 $this->mContentModel = false;
3284                 $this->mEstimateRevisions = null;
3285                 $this->mPageLanguage = false;
3286                 $this->mDbPageLanguage = null;
3287                 $this->mIsBigDeletion = null;
3288         }
3289
3290         /**
3291          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3292          *
3293          * @param string $text Containing title to capitalize
3294          * @param int $ns Namespace index, defaults to NS_MAIN
3295          * @return string Containing capitalized title
3296          */
3297         public static function capitalize( $text, $ns = NS_MAIN ) {
3298                 global $wgContLang;
3299
3300                 if ( MWNamespace::isCapitalized( $ns ) ) {
3301                         return $wgContLang->ucfirst( $text );
3302                 } else {
3303                         return $text;
3304                 }
3305         }
3306
3307         /**
3308          * Secure and split - main initialisation function for this object
3309          *
3310          * Assumes that mDbkeyform has been set, and is urldecoded
3311          * and uses underscores, but not otherwise munged.  This function
3312          * removes illegal characters, splits off the interwiki and
3313          * namespace prefixes, sets the other forms, and canonicalizes
3314          * everything.
3315          *
3316          * @return bool True on success
3317          */
3318         private function secureAndSplit() {
3319                 # Initialisation
3320                 $this->mInterwiki = '';
3321                 $this->mFragment = '';
3322                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3323
3324                 $dbkey = $this->mDbkeyform;
3325
3326                 try {
3327                         // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3328                         //        the parsing code with Title, while avoiding massive refactoring.
3329                         // @todo: get rid of secureAndSplit, refactor parsing code.
3330                         $titleParser = self::getTitleParser();
3331                         $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3332                 } catch ( MalformedTitleException $ex ) {
3333                         return false;
3334                 }
3335
3336                 # Fill fields
3337                 $this->setFragment( '#' . $parts['fragment'] );
3338                 $this->mInterwiki = $parts['interwiki'];
3339                 $this->mLocalInterwiki = $parts['local_interwiki'];
3340                 $this->mNamespace = $parts['namespace'];
3341                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3342
3343                 $this->mDbkeyform = $parts['dbkey'];
3344                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3345                 $this->mTextform = str_replace( '_', ' ', $this->mDbkeyform );
3346
3347                 # We already know that some pages won't be in the database!
3348                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3349                         $this->mArticleID = 0;
3350                 }
3351
3352                 return true;
3353         }
3354
3355         /**
3356          * Get an array of Title objects linking to this Title
3357          * Also stores the IDs in the link cache.
3358          *
3359          * WARNING: do not use this function on arbitrary user-supplied titles!
3360          * On heavily-used templates it will max out the memory.
3361          *
3362          * @param array $options May be FOR UPDATE
3363          * @param string $table Table name
3364          * @param string $prefix Fields prefix
3365          * @return Title[] Array of Title objects linking here
3366          */
3367         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3368                 if ( count( $options ) > 0 ) {
3369                         $db = wfGetDB( DB_MASTER );
3370                 } else {
3371                         $db = wfGetDB( DB_SLAVE );
3372                 }
3373
3374                 $res = $db->select(
3375                         array( 'page', $table ),
3376                         self::getSelectFields(),
3377                         array(
3378                                 "{$prefix}_from=page_id",
3379                                 "{$prefix}_namespace" => $this->getNamespace(),
3380                                 "{$prefix}_title" => $this->getDBkey() ),
3381                         __METHOD__,
3382                         $options
3383                 );
3384
3385                 $retVal = array();
3386                 if ( $res->numRows() ) {
3387                         $linkCache = LinkCache::singleton();
3388                         foreach ( $res as $row ) {
3389                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3390                                 if ( $titleObj ) {
3391                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3392                                         $retVal[] = $titleObj;
3393                                 }
3394                         }
3395                 }
3396                 return $retVal;
3397         }
3398
3399         /**
3400          * Get an array of Title objects using this Title as a template
3401          * Also stores the IDs in the link cache.
3402          *
3403          * WARNING: do not use this function on arbitrary user-supplied titles!
3404          * On heavily-used templates it will max out the memory.
3405          *
3406          * @param array $options May be FOR UPDATE
3407          * @return Title[] Array of Title the Title objects linking here
3408          */
3409         public function getTemplateLinksTo( $options = array() ) {
3410                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3411         }
3412
3413         /**
3414          * Get an array of Title objects linked from this Title
3415          * Also stores the IDs in the link cache.
3416          *
3417          * WARNING: do not use this function on arbitrary user-supplied titles!
3418          * On heavily-used templates it will max out the memory.
3419          *
3420          * @param array $options May be FOR UPDATE
3421          * @param string $table Table name
3422          * @param string $prefix Fields prefix
3423          * @return array Array of Title objects linking here
3424          */
3425         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3426                 $id = $this->getArticleID();
3427
3428                 # If the page doesn't exist; there can't be any link from this page
3429                 if ( !$id ) {
3430                         return array();
3431                 }
3432
3433                 if ( count( $options ) > 0 ) {
3434                         $db = wfGetDB( DB_MASTER );
3435                 } else {
3436                         $db = wfGetDB( DB_SLAVE );
3437                 }
3438
3439                 $blNamespace = "{$prefix}_namespace";
3440                 $blTitle = "{$prefix}_title";
3441
3442                 $res = $db->select(
3443                         array( $table, 'page' ),
3444                         array_merge(
3445                                 array( $blNamespace, $blTitle ),
3446                                 WikiPage::selectFields()
3447                         ),
3448                         array( "{$prefix}_from" => $id ),
3449                         __METHOD__,
3450                         $options,
3451                         array( 'page' => array(
3452                                 'LEFT JOIN',
3453                                 array( "page_namespace=$blNamespace", "page_title=$blTitle" )
3454                         ) )
3455                 );
3456
3457                 $retVal = array();
3458                 $linkCache = LinkCache::singleton();
3459                 foreach ( $res as $row ) {
3460                         if ( $row->page_id ) {
3461                                 $titleObj = Title::newFromRow( $row );
3462                         } else {
3463                                 $titleObj = Title::makeTitle( $row->$blNamespace, $row->$blTitle );
3464                                 $linkCache->addBadLinkObj( $titleObj );
3465                         }
3466                         $retVal[] = $titleObj;
3467                 }
3468
3469                 return $retVal;
3470         }
3471
3472         /**
3473          * Get an array of Title objects used on this Title as a template
3474          * Also stores the IDs in the link cache.
3475          *
3476          * WARNING: do not use this function on arbitrary user-supplied titles!
3477          * On heavily-used templates it will max out the memory.
3478          *
3479          * @param array $options May be FOR UPDATE
3480          * @return Title[] Array of Title the Title objects used here
3481          */
3482         public function getTemplateLinksFrom( $options = array() ) {
3483                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3484         }
3485
3486         /**
3487          * Get an array of Title objects referring to non-existent articles linked
3488          * from this page.
3489          *
3490          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3491          *   should use redirect table in this case).
3492          * @return Title[] Array of Title the Title objects
3493          */
3494         public function getBrokenLinksFrom() {
3495                 if ( $this->getArticleID() == 0 ) {
3496                         # All links from article ID 0 are false positives
3497                         return array();
3498                 }
3499
3500                 $dbr = wfGetDB( DB_SLAVE );
3501                 $res = $dbr->select(
3502                         array( 'page', 'pagelinks' ),
3503                         array( 'pl_namespace', 'pl_title' ),
3504                         array(
3505                                 'pl_from' => $this->getArticleID(),
3506                                 'page_namespace IS NULL'
3507                         ),
3508                         __METHOD__, array(),
3509                         array(
3510                                 'page' => array(
3511                                         'LEFT JOIN',
3512                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3513                                 )
3514                         )
3515                 );
3516
3517                 $retVal = array();
3518                 foreach ( $res as $row ) {
3519                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3520                 }
3521                 return $retVal;
3522         }
3523
3524         /**
3525          * Get a list of URLs to purge from the Squid cache when this
3526          * page changes
3527          *
3528          * @return string[] Array of String the URLs
3529          */
3530         public function getSquidURLs() {
3531                 $urls = array(
3532                         $this->getInternalURL(),
3533                         $this->getInternalURL( 'action=history' )
3534                 );
3535
3536                 $pageLang = $this->getPageLanguage();
3537                 if ( $pageLang->hasVariants() ) {
3538                         $variants = $pageLang->getVariants();
3539                         foreach ( $variants as $vCode ) {
3540                                 $urls[] = $this->getInternalURL( '', $vCode );
3541                         }
3542                 }
3543
3544                 // If we are looking at a css/js user subpage, purge the action=raw.
3545                 if ( $this->isJsSubpage() ) {
3546                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3547                 } elseif ( $this->isCssSubpage() ) {
3548                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3549                 }
3550
3551                 Hooks::run( 'TitleSquidURLs', array( $this, &$urls ) );
3552                 return $urls;
3553         }
3554
3555         /**
3556          * Purge all applicable Squid URLs
3557          */
3558         public function purgeSquid() {
3559                 global $wgUseSquid;
3560                 if ( $wgUseSquid ) {
3561                         $urls = $this->getSquidURLs();
3562                         $u = new SquidUpdate( $urls );
3563                         $u->doUpdate();
3564                 }
3565         }
3566
3567         /**
3568          * Move this page without authentication
3569          *
3570          * @deprecated since 1.25 use MovePage class instead
3571          * @param Title $nt The new page Title
3572          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3573          */
3574         public function moveNoAuth( &$nt ) {
3575                 wfDeprecated( __METHOD__, '1.25' );
3576                 return $this->moveTo( $nt, false );
3577         }
3578
3579         /**
3580          * Check whether a given move operation would be valid.
3581          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3582          *
3583          * @deprecated since 1.25, use MovePage's methods instead
3584          * @param Title $nt The new title
3585          * @param bool $auth Whether to check user permissions (uses $wgUser)
3586          * @param string $reason Is the log summary of the move, used for spam checking
3587          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3588          */
3589         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3590                 global $wgUser;
3591
3592                 if ( !( $nt instanceof Title ) ) {
3593                         // Normally we'd add this to $errors, but we'll get
3594                         // lots of syntax errors if $nt is not an object
3595                         return array( array( 'badtitletext' ) );
3596                 }
3597
3598                 $mp = new MovePage( $this, $nt );
3599                 $errors = $mp->isValidMove()->getErrorsArray();
3600                 if ( $auth ) {
3601                         $errors = wfMergeErrorArrays(
3602                                 $errors,
3603                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3604                         );
3605                 }
3606
3607                 return $errors ? : true;
3608         }
3609
3610         /**
3611          * Check if the requested move target is a valid file move target
3612          * @todo move this to MovePage
3613          * @param Title $nt Target title
3614          * @return array List of errors
3615          */
3616         protected function validateFileMoveOperation( $nt ) {
3617                 global $wgUser;
3618
3619                 $errors = array();
3620
3621                 $destFile = wfLocalFile( $nt );
3622                 $destFile->load( File::READ_LATEST );
3623                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3624                         && !$destFile->exists() && wfFindFile( $nt )
3625                 ) {
3626                         $errors[] = array( 'file-exists-sharedrepo' );
3627                 }
3628
3629                 return $errors;
3630         }
3631
3632         /**
3633          * Move a title to a new location
3634          *
3635          * @deprecated since 1.25, use the MovePage class instead
3636          * @param Title $nt The new title
3637          * @param bool $auth Indicates whether $wgUser's permissions
3638          *  should be checked
3639          * @param string $reason The reason for the move
3640          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3641          *  Ignored if the user doesn't have the suppressredirect right.
3642          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3643          */
3644         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3645                 global $wgUser;
3646                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3647                 if ( is_array( $err ) ) {
3648                         // Auto-block user's IP if the account was "hard" blocked
3649                         $wgUser->spreadAnyEditBlock();
3650                         return $err;
3651                 }
3652                 // Check suppressredirect permission
3653                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3654                         $createRedirect = true;
3655                 }
3656
3657                 $mp = new MovePage( $this, $nt );
3658                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3659                 if ( $status->isOK() ) {
3660                         return true;
3661                 } else {
3662                         return $status->getErrorsArray();
3663                 }
3664         }
3665
3666         /**
3667          * Move this page's subpages to be subpages of $nt
3668          *
3669          * @param Title $nt Move target
3670          * @param bool $auth Whether $wgUser's permissions should be checked
3671          * @param string $reason The reason for the move
3672          * @param bool $createRedirect Whether to create redirects from the old subpages to
3673          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3674          * @return array Array with old page titles as keys, and strings (new page titles) or
3675          *     arrays (errors) as values, or an error array with numeric indices if no pages
3676          *     were moved
3677          */
3678         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3679                 global $wgMaximumMovedPages;
3680                 // Check permissions
3681                 if ( !$this->userCan( 'move-subpages' ) ) {
3682                         return array( 'cant-move-subpages' );
3683                 }
3684                 // Do the source and target namespaces support subpages?
3685                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3686                         return array( 'namespace-nosubpages',
3687                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3688                 }
3689                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3690                         return array( 'namespace-nosubpages',
3691                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3692                 }
3693
3694                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3695                 $retval = array();
3696                 $count = 0;
3697                 foreach ( $subpages as $oldSubpage ) {
3698                         $count++;
3699                         if ( $count > $wgMaximumMovedPages ) {
3700                                 $retval[$oldSubpage->getPrefixedText()] =
3701                                                 array( 'movepage-max-pages',
3702                                                         $wgMaximumMovedPages );
3703                                 break;
3704                         }
3705
3706                         // We don't know whether this function was called before
3707                         // or after moving the root page, so check both
3708                         // $this and $nt
3709                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3710                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3711                         ) {
3712                                 // When moving a page to a subpage of itself,
3713                                 // don't move it twice
3714                                 continue;
3715                         }
3716                         $newPageName = preg_replace(
3717                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3718                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3719                                         $oldSubpage->getDBkey() );
3720                         if ( $oldSubpage->isTalkPage() ) {
3721                                 $newNs = $nt->getTalkPage()->getNamespace();
3722                         } else {
3723                                 $newNs = $nt->getSubjectPage()->getNamespace();
3724                         }
3725                         # Bug 14385: we need makeTitleSafe because the new page names may
3726                         # be longer than 255 characters.
3727                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3728
3729                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3730                         if ( $success === true ) {
3731                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3732                         } else {
3733                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3734                         }
3735                 }
3736                 return $retval;
3737         }
3738
3739         /**
3740          * Checks if this page is just a one-rev redirect.
3741          * Adds lock, so don't use just for light purposes.
3742          *
3743          * @return bool
3744          */
3745         public function isSingleRevRedirect() {
3746                 global $wgContentHandlerUseDB;
3747
3748                 $dbw = wfGetDB( DB_MASTER );
3749
3750                 # Is it a redirect?
3751                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3752                 if ( $wgContentHandlerUseDB ) {
3753                         $fields[] = 'page_content_model';
3754                 }
3755
3756                 $row = $dbw->selectRow( 'page',
3757                         $fields,
3758                         $this->pageCond(),
3759                         __METHOD__,
3760                         array( 'FOR UPDATE' )
3761                 );
3762                 # Cache some fields we may want
3763                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3764                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3765                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3766                 $this->mContentModel = $row && isset( $row->page_content_model )
3767                         ? strval( $row->page_content_model )
3768                         : false;
3769
3770                 if ( !$this->mRedirect ) {
3771                         return false;
3772                 }
3773                 # Does the article have a history?
3774                 $row = $dbw->selectField( array( 'page', 'revision' ),
3775                         'rev_id',
3776                         array( 'page_namespace' => $this->getNamespace(),
3777                                 'page_title' => $this->getDBkey(),
3778                                 'page_id=rev_page',
3779                                 'page_latest != rev_id'
3780                         ),
3781                         __METHOD__,
3782                         array( 'FOR UPDATE' )
3783                 );
3784                 # Return true if there was no history
3785                 return ( $row === false );
3786         }
3787
3788         /**
3789          * Checks if $this can be moved to a given Title
3790          * - Selects for update, so don't call it unless you mean business
3791          *
3792          * @deprecated since 1.25, use MovePage's methods instead
3793          * @param Title $nt The new title to check
3794          * @return bool
3795          */
3796         public function isValidMoveTarget( $nt ) {
3797                 # Is it an existing file?
3798                 if ( $nt->getNamespace() == NS_FILE ) {
3799                         $file = wfLocalFile( $nt );
3800                         $file->load( File::READ_LATEST );
3801                         if ( $file->exists() ) {
3802                                 wfDebug( __METHOD__ . ": file exists\n" );
3803                                 return false;
3804                         }
3805                 }
3806                 # Is it a redirect with no history?
3807                 if ( !$nt->isSingleRevRedirect() ) {
3808                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3809                         return false;
3810                 }
3811                 # Get the article text
3812                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3813                 if ( !is_object( $rev ) ) {
3814                         return false;
3815                 }
3816                 $content = $rev->getContent();
3817                 # Does the redirect point to the source?
3818                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3819                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3820
3821                 if ( $redirTitle ) {
3822                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3823                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3824                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3825                                 return false;
3826                         } else {
3827                                 return true;
3828                         }
3829                 } else {
3830                         # Fail safe (not a redirect after all. strange.)
3831                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3832                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3833                         return false;
3834                 }
3835         }
3836
3837         /**
3838          * Get categories to which this Title belongs and return an array of
3839          * categories' names.
3840          *
3841          * @return array Array of parents in the form:
3842          *        $parent => $currentarticle
3843          */
3844         public function getParentCategories() {
3845                 global $wgContLang;
3846
3847                 $data = array();
3848
3849                 $titleKey = $this->getArticleID();
3850
3851                 if ( $titleKey === 0 ) {
3852                         return $data;
3853                 }
3854
3855                 $dbr = wfGetDB( DB_SLAVE );
3856
3857                 $res = $dbr->select(
3858                         'categorylinks',
3859                         'cl_to',
3860                         array( 'cl_from' => $titleKey ),
3861                         __METHOD__
3862                 );
3863
3864                 if ( $res->numRows() > 0 ) {
3865                         foreach ( $res as $row ) {
3866                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3867                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3868                         }
3869                 }
3870                 return $data;
3871         }
3872
3873         /**
3874          * Get a tree of parent categories
3875          *
3876          * @param array $children Array with the children in the keys, to check for circular refs
3877          * @return array Tree of parent categories
3878          */
3879         public function getParentCategoryTree( $children = array() ) {
3880                 $stack = array();
3881                 $parents = $this->getParentCategories();
3882
3883                 if ( $parents ) {
3884                         foreach ( $parents as $parent => $current ) {
3885                                 if ( array_key_exists( $parent, $children ) ) {
3886                                         # Circular reference
3887                                         $stack[$parent] = array();
3888                                 } else {
3889                                         $nt = Title::newFromText( $parent );
3890                                         if ( $nt ) {
3891                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3892                                         }
3893                                 }
3894                         }
3895                 }
3896
3897                 return $stack;
3898         }
3899
3900         /**
3901          * Get an associative array for selecting this title from
3902          * the "page" table
3903          *
3904          * @return array Array suitable for the $where parameter of DB::select()
3905          */
3906         public function pageCond() {
3907                 if ( $this->mArticleID > 0 ) {
3908                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3909                         return array( 'page_id' => $this->mArticleID );
3910                 } else {
3911                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3912                 }
3913         }
3914
3915         /**
3916          * Get the revision ID of the previous revision
3917          *
3918          * @param int $revId Revision ID. Get the revision that was before this one.
3919          * @param int $flags Title::GAID_FOR_UPDATE
3920          * @return int|bool Old revision ID, or false if none exists
3921          */
3922         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3923                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3924                 $revId = $db->selectField( 'revision', 'rev_id',
3925                         array(
3926                                 'rev_page' => $this->getArticleID( $flags ),
3927                                 'rev_id < ' . intval( $revId )
3928                         ),
3929                         __METHOD__,
3930                         array( 'ORDER BY' => 'rev_id DESC' )
3931                 );
3932
3933                 if ( $revId === false ) {
3934                         return false;
3935                 } else {
3936                         return intval( $revId );
3937                 }
3938         }
3939
3940         /**
3941          * Get the revision ID of the next revision
3942          *
3943          * @param int $revId Revision ID. Get the revision that was after this one.
3944          * @param int $flags Title::GAID_FOR_UPDATE
3945          * @return int|bool Next revision ID, or false if none exists
3946          */
3947         public function getNextRevisionID( $revId, $flags = 0 ) {
3948                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3949                 $revId = $db->selectField( 'revision', 'rev_id',
3950                         array(
3951                                 'rev_page' => $this->getArticleID( $flags ),
3952                                 'rev_id > ' . intval( $revId )
3953                         ),
3954                         __METHOD__,
3955                         array( 'ORDER BY' => 'rev_id' )
3956                 );
3957
3958                 if ( $revId === false ) {
3959                         return false;
3960                 } else {
3961                         return intval( $revId );
3962                 }
3963         }
3964
3965         /**
3966          * Get the first revision of the page
3967          *
3968          * @param int $flags Title::GAID_FOR_UPDATE
3969          * @return Revision|null If page doesn't exist
3970          */
3971         public function getFirstRevision( $flags = 0 ) {
3972                 $pageId = $this->getArticleID( $flags );
3973                 if ( $pageId ) {
3974                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3975                         $row = $db->selectRow( 'revision', Revision::selectFields(),
3976                                 array( 'rev_page' => $pageId ),
3977                                 __METHOD__,
3978                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3979                         );
3980                         if ( $row ) {
3981                                 return new Revision( $row );
3982                         }
3983                 }
3984                 return null;
3985         }
3986
3987         /**
3988          * Get the oldest revision timestamp of this page
3989          *
3990          * @param int $flags Title::GAID_FOR_UPDATE
3991          * @return string MW timestamp
3992          */
3993         public function getEarliestRevTime( $flags = 0 ) {
3994                 $rev = $this->getFirstRevision( $flags );
3995                 return $rev ? $rev->getTimestamp() : null;
3996         }
3997
3998         /**
3999          * Check if this is a new page
4000          *
4001          * @return bool
4002          */
4003         public function isNewPage() {
4004                 $dbr = wfGetDB( DB_SLAVE );
4005                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4006         }
4007
4008         /**
4009          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4010          *
4011          * @return bool
4012          */
4013         public function isBigDeletion() {
4014                 global $wgDeleteRevisionsLimit;
4015
4016                 if ( !$wgDeleteRevisionsLimit ) {
4017                         return false;
4018                 }
4019
4020                 if ( $this->mIsBigDeletion === null ) {
4021                         $dbr = wfGetDB( DB_SLAVE );
4022
4023                         $revCount = $dbr->selectRowCount(
4024                                 'revision',
4025                                 '1',
4026                                 array( 'rev_page' => $this->getArticleID() ),
4027                                 __METHOD__,
4028                                 array( 'LIMIT' => $wgDeleteRevisionsLimit + 1 )
4029                         );
4030
4031                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4032                 }
4033
4034                 return $this->mIsBigDeletion;
4035         }
4036
4037         /**
4038          * Get the approximate revision count of this page.
4039          *
4040          * @return int
4041          */
4042         public function estimateRevisionCount() {
4043                 if ( !$this->exists() ) {
4044                         return 0;
4045                 }
4046
4047                 if ( $this->mEstimateRevisions === null ) {
4048                         $dbr = wfGetDB( DB_SLAVE );
4049                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4050                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4051                 }
4052
4053                 return $this->mEstimateRevisions;
4054         }
4055
4056         /**
4057          * Get the number of revisions between the given revision.
4058          * Used for diffs and other things that really need it.
4059          *
4060          * @param int|Revision $old Old revision or rev ID (first before range)
4061          * @param int|Revision $new New revision or rev ID (first after range)
4062          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4063          * @return int Number of revisions between these revisions.
4064          */
4065         public function countRevisionsBetween( $old, $new, $max = null ) {
4066                 if ( !( $old instanceof Revision ) ) {
4067                         $old = Revision::newFromTitle( $this, (int)$old );
4068                 }
4069                 if ( !( $new instanceof Revision ) ) {
4070                         $new = Revision::newFromTitle( $this, (int)$new );
4071                 }
4072                 if ( !$old || !$new ) {
4073                         return 0; // nothing to compare
4074                 }
4075                 $dbr = wfGetDB( DB_SLAVE );
4076                 $conds = array(
4077                         'rev_page' => $this->getArticleID(),
4078                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4079                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4080                 );
4081                 if ( $max !== null ) {
4082                         return $dbr->selectRowCount( 'revision', '1',
4083                                 $conds,
4084                                 __METHOD__,
4085                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4086                         );
4087                 } else {
4088                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4089                 }
4090         }
4091
4092         /**
4093          * Get the authors between the given revisions or revision IDs.
4094          * Used for diffs and other things that really need it.
4095          *
4096          * @since 1.23
4097          *
4098          * @param int|Revision $old Old revision or rev ID (first before range by default)
4099          * @param int|Revision $new New revision or rev ID (first after range by default)
4100          * @param int $limit Maximum number of authors
4101          * @param string|array $options (Optional): Single option, or an array of options:
4102          *     'include_old' Include $old in the range; $new is excluded.
4103          *     'include_new' Include $new in the range; $old is excluded.
4104          *     'include_both' Include both $old and $new in the range.
4105          *     Unknown option values are ignored.
4106          * @return array|null Names of revision authors in the range; null if not both revisions exist
4107          */
4108         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4109                 if ( !( $old instanceof Revision ) ) {
4110                         $old = Revision::newFromTitle( $this, (int)$old );
4111                 }
4112                 if ( !( $new instanceof Revision ) ) {
4113                         $new = Revision::newFromTitle( $this, (int)$new );
4114                 }
4115                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4116                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4117                 // in the sanity check below?
4118                 if ( !$old || !$new ) {
4119                         return null; // nothing to compare
4120                 }
4121                 $authors = array();
4122                 $old_cmp = '>';
4123                 $new_cmp = '<';
4124                 $options = (array)$options;
4125                 if ( in_array( 'include_old', $options ) ) {
4126                         $old_cmp = '>=';
4127                 }
4128                 if ( in_array( 'include_new', $options ) ) {
4129                         $new_cmp = '<=';
4130                 }
4131                 if ( in_array( 'include_both', $options ) ) {
4132                         $old_cmp = '>=';
4133                         $new_cmp = '<=';
4134                 }
4135                 // No DB query needed if $old and $new are the same or successive revisions:
4136                 if ( $old->getId() === $new->getId() ) {
4137                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4138                                 array() :
4139                                 array( $old->getUserText( Revision::RAW ) );
4140                 } elseif ( $old->getId() === $new->getParentId() ) {
4141                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4142                                 $authors[] = $old->getUserText( Revision::RAW );
4143                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4144                                         $authors[] = $new->getUserText( Revision::RAW );
4145                                 }
4146                         } elseif ( $old_cmp === '>=' ) {
4147                                 $authors[] = $old->getUserText( Revision::RAW );
4148                         } elseif ( $new_cmp === '<=' ) {
4149                                 $authors[] = $new->getUserText( Revision::RAW );
4150                         }
4151                         return $authors;
4152                 }
4153                 $dbr = wfGetDB( DB_SLAVE );
4154                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4155                         array(
4156                                 'rev_page' => $this->getArticleID(),
4157                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4158                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4159                         ), __METHOD__,
4160                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4161                 );
4162                 foreach ( $res as $row ) {
4163                         $authors[] = $row->rev_user_text;
4164                 }
4165                 return $authors;
4166         }
4167
4168         /**
4169          * Get the number of authors between the given revisions or revision IDs.
4170          * Used for diffs and other things that really need it.
4171          *
4172          * @param int|Revision $old Old revision or rev ID (first before range by default)
4173          * @param int|Revision $new New revision or rev ID (first after range by default)
4174          * @param int $limit Maximum number of authors
4175          * @param string|array $options (Optional): Single option, or an array of options:
4176          *     'include_old' Include $old in the range; $new is excluded.
4177          *     'include_new' Include $new in the range; $old is excluded.
4178          *     'include_both' Include both $old and $new in the range.
4179          *     Unknown option values are ignored.
4180          * @return int Number of revision authors in the range; zero if not both revisions exist
4181          */
4182         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4183                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4184                 return $authors ? count( $authors ) : 0;
4185         }
4186
4187         /**
4188          * Compare with another title.
4189          *
4190          * @param Title $title
4191          * @return bool
4192          */
4193         public function equals( Title $title ) {
4194                 // Note: === is necessary for proper matching of number-like titles.
4195                 return $this->getInterwiki() === $title->getInterwiki()
4196                         && $this->getNamespace() == $title->getNamespace()
4197                         && $this->getDBkey() === $title->getDBkey();
4198         }
4199
4200         /**
4201          * Check if this title is a subpage of another title
4202          *
4203          * @param Title $title
4204          * @return bool
4205          */
4206         public function isSubpageOf( Title $title ) {
4207                 return $this->getInterwiki() === $title->getInterwiki()
4208                         && $this->getNamespace() == $title->getNamespace()
4209                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4210         }
4211
4212         /**
4213          * Check if page exists.  For historical reasons, this function simply
4214          * checks for the existence of the title in the page table, and will
4215          * thus return false for interwiki links, special pages and the like.
4216          * If you want to know if a title can be meaningfully viewed, you should
4217          * probably call the isKnown() method instead.
4218          *
4219          * @return bool
4220          */
4221         public function exists() {
4222                 $exists = $this->getArticleID() != 0;
4223                 Hooks::run( 'TitleExists', array( $this, &$exists ) );
4224                 return $exists;
4225         }
4226
4227         /**
4228          * Should links to this title be shown as potentially viewable (i.e. as
4229          * "bluelinks"), even if there's no record by this title in the page
4230          * table?
4231          *
4232          * This function is semi-deprecated for public use, as well as somewhat
4233          * misleadingly named.  You probably just want to call isKnown(), which
4234          * calls this function internally.
4235          *
4236          * (ISSUE: Most of these checks are cheap, but the file existence check
4237          * can potentially be quite expensive.  Including it here fixes a lot of
4238          * existing code, but we might want to add an optional parameter to skip
4239          * it and any other expensive checks.)
4240          *
4241          * @return bool
4242          */
4243         public function isAlwaysKnown() {
4244                 $isKnown = null;
4245
4246                 /**
4247                  * Allows overriding default behavior for determining if a page exists.
4248                  * If $isKnown is kept as null, regular checks happen. If it's
4249                  * a boolean, this value is returned by the isKnown method.
4250                  *
4251                  * @since 1.20
4252                  *
4253                  * @param Title $title
4254                  * @param bool|null $isKnown
4255                  */
4256                 Hooks::run( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4257
4258                 if ( !is_null( $isKnown ) ) {
4259                         return $isKnown;
4260                 }
4261
4262                 if ( $this->isExternal() ) {
4263                         return true;  // any interwiki link might be viewable, for all we know
4264                 }
4265
4266                 switch ( $this->mNamespace ) {
4267                         case NS_MEDIA:
4268                         case NS_FILE:
4269                                 // file exists, possibly in a foreign repo
4270                                 return (bool)wfFindFile( $this );
4271                         case NS_SPECIAL:
4272                                 // valid special page
4273                                 return SpecialPageFactory::exists( $this->getDBkey() );
4274                         case NS_MAIN:
4275                                 // selflink, possibly with fragment
4276                                 return $this->mDbkeyform == '';
4277                         case NS_MEDIAWIKI:
4278                                 // known system message
4279                                 return $this->hasSourceText() !== false;
4280                         default:
4281                                 return false;
4282                 }
4283         }
4284
4285         /**
4286          * Does this title refer to a page that can (or might) be meaningfully
4287          * viewed?  In particular, this function may be used to determine if
4288          * links to the title should be rendered as "bluelinks" (as opposed to
4289          * "redlinks" to non-existent pages).
4290          * Adding something else to this function will cause inconsistency
4291          * since LinkHolderArray calls isAlwaysKnown() and does its own
4292          * page existence check.
4293          *
4294          * @return bool
4295          */
4296         public function isKnown() {
4297                 return $this->isAlwaysKnown() || $this->exists();
4298         }
4299
4300         /**
4301          * Does this page have source text?
4302          *
4303          * @return bool
4304          */
4305         public function hasSourceText() {
4306                 if ( $this->exists() ) {
4307                         return true;
4308                 }
4309
4310                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4311                         // If the page doesn't exist but is a known system message, default
4312                         // message content will be displayed, same for language subpages-
4313                         // Use always content language to avoid loading hundreds of languages
4314                         // to get the link color.
4315                         global $wgContLang;
4316                         list( $name, ) = MessageCache::singleton()->figureMessage(
4317                                 $wgContLang->lcfirst( $this->getText() )
4318                         );
4319                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4320                         return $message->exists();
4321                 }
4322
4323                 return false;
4324         }
4325
4326         /**
4327          * Get the default message text or false if the message doesn't exist
4328          *
4329          * @return string|bool
4330          */
4331         public function getDefaultMessageText() {
4332                 global $wgContLang;
4333
4334                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4335                         return false;
4336                 }
4337
4338                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4339                         $wgContLang->lcfirst( $this->getText() )
4340                 );
4341                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4342
4343                 if ( $message->exists() ) {
4344                         return $message->plain();
4345                 } else {
4346                         return false;
4347                 }
4348         }
4349
4350         /**
4351          * Updates page_touched for this page; called from LinksUpdate.php
4352          *
4353          * @return bool True if the update succeeded
4354          */
4355         public function invalidateCache() {
4356                 if ( wfReadOnly() ) {
4357                         return false;
4358                 }
4359
4360                 if ( $this->mArticleID === 0 ) {
4361                         return true; // avoid gap locking if we know it's not there
4362                 }
4363
4364                 $method = __METHOD__;
4365                 $dbw = wfGetDB( DB_MASTER );
4366                 $conds = $this->pageCond();
4367                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method ) {
4368                         $dbw->update(
4369                                 'page',
4370                                 array( 'page_touched' => $dbw->timestamp() ),
4371                                 $conds,
4372                                 $method
4373                         );
4374                 } );
4375
4376                 return true;
4377         }
4378
4379         /**
4380          * Update page_touched timestamps and send squid purge messages for
4381          * pages linking to this title. May be sent to the job queue depending
4382          * on the number of links. Typically called on create and delete.
4383          */
4384         public function touchLinks() {
4385                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4386                 $u->doUpdate();
4387
4388                 if ( $this->getNamespace() == NS_CATEGORY ) {
4389                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4390                         $u->doUpdate();
4391                 }
4392         }
4393
4394         /**
4395          * Get the last touched timestamp
4396          *
4397          * @param DatabaseBase $db Optional db
4398          * @return string Last-touched timestamp
4399          */
4400         public function getTouched( $db = null ) {
4401                 if ( $db === null ) {
4402                         $db = wfGetDB( DB_SLAVE );
4403                 }
4404                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4405                 return $touched;
4406         }
4407
4408         /**
4409          * Get the timestamp when this page was updated since the user last saw it.
4410          *
4411          * @param User $user
4412          * @return string|null
4413          */
4414         public function getNotificationTimestamp( $user = null ) {
4415                 global $wgUser, $wgShowUpdatedMarker;
4416                 // Assume current user if none given
4417                 if ( !$user ) {
4418                         $user = $wgUser;
4419                 }
4420                 // Check cache first
4421                 $uid = $user->getId();
4422                 // avoid isset here, as it'll return false for null entries
4423                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4424                         return $this->mNotificationTimestamp[$uid];
4425                 }
4426                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4427                         $this->mNotificationTimestamp[$uid] = false;
4428                         return $this->mNotificationTimestamp[$uid];
4429                 }
4430                 // Don't cache too much!
4431                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4432                         $this->mNotificationTimestamp = array();
4433                 }
4434                 $dbr = wfGetDB( DB_SLAVE );
4435                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4436                         'wl_notificationtimestamp',
4437                         array(
4438                                 'wl_user' => $user->getId(),
4439                                 'wl_namespace' => $this->getNamespace(),
4440                                 'wl_title' => $this->getDBkey(),
4441                         ),
4442                         __METHOD__
4443                 );
4444                 return $this->mNotificationTimestamp[$uid];
4445         }
4446
4447         /**
4448          * Generate strings used for xml 'id' names in monobook tabs
4449          *
4450          * @param string $prepend Defaults to 'nstab-'
4451          * @return string XML 'id' name
4452          */
4453         public function getNamespaceKey( $prepend = 'nstab-' ) {
4454                 global $wgContLang;
4455                 // Gets the subject namespace if this title
4456                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4457                 // Checks if canonical namespace name exists for namespace
4458                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4459                         // Uses canonical namespace name
4460                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4461                 } else {
4462                         // Uses text of namespace
4463                         $namespaceKey = $this->getSubjectNsText();
4464                 }
4465                 // Makes namespace key lowercase
4466                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4467                 // Uses main
4468                 if ( $namespaceKey == '' ) {
4469                         $namespaceKey = 'main';
4470                 }
4471                 // Changes file to image for backwards compatibility
4472                 if ( $namespaceKey == 'file' ) {
4473                         $namespaceKey = 'image';
4474                 }
4475                 return $prepend . $namespaceKey;
4476         }
4477
4478         /**
4479          * Get all extant redirects to this Title
4480          *
4481          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4482          * @return Title[] Array of Title redirects to this title
4483          */
4484         public function getRedirectsHere( $ns = null ) {
4485                 $redirs = array();
4486
4487                 $dbr = wfGetDB( DB_SLAVE );
4488                 $where = array(
4489                         'rd_namespace' => $this->getNamespace(),
4490                         'rd_title' => $this->getDBkey(),
4491                         'rd_from = page_id'
4492                 );
4493                 if ( $this->isExternal() ) {
4494                         $where['rd_interwiki'] = $this->getInterwiki();
4495                 } else {
4496                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4497                 }
4498                 if ( !is_null( $ns ) ) {
4499                         $where['page_namespace'] = $ns;
4500                 }
4501
4502                 $res = $dbr->select(
4503                         array( 'redirect', 'page' ),
4504                         array( 'page_namespace', 'page_title' ),
4505                         $where,
4506                         __METHOD__
4507                 );
4508
4509                 foreach ( $res as $row ) {
4510                         $redirs[] = self::newFromRow( $row );
4511                 }
4512                 return $redirs;
4513         }
4514
4515         /**
4516          * Check if this Title is a valid redirect target
4517          *
4518          * @return bool
4519          */
4520         public function isValidRedirectTarget() {
4521                 global $wgInvalidRedirectTargets;
4522
4523                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4524                 if ( $this->isSpecial( 'Userlogout' ) ) {
4525                         return false;
4526                 }
4527
4528                 foreach ( $wgInvalidRedirectTargets as $target ) {
4529                         if ( $this->isSpecial( $target ) ) {
4530                                 return false;
4531                         }
4532                 }
4533
4534                 return true;
4535         }
4536
4537         /**
4538          * Get a backlink cache object
4539          *
4540          * @return BacklinkCache
4541          */
4542         public function getBacklinkCache() {
4543                 return BacklinkCache::get( $this );
4544         }
4545
4546         /**
4547          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4548          *
4549          * @return bool
4550          */
4551         public function canUseNoindex() {
4552                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4553
4554                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4555                         ? $wgContentNamespaces
4556                         : $wgExemptFromUserRobotsControl;
4557
4558                 return !in_array( $this->mNamespace, $bannedNamespaces );
4559
4560         }
4561
4562         /**
4563          * Returns the raw sort key to be used for categories, with the specified
4564          * prefix.  This will be fed to Collation::getSortKey() to get a
4565          * binary sortkey that can be used for actual sorting.
4566          *
4567          * @param string $prefix The prefix to be used, specified using
4568          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4569          *   prefix.
4570          * @return string
4571          */
4572         public function getCategorySortkey( $prefix = '' ) {
4573                 $unprefixed = $this->getText();
4574
4575                 // Anything that uses this hook should only depend
4576                 // on the Title object passed in, and should probably
4577                 // tell the users to run updateCollations.php --force
4578                 // in order to re-sort existing category relations.
4579                 Hooks::run( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4580                 if ( $prefix !== '' ) {
4581                         # Separate with a line feed, so the unprefixed part is only used as
4582                         # a tiebreaker when two pages have the exact same prefix.
4583                         # In UCA, tab is the only character that can sort above LF
4584                         # so we strip both of them from the original prefix.
4585                         $prefix = strtr( $prefix, "\n\t", '  ' );
4586                         return "$prefix\n$unprefixed";
4587                 }
4588                 return $unprefixed;
4589         }
4590
4591         /**
4592          * Get the language in which the content of this page is written in
4593          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4594          * e.g. $wgLang (such as special pages, which are in the user language).
4595          *
4596          * @since 1.18
4597          * @return Language
4598          */
4599         public function getPageLanguage() {
4600                 global $wgLang, $wgLanguageCode;
4601                 if ( $this->isSpecialPage() ) {
4602                         // special pages are in the user language
4603                         return $wgLang;
4604                 }
4605
4606                 // Checking if DB language is set
4607                 if ( $this->mDbPageLanguage ) {
4608                         return wfGetLangObj( $this->mDbPageLanguage );
4609                 }
4610
4611                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4612                         // Note that this may depend on user settings, so the cache should
4613                         // be only per-request.
4614                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4615                         // content to determine the page language!
4616                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4617                         // tests.
4618                         $contentHandler = ContentHandler::getForTitle( $this );
4619                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4620                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4621                 } else {
4622                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4623                 }
4624
4625                 return $langObj;
4626         }
4627
4628         /**
4629          * Get the language in which the content of this page is written when
4630          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4631          * e.g. $wgLang (such as special pages, which are in the user language).
4632          *
4633          * @since 1.20
4634          * @return Language
4635          */
4636         public function getPageViewLanguage() {
4637                 global $wgLang;
4638
4639                 if ( $this->isSpecialPage() ) {
4640                         // If the user chooses a variant, the content is actually
4641                         // in a language whose code is the variant code.
4642                         $variant = $wgLang->getPreferredVariant();
4643                         if ( $wgLang->getCode() !== $variant ) {
4644                                 return Language::factory( $variant );
4645                         }
4646
4647                         return $wgLang;
4648                 }
4649
4650                 // @note Can't be cached persistently, depends on user settings.
4651                 // @note ContentHandler::getPageViewLanguage() may need to load the
4652                 //   content to determine the page language!
4653                 $contentHandler = ContentHandler::getForTitle( $this );
4654                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4655                 return $pageLang;
4656         }
4657
4658         /**
4659          * Get a list of rendered edit notices for this page.
4660          *
4661          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4662          * they will already be wrapped in paragraphs.
4663          *
4664          * @since 1.21
4665          * @param int $oldid Revision ID that's being edited
4666          * @return array
4667          */
4668         public function getEditNotices( $oldid = 0 ) {
4669                 $notices = array();
4670
4671                 // Optional notice for the entire namespace
4672                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4673                 $msg = wfMessage( $editnotice_ns );
4674                 if ( $msg->exists() ) {
4675                         $html = $msg->parseAsBlock();
4676                         // Edit notices may have complex logic, but output nothing (T91715)
4677                         if ( trim( $html ) !== '' ) {
4678                                 $notices[$editnotice_ns] = Html::rawElement(
4679                                         'div',
4680                                         array( 'class' => array(
4681                                                 'mw-editnotice',
4682                                                 'mw-editnotice-namespace',
4683                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4684                                         ) ),
4685                                         $html
4686                                 );
4687                         }
4688                 }
4689
4690                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4691                         // Optional notice for page itself and any parent page
4692                         $parts = explode( '/', $this->getDBkey() );
4693                         $editnotice_base = $editnotice_ns;
4694                         while ( count( $parts ) > 0 ) {
4695                                 $editnotice_base .= '-' . array_shift( $parts );
4696                                 $msg = wfMessage( $editnotice_base );
4697                                 if ( $msg->exists() ) {
4698                                         $html = $msg->parseAsBlock();
4699                                         if ( trim( $html ) !== '' ) {
4700                                                 $notices[$editnotice_base] = Html::rawElement(
4701                                                         'div',
4702                                                         array( 'class' => array(
4703                                                                 'mw-editnotice',
4704                                                                 'mw-editnotice-base',
4705                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4706                                                         ) ),
4707                                                         $html
4708                                                 );
4709                                         }
4710                                 }
4711                         }
4712                 } else {
4713                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4714                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4715                         $msg = wfMessage( $editnoticeText );
4716                         if ( $msg->exists() ) {
4717                                 $html = $msg->parseAsBlock();
4718                                 if ( trim( $html ) !== '' ) {
4719                                         $notices[$editnoticeText] = Html::rawElement(
4720                                                 'div',
4721                                                 array( 'class' => array(
4722                                                         'mw-editnotice',
4723                                                         'mw-editnotice-page',
4724                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4725                                                 ) ),
4726                                                 $html
4727                                         );
4728                                 }
4729                         }
4730                 }
4731
4732                 Hooks::run( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4733                 return $notices;
4734         }
4735 }