includes/Title.php

   1 <?php
   2 /**
   3  * Representation of a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  31  *       and does not rely on global state or the database.
  32  *
  33  * @internal documentation reviewed 15 Mar 2010
  34  */
  35 class Title {
  36         /** @var MapCacheLRU */
  37         static private $titleCache = null;
  38
  39         /**
  40          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  41          * commonly used titles. On a batch operation this can become a memory leak
  42          * if not bounded. After hitting this many titles reset the cache.
  43          */
  44         const CACHE_MAX = 1000;
  45
  46         /**
  47          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  48          * to use the master DB
  49          */
  50         const GAID_FOR_UPDATE = 1;
  51
  52         /**
  53          * @name Private member variables
  54          * Please use the accessor functions instead.
  55          * @private
  56          */
  57         // @{
  58
  59         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  60         var $mUrlform = '';               // /< URL-encoded form of the main part
  61         var $mDbkeyform = '';             // /< Main part with underscores
  62         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  63         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  64         var $mInterwiki = '';             // /< Interwiki prefix
  65         var $mFragment = '';              // /< Title fragment (i.e. the bit after the #)
  66         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  67         var $mLatestID = false;           // /< ID of most recent revision
  68         var $mContentModel = false;       // /< ID of the page's content model, i.e. one of the CONTENT_MODEL_XXX constants
  69         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  70         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  71         var $mOldRestrictions = false;
  72         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  73         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  74         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  75         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  76         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  77         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  78         var $mPrefixedText = null;        ///< Text form including namespace/interwiki, initialised on demand
  79         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  80         # Don't change the following default, NS_MAIN is hardcoded in several
  81         # places.  See bug 696.
  82         # Zero except in {{transclusion}} tags
  83         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  84         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  85         var $mLength = -1;                // /< The page length, 0 for special pages
  86         var $mRedirect = null;            // /< Is the article at this title a redirect?
  87         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  88         var $mHasSubpage;                 // /< Whether a page has any subpages
  89         private $mPageLanguage = false;   // /< The (string) language code of the page's language and content code.
  90         private $mTitleValue = null;      // /< A corresponding TitleValue object
  91         // @}
  92
  93         /**
  94          * B/C kludge: provide a TitleParser for use by Title.
  95          * Ideally, Title would have no methods that need this.
  96          * Avoid usage of this singleton by using TitleValue
  97          * and the associated services when possible.
  98          *
  99          * @return TitleParser
 100          */
 101         private static function getTitleParser() {
 102                 global $wgContLang, $wgLocalInterwikis;
 103
 104                 static $titleCodec = null;
 105                 static $titleCodecFingerprint = null;
 106
 107                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 108                 // make sure we are using the right one. To detect changes over the course
 109                 // of a request, we remember a fingerprint of the config used to create the
 110                 // codec singleton, and re-create it if the fingerprint doesn't match.
 111                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . join( '+', $wgLocalInterwikis );
 112
 113                 if ( $fingerprint !== $titleCodecFingerprint ) {
 114                         $titleCodec = null;
 115                 }
 116
 117                 if ( !$titleCodec ) {
 118                         $titleCodec = new MediaWikiTitleCodec( $wgContLang, GenderCache::singleton(), $wgLocalInterwikis );
 119                         $titleCodecFingerprint = $fingerprint;
 120                 }
 121
 122                 return $titleCodec;
 123         }
 124
 125         /**
 126          * B/C kludge: provide a TitleParser for use by Title.
 127          * Ideally, Title would have no methods that need this.
 128          * Avoid usage of this singleton by using TitleValue
 129          * and the associated services when possible.
 130          *
 131          * @return TitleFormatter
 132          */
 133         private static function getTitleFormatter() {
 134                 //NOTE: we know that getTitleParser() returns a MediaWikiTitleCodec,
 135                 //      which implements TitleFormatter.
 136                 return self::getTitleParser();
 137         }
 138
 139         /**
 140          * Constructor
 141          */
 142         /*protected*/ function __construct() { }
 143
 144         /**
 145          * Create a new Title from a prefixed DB key
 146          *
 147          * @param string $key the database key, which has underscores
 148          *      instead of spaces, possibly including namespace and
 149          *      interwiki prefixes
 150          * @return Title, or NULL on an error
 151          */
 152         public static function newFromDBkey( $key ) {
 153                 $t = new Title();
 154                 $t->mDbkeyform = $key;
 155                 if ( $t->secureAndSplit() ) {
 156                         return $t;
 157                 } else {
 158                         return null;
 159                 }
 160         }
 161
 162         /**
 163          * Create a new Title from a TitleValue
 164          *
 165          * @param TitleValue $titleValue, assumed to be safe.
 166          *
 167          * @return Title
 168          */
 169         public static function newFromTitleValue( TitleValue $titleValue ) {
 170                 return self::makeTitle(
 171                         $titleValue->getNamespace(),
 172                         $titleValue->getText(),
 173                         $titleValue->getFragment() );
 174         }
 175
 176         /**
 177          * Create a new Title from text, such as what one would find in a link. De-
 178          * codes any HTML entities in the text.
 179          *
 180          * @param string $text the link text; spaces, prefixes, and an
 181          *   initial ':' indicating the main namespace are accepted.
 182          * @param int $defaultNamespace the namespace to use if none is specified
 183          *   by a prefix.  If you want to force a specific namespace even if
 184          *   $text might begin with a namespace prefix, use makeTitle() or
 185          *   makeTitleSafe().
 186          * @throws MWException
 187          * @return Title|null - Title or null on an error.
 188          */
 189         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 190                 if ( is_object( $text ) ) {
 191                         throw new MWException( 'Title::newFromText given an object' );
 192                 }
 193
 194                 $cache = self::getTitleCache();
 195
 196                 /**
 197                  * Wiki pages often contain multiple links to the same page.
 198                  * Title normalization and parsing can become expensive on
 199                  * pages with many links, so we can save a little time by
 200                  * caching them.
 201                  *
 202                  * In theory these are value objects and won't get changed...
 203                  */
 204                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 205                         return $cache->get( $text );
 206                 }
 207
 208                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 209                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 210
 211                 $t = new Title();
 212                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 213                 $t->mDefaultNamespace = intval( $defaultNamespace );
 214
 215                 if ( $t->secureAndSplit() ) {
 216                         if ( $defaultNamespace == NS_MAIN ) {
 217                                 $cache->set( $text, $t );
 218                         }
 219                         return $t;
 220                 } else {
 221                         $ret = null;
 222                         return $ret;
 223                 }
 224         }
 225
 226         /**
 227          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 228          *
 229          * Example of wrong and broken code:
 230          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 231          *
 232          * Example of right code:
 233          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 234          *
 235          * Create a new Title from URL-encoded text. Ensures that
 236          * the given title's length does not exceed the maximum.
 237          *
 238          * @param string $url the title, as might be taken from a URL
 239          * @return Title the new object, or NULL on an error
 240          */
 241         public static function newFromURL( $url ) {
 242                 $t = new Title();
 243
 244                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 245                 # but some URLs used it as a space replacement and they still come
 246                 # from some external search tools.
 247                 if ( strpos( self::legalChars(), '+' ) === false ) {
 248                         $url = str_replace( '+', ' ', $url );
 249                 }
 250
 251                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 252                 if ( $t->secureAndSplit() ) {
 253                         return $t;
 254                 } else {
 255                         return null;
 256                 }
 257         }
 258
 259         /**
 260          * @return MapCacheLRU
 261          */
 262         private static function getTitleCache() {
 263                 if ( self::$titleCache == null ) {
 264                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 265                 }
 266                 return self::$titleCache;
 267         }
 268
 269         /**
 270          * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 271          * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
 272          *
 273          * @return array
 274          */
 275         protected static function getSelectFields() {
 276                 global $wgContentHandlerUseDB;
 277
 278                 $fields = array(
 279                         'page_namespace', 'page_title', 'page_id',
 280                         'page_len', 'page_is_redirect', 'page_latest',
 281                 );
 282
 283                 if ( $wgContentHandlerUseDB ) {
 284                         $fields[] = 'page_content_model';
 285                 }
 286
 287                 return $fields;
 288         }
 289
 290         /**
 291          * Create a new Title from an article ID
 292          *
 293          * @param int $id the page_id corresponding to the Title to create
 294          * @param int $flags use Title::GAID_FOR_UPDATE to use master
 295          * @return Title|null the new object, or NULL on an error
 296          */
 297         public static function newFromID( $id, $flags = 0 ) {
 298                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 299                 $row = $db->selectRow(
 300                         'page',
 301                         self::getSelectFields(),
 302                         array( 'page_id' => $id ),
 303                         __METHOD__
 304                 );
 305                 if ( $row !== false ) {
 306                         $title = Title::newFromRow( $row );
 307                 } else {
 308                         $title = null;
 309                 }
 310                 return $title;
 311         }
 312
 313         /**
 314          * Make an array of titles from an array of IDs
 315          *
 316          * @param array $ids of Int Array of IDs
 317          * @return Array of Titles
 318          */
 319         public static function newFromIDs( $ids ) {
 320                 if ( !count( $ids ) ) {
 321                         return array();
 322                 }
 323                 $dbr = wfGetDB( DB_SLAVE );
 324
 325                 $res = $dbr->select(
 326                         'page',
 327                         self::getSelectFields(),
 328                         array( 'page_id' => $ids ),
 329                         __METHOD__
 330                 );
 331
 332                 $titles = array();
 333                 foreach ( $res as $row ) {
 334                         $titles[] = Title::newFromRow( $row );
 335                 }
 336                 return $titles;
 337         }
 338
 339         /**
 340          * Make a Title object from a DB row
 341          *
 342          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 343          * @return Title corresponding Title
 344          */
 345         public static function newFromRow( $row ) {
 346                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 347                 $t->loadFromRow( $row );
 348                 return $t;
 349         }
 350
 351         /**
 352          * Load Title object fields from a DB row.
 353          * If false is given, the title will be treated as non-existing.
 354          *
 355          * @param $row stdClass|bool database row
 356          */
 357         public function loadFromRow( $row ) {
 358                 if ( $row ) { // page found
 359                         if ( isset( $row->page_id ) ) {
 360                                 $this->mArticleID = (int)$row->page_id;
 361                         }
 362                         if ( isset( $row->page_len ) ) {
 363                                 $this->mLength = (int)$row->page_len;
 364                         }
 365                         if ( isset( $row->page_is_redirect ) ) {
 366                                 $this->mRedirect = (bool)$row->page_is_redirect;
 367                         }
 368                         if ( isset( $row->page_latest ) ) {
 369                                 $this->mLatestID = (int)$row->page_latest;
 370                         }
 371                         if ( isset( $row->page_content_model ) ) {
 372                                 $this->mContentModel = strval( $row->page_content_model );
 373                         } else {
 374                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 375                         }
 376                 } else { // page not found
 377                         $this->mArticleID = 0;
 378                         $this->mLength = 0;
 379                         $this->mRedirect = false;
 380                         $this->mLatestID = 0;
 381                         $this->mContentModel = false; # initialized lazily in getContentModel()
 382                 }
 383         }
 384
 385         /**
 386          * Create a new Title from a namespace index and a DB key.
 387          * It's assumed that $ns and $title are *valid*, for instance when
 388          * they came directly from the database or a special page name.
 389          * For convenience, spaces are converted to underscores so that
 390          * eg user_text fields can be used directly.
 391          *
 392          * @param int $ns the namespace of the article
 393          * @param string $title the unprefixed database key form
 394          * @param string $fragment the link fragment (after the "#")
 395          * @param string $interwiki the interwiki prefix
 396          * @return Title the new object
 397          */
 398         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 399                 $t = new Title();
 400                 $t->mInterwiki = $interwiki;
 401                 $t->mFragment = $fragment;
 402                 $t->mNamespace = $ns = intval( $ns );
 403                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 404                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 405                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 406                 $t->mTextform = str_replace( '_', ' ', $title );
 407                 $t->mContentModel = false; # initialized lazily in getContentModel()
 408                 return $t;
 409         }
 410
 411         /**
 412          * Create a new Title from a namespace index and a DB key.
 413          * The parameters will be checked for validity, which is a bit slower
 414          * than makeTitle() but safer for user-provided data.
 415          *
 416          * @param int $ns the namespace of the article
 417          * @param string $title database key form
 418          * @param string $fragment the link fragment (after the "#")
 419          * @param string $interwiki interwiki prefix
 420          * @return Title the new object, or NULL on an error
 421          */
 422         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 423                 if ( !MWNamespace::exists( $ns ) ) {
 424                         return null;
 425                 }
 426
 427                 $t = new Title();
 428                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 429                 if ( $t->secureAndSplit() ) {
 430                         return $t;
 431                 } else {
 432                         return null;
 433                 }
 434         }
 435
 436         /**
 437          * Create a new Title for the Main Page
 438          *
 439          * @return Title the new object
 440          */
 441         public static function newMainPage() {
 442                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 443                 // Don't give fatal errors if the message is broken
 444                 if ( !$title ) {
 445                         $title = Title::newFromText( 'Main Page' );
 446                 }
 447                 return $title;
 448         }
 449
 450         /**
 451          * Extract a redirect destination from a string and return the
 452          * Title, or null if the text doesn't contain a valid redirect
 453          * This will only return the very next target, useful for
 454          * the redirect table and other checks that don't need full recursion
 455          *
 456          * @param string $text Text with possible redirect
 457          * @return Title: The corresponding Title
 458          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 459          */
 460         public static function newFromRedirect( $text ) {
 461                 ContentHandler::deprecated( __METHOD__, '1.21' );
 462
 463                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 464                 return $content->getRedirectTarget();
 465         }
 466
 467         /**
 468          * Extract a redirect destination from a string and return the
 469          * Title, or null if the text doesn't contain a valid redirect
 470          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 471          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 472          *
 473          * @param string $text Text with possible redirect
 474          * @return Title
 475          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 476          */
 477         public static function newFromRedirectRecurse( $text ) {
 478                 ContentHandler::deprecated( __METHOD__, '1.21' );
 479
 480                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 481                 return $content->getUltimateRedirectTarget();
 482         }
 483
 484         /**
 485          * Extract a redirect destination from a string and return an
 486          * array of Titles, or null if the text doesn't contain a valid redirect
 487          * The last element in the array is the final destination after all redirects
 488          * have been resolved (up to $wgMaxRedirects times)
 489          *
 490          * @param string $text Text with possible redirect
 491          * @return Array of Titles, with the destination last
 492          * @deprecated since 1.21, use Content::getRedirectChain instead.
 493          */
 494         public static function newFromRedirectArray( $text ) {
 495                 ContentHandler::deprecated( __METHOD__, '1.21' );
 496
 497                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 498                 return $content->getRedirectChain();
 499         }
 500
 501         /**
 502          * Get the prefixed DB key associated with an ID
 503          *
 504          * @param int $id the page_id of the article
 505          * @return Title an object representing the article, or NULL if no such article was found
 506          */
 507         public static function nameOf( $id ) {
 508                 $dbr = wfGetDB( DB_SLAVE );
 509
 510                 $s = $dbr->selectRow(
 511                         'page',
 512                         array( 'page_namespace', 'page_title' ),
 513                         array( 'page_id' => $id ),
 514                         __METHOD__
 515                 );
 516                 if ( $s === false ) {
 517                         return null;
 518                 }
 519
 520                 $n = self::makeName( $s->page_namespace, $s->page_title );
 521                 return $n;
 522         }
 523
 524         /**
 525          * Get a regex character class describing the legal characters in a link
 526          *
 527          * @return String the list of characters, not delimited
 528          */
 529         public static function legalChars() {
 530                 global $wgLegalTitleChars;
 531                 return $wgLegalTitleChars;
 532         }
 533
 534         /**
 535          * Returns a simple regex that will match on characters and sequences invalid in titles.
 536          * Note that this doesn't pick up many things that could be wrong with titles, but that
 537          * replacing this regex with something valid will make many titles valid.
 538          *
 539          * @todo: move this into MediaWikiTitleCodec
 540          *
 541          * @return String regex string
 542          */
 543         static function getTitleInvalidRegex() {
 544                 static $rxTc = false;
 545                 if ( !$rxTc ) {
 546                         # Matching titles will be held as illegal.
 547                         $rxTc = '/' .
 548                                 # Any character not allowed is forbidden...
 549                                 '[^' . self::legalChars() . ']' .
 550                                 # URL percent encoding sequences interfere with the ability
 551                                 # to round-trip titles -- you can't link to them consistently.
 552                                 '|%[0-9A-Fa-f]{2}' .
 553                                 # XML/HTML character references produce similar issues.
 554                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 555                                 '|&#[0-9]+;' .
 556                                 '|&#x[0-9A-Fa-f]+;' .
 557                                 '/S';
 558                 }
 559
 560                 return $rxTc;
 561         }
 562
 563         /**
 564          * Utility method for converting a character sequence from bytes to Unicode.
 565          *
 566          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 567          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 568          *
 569          * @param string $byteClass
 570          * @return string
 571          */
 572         public static function convertByteClassToUnicodeClass( $byteClass ) {
 573                 $length = strlen( $byteClass );
 574                 // Input token queue
 575                 $x0 = $x1 = $x2 = '';
 576                 // Decoded queue
 577                 $d0 = $d1 = $d2 = '';
 578                 // Decoded integer codepoints
 579                 $ord0 = $ord1 = $ord2 = 0;
 580                 // Re-encoded queue
 581                 $r0 = $r1 = $r2 = '';
 582                 // Output
 583                 $out = '';
 584                 // Flags
 585                 $allowUnicode = false;
 586                 for ( $pos = 0; $pos < $length; $pos++ ) {
 587                         // Shift the queues down
 588                         $x2 = $x1;
 589                         $x1 = $x0;
 590                         $d2 = $d1;
 591                         $d1 = $d0;
 592                         $ord2 = $ord1;
 593                         $ord1 = $ord0;
 594                         $r2 = $r1;
 595                         $r1 = $r0;
 596                         // Load the current input token and decoded values
 597                         $inChar = $byteClass[$pos];
 598                         if ( $inChar == '\\' ) {
 599                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 600                                         $x0 = $inChar . $m[0];
 601                                         $d0 = chr( hexdec( $m[1] ) );
 602                                         $pos += strlen( $m[0] );
 603                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 604                                         $x0 = $inChar . $m[0];
 605                                         $d0 = chr( octdec( $m[0] ) );
 606                                         $pos += strlen( $m[0] );
 607                                 } elseif ( $pos + 1 >= $length ) {
 608                                         $x0 = $d0 = '\\';
 609                                 } else {
 610                                         $d0 = $byteClass[$pos + 1];
 611                                         $x0 = $inChar . $d0;
 612                                         $pos += 1;
 613                                 }
 614                         } else {
 615                                 $x0 = $d0 = $inChar;
 616                         }
 617                         $ord0 = ord( $d0 );
 618                         // Load the current re-encoded value
 619                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 620                                 $r0 = sprintf( '\x%02x', $ord0 );
 621                         } elseif ( $ord0 >= 0x80 ) {
 622                                 // Allow unicode if a single high-bit character appears
 623                                 $r0 = sprintf( '\x%02x', $ord0 );
 624                                 $allowUnicode = true;
 625                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 626                                 $r0 = '\\' . $d0;
 627                         } else {
 628                                 $r0 = $d0;
 629                         }
 630                         // Do the output
 631                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 632                                 // Range
 633                                 if ( $ord2 > $ord0 ) {
 634                                         // Empty range
 635                                 } elseif ( $ord0 >= 0x80 ) {
 636                                         // Unicode range
 637                                         $allowUnicode = true;
 638                                         if ( $ord2 < 0x80 ) {
 639                                                 // Keep the non-unicode section of the range
 640                                                 $out .= "$r2-\\x7F";
 641                                         }
 642                                 } else {
 643                                         // Normal range
 644                                         $out .= "$r2-$r0";
 645                                 }
 646                                 // Reset state to the initial value
 647                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 648                         } elseif ( $ord2 < 0x80 ) {
 649                                 // ASCII character
 650                                 $out .= $r2;
 651                         }
 652                 }
 653                 if ( $ord1 < 0x80 ) {
 654                         $out .= $r1;
 655                 }
 656                 if ( $ord0 < 0x80 ) {
 657                         $out .= $r0;
 658                 }
 659                 if ( $allowUnicode ) {
 660                         $out .= '\u0080-\uFFFF';
 661                 }
 662                 return $out;
 663         }
 664
 665         /**
 666          * Get a string representation of a title suitable for
 667          * including in a search index
 668          *
 669          * @param int $ns a namespace index
 670          * @param string $title text-form main part
 671          * @return String a stripped-down title string ready for the search index
 672          */
 673         public static function indexTitle( $ns, $title ) {
 674                 global $wgContLang;
 675
 676                 $lc = SearchEngine::legalSearchChars() . '&#;';
 677                 $t = $wgContLang->normalizeForSearch( $title );
 678                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 679                 $t = $wgContLang->lc( $t );
 680
 681                 # Handle 's, s'
 682                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 683                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 684
 685                 $t = preg_replace( "/\\s+/", ' ', $t );
 686
 687                 if ( $ns == NS_FILE ) {
 688                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 689                 }
 690                 return trim( $t );
 691         }
 692
 693         /**
 694          * Make a prefixed DB key from a DB key and a namespace index
 695          *
 696          * @param int $ns numerical representation of the namespace
 697          * @param string $title the DB key form the title
 698          * @param string $fragment The link fragment (after the "#")
 699          * @param string $interwiki The interwiki prefix
 700          * @return String the prefixed form of the title
 701          */
 702         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 703                 global $wgContLang;
 704
 705                 $namespace = $wgContLang->getNsText( $ns );
 706                 $name = $namespace == '' ? $title : "$namespace:$title";
 707                 if ( strval( $interwiki ) != '' ) {
 708                         $name = "$interwiki:$name";
 709                 }
 710                 if ( strval( $fragment ) != '' ) {
 711                         $name .= '#' . $fragment;
 712                 }
 713                 return $name;
 714         }
 715
 716         /**
 717          * Escape a text fragment, say from a link, for a URL
 718          *
 719          * @param string $fragment containing a URL or link fragment (after the "#")
 720          * @return String: escaped string
 721          */
 722         static function escapeFragmentForURL( $fragment ) {
 723                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 724                 # fragments appear not to work in IE (at least up to 7) or in at least
 725                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 726                 # to care if they aren't encoded.
 727                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 728         }
 729
 730         /**
 731          * Callback for usort() to do title sorts by (namespace, title)
 732          *
 733          * @param $a Title
 734          * @param $b Title
 735          *
 736          * @return Integer: result of string comparison, or namespace comparison
 737          */
 738         public static function compare( $a, $b ) {
 739                 if ( $a->getNamespace() == $b->getNamespace() ) {
 740                         return strcmp( $a->getText(), $b->getText() );
 741                 } else {
 742                         return $a->getNamespace() - $b->getNamespace();
 743                 }
 744         }
 745
 746         /**
 747          * Determine whether the object refers to a page within
 748          * this project.
 749          *
 750          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 751          */
 752         public function isLocal() {
 753                 if ( $this->isExternal() ) {
 754                         $iw = Interwiki::fetch( $this->mInterwiki );
 755                         if ( $iw ) {
 756                                 return $iw->isLocal();
 757                         }
 758                 }
 759                 return true;
 760         }
 761
 762         /**
 763          * Is this Title interwiki?
 764          *
 765          * @return Bool
 766          */
 767         public function isExternal() {
 768                 return $this->mInterwiki !== '';
 769         }
 770
 771         /**
 772          * Get the interwiki prefix
 773          *
 774          * Use Title::isExternal to check if a interwiki is set
 775          *
 776          * @return String Interwiki prefix
 777          */
 778         public function getInterwiki() {
 779                 return $this->mInterwiki;
 780         }
 781
 782         /**
 783          * Determine whether the object refers to a page within
 784          * this project and is transcludable.
 785          *
 786          * @return Bool TRUE if this is transcludable
 787          */
 788         public function isTrans() {
 789                 if ( !$this->isExternal() ) {
 790                         return false;
 791                 }
 792
 793                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 794         }
 795
 796         /**
 797          * Returns the DB name of the distant wiki which owns the object.
 798          *
 799          * @return String the DB name
 800          */
 801         public function getTransWikiID() {
 802                 if ( !$this->isExternal() ) {
 803                         return false;
 804                 }
 805
 806                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 807         }
 808
 809         /**
 810          * Get a TitleValue object representing this Title.
 811          *
 812          * @note: Not all valid Titles have a corresponding valid TitleValue
 813          * (e.g. TitleValues cannot represent page-local links that have a
 814          * fragment but no title text).
 815          *
 816          * @return TitleValue|null
 817          */
 818         public function getTitleValue() {
 819                 if ( $this->mTitleValue === null ) {
 820                         try {
 821                                 $this->mTitleValue = new TitleValue(
 822                                         $this->getNamespace(),
 823                                         $this->getDBkey(),
 824                                         $this->getFragment() );
 825                         } catch ( InvalidArgumentException $ex ) {
 826                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 827                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 828                         }
 829                 }
 830
 831                 return $this->mTitleValue;
 832         }
 833
 834         /**
 835          * Get the text form (spaces not underscores) of the main part
 836          *
 837          * @return String Main part of the title
 838          */
 839         public function getText() {
 840                 return $this->mTextform;
 841         }
 842
 843         /**
 844          * Get the URL-encoded form of the main part
 845          *
 846          * @return String Main part of the title, URL-encoded
 847          */
 848         public function getPartialURL() {
 849                 return $this->mUrlform;
 850         }
 851
 852         /**
 853          * Get the main part with underscores
 854          *
 855          * @return String: Main part of the title, with underscores
 856          */
 857         public function getDBkey() {
 858                 return $this->mDbkeyform;
 859         }
 860
 861         /**
 862          * Get the DB key with the initial letter case as specified by the user
 863          *
 864          * @return String DB key
 865          */
 866         function getUserCaseDBKey() {
 867                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 868                         return $this->mUserCaseDBKey;
 869                 } else {
 870                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 871                         return $this->mDbkeyform;
 872                 }
 873         }
 874
 875         /**
 876          * Get the namespace index, i.e. one of the NS_xxxx constants.
 877          *
 878          * @return Integer: Namespace index
 879          */
 880         public function getNamespace() {
 881                 return $this->mNamespace;
 882         }
 883
 884         /**
 885          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 886          *
 887          * @throws MWException
 888          * @return String: Content model id
 889          */
 890         public function getContentModel() {
 891                 if ( !$this->mContentModel ) {
 892                         $linkCache = LinkCache::singleton();
 893                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 894                 }
 895
 896                 if ( !$this->mContentModel ) {
 897                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 898                 }
 899
 900                 if ( !$this->mContentModel ) {
 901                         throw new MWException( 'Failed to determine content model!' );
 902                 }
 903
 904                 return $this->mContentModel;
 905         }
 906
 907         /**
 908          * Convenience method for checking a title's content model name
 909          *
 910          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 911          * @return Boolean true if $this->getContentModel() == $id
 912          */
 913         public function hasContentModel( $id ) {
 914                 return $this->getContentModel() == $id;
 915         }
 916
 917         /**
 918          * Get the namespace text
 919          *
 920          * @return String: Namespace text
 921          */
 922         public function getNsText() {
 923                 if ( $this->isExternal() ) {
 924                         // This probably shouldn't even happen. ohh man, oh yuck.
 925                         // But for interwiki transclusion it sometimes does.
 926                         // Shit. Shit shit shit.
 927                         //
 928                         // Use the canonical namespaces if possible to try to
 929                         // resolve a foreign namespace.
 930                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 931                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 932                         }
 933                 }
 934
 935                 try {
 936                         $formatter = $this->getTitleFormatter();
 937                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 938                 } catch ( InvalidArgumentException $ex )  {
 939                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 940                         return false;
 941                 }
 942         }
 943
 944         /**
 945          * Get the namespace text of the subject (rather than talk) page
 946          *
 947          * @return String Namespace text
 948          */
 949         public function getSubjectNsText() {
 950                 global $wgContLang;
 951                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 952         }
 953
 954         /**
 955          * Get the namespace text of the talk page
 956          *
 957          * @return String Namespace text
 958          */
 959         public function getTalkNsText() {
 960                 global $wgContLang;
 961                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
 962         }
 963
 964         /**
 965          * Could this title have a corresponding talk page?
 966          *
 967          * @return Bool TRUE or FALSE
 968          */
 969         public function canTalk() {
 970                 return MWNamespace::canTalk( $this->mNamespace );
 971         }
 972
 973         /**
 974          * Is this in a namespace that allows actual pages?
 975          *
 976          * @return Bool
 977          * @internal note -- uses hardcoded namespace index instead of constants
 978          */
 979         public function canExist() {
 980                 return $this->mNamespace >= NS_MAIN;
 981         }
 982
 983         /**
 984          * Can this title be added to a user's watchlist?
 985          *
 986          * @return Bool TRUE or FALSE
 987          */
 988         public function isWatchable() {
 989                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 990         }
 991
 992         /**
 993          * Returns true if this is a special page.
 994          *
 995          * @return boolean
 996          */
 997         public function isSpecialPage() {
 998                 return $this->getNamespace() == NS_SPECIAL;
 999         }
1000
1001         /**
1002          * Returns true if this title resolves to the named special page
1003          *
1004          * @param string $name The special page name
1005          * @return boolean
1006          */
1007         public function isSpecial( $name ) {
1008                 if ( $this->isSpecialPage() ) {
1009                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1010                         if ( $name == $thisName ) {
1011                                 return true;
1012                         }
1013                 }
1014                 return false;
1015         }
1016
1017         /**
1018          * If the Title refers to a special page alias which is not the local default, resolve
1019          * the alias, and localise the name as necessary.  Otherwise, return $this
1020          *
1021          * @return Title
1022          */
1023         public function fixSpecialName() {
1024                 if ( $this->isSpecialPage() ) {
1025                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1026                         if ( $canonicalName ) {
1027                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1028                                 if ( $localName != $this->mDbkeyform ) {
1029                                         return Title::makeTitle( NS_SPECIAL, $localName );
1030                                 }
1031                         }
1032                 }
1033                 return $this;
1034         }
1035
1036         /**
1037          * Returns true if the title is inside the specified namespace.
1038          *
1039          * Please make use of this instead of comparing to getNamespace()
1040          * This function is much more resistant to changes we may make
1041          * to namespaces than code that makes direct comparisons.
1042          * @param int $ns The namespace
1043          * @return bool
1044          * @since 1.19
1045          */
1046         public function inNamespace( $ns ) {
1047                 return MWNamespace::equals( $this->getNamespace(), $ns );
1048         }
1049
1050         /**
1051          * Returns true if the title is inside one of the specified namespaces.
1052          *
1053          * @param ...$namespaces The namespaces to check for
1054          * @return bool
1055          * @since 1.19
1056          */
1057         public function inNamespaces( /* ... */ ) {
1058                 $namespaces = func_get_args();
1059                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1060                         $namespaces = $namespaces[0];
1061                 }
1062
1063                 foreach ( $namespaces as $ns ) {
1064                         if ( $this->inNamespace( $ns ) ) {
1065                                 return true;
1066                         }
1067                 }
1068
1069                 return false;
1070         }
1071
1072         /**
1073          * Returns true if the title has the same subject namespace as the
1074          * namespace specified.
1075          * For example this method will take NS_USER and return true if namespace
1076          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1077          * as their subject namespace.
1078          *
1079          * This is MUCH simpler than individually testing for equivalence
1080          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1081          * @since 1.19
1082          * @param $ns int
1083          * @return bool
1084          */
1085         public function hasSubjectNamespace( $ns ) {
1086                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1087         }
1088
1089         /**
1090          * Is this Title in a namespace which contains content?
1091          * In other words, is this a content page, for the purposes of calculating
1092          * statistics, etc?
1093          *
1094          * @return Boolean
1095          */
1096         public function isContentPage() {
1097                 return MWNamespace::isContent( $this->getNamespace() );
1098         }
1099
1100         /**
1101          * Would anybody with sufficient privileges be able to move this page?
1102          * Some pages just aren't movable.
1103          *
1104          * @return Bool TRUE or FALSE
1105          */
1106         public function isMovable() {
1107                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1108                         // Interwiki title or immovable namespace. Hooks don't get to override here
1109                         return false;
1110                 }
1111
1112                 $result = true;
1113                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1114                 return $result;
1115         }
1116
1117         /**
1118          * Is this the mainpage?
1119          * @note Title::newFromText seems to be sufficiently optimized by the title
1120          * cache that we don't need to over-optimize by doing direct comparisons and
1121          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1122          * ends up reporting something differently than $title->isMainPage();
1123          *
1124          * @since 1.18
1125          * @return Bool
1126          */
1127         public function isMainPage() {
1128                 return $this->equals( Title::newMainPage() );
1129         }
1130
1131         /**
1132          * Is this a subpage?
1133          *
1134          * @return Bool
1135          */
1136         public function isSubpage() {
1137                 return MWNamespace::hasSubpages( $this->mNamespace )
1138                         ? strpos( $this->getText(), '/' ) !== false
1139                         : false;
1140         }
1141
1142         /**
1143          * Is this a conversion table for the LanguageConverter?
1144          *
1145          * @return Bool
1146          */
1147         public function isConversionTable() {
1148                 // @todo ConversionTable should become a separate content model.
1149
1150                 return $this->getNamespace() == NS_MEDIAWIKI &&
1151                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1152         }
1153
1154         /**
1155          * Does that page contain wikitext, or it is JS, CSS or whatever?
1156          *
1157          * @return Bool
1158          */
1159         public function isWikitextPage() {
1160                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1161         }
1162
1163         /**
1164          * Could this page contain custom CSS or JavaScript for the global UI.
1165          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1166          * or CONTENT_MODEL_JAVASCRIPT.
1167          *
1168          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
1169          *
1170          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
1171          *
1172          * @return Bool
1173          */
1174         public function isCssOrJsPage() {
1175                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1176                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1177                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1178
1179                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
1180                 #      hook functions can force this method to return true even outside the mediawiki namespace.
1181
1182                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
1183
1184                 return $isCssOrJsPage;
1185         }
1186
1187         /**
1188          * Is this a .css or .js subpage of a user page?
1189          * @return Bool
1190          */
1191         public function isCssJsSubpage() {
1192                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1193                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1194                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1195         }
1196
1197         /**
1198          * Trim down a .css or .js subpage title to get the corresponding skin name
1199          *
1200          * @return string containing skin name from .css or .js subpage title
1201          */
1202         public function getSkinFromCssJsSubpage() {
1203                 $subpage = explode( '/', $this->mTextform );
1204                 $subpage = $subpage[count( $subpage ) - 1];
1205                 $lastdot = strrpos( $subpage, '.' );
1206                 if ( $lastdot === false ) {
1207                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1208                 }
1209                 return substr( $subpage, 0, $lastdot );
1210         }
1211
1212         /**
1213          * Is this a .css subpage of a user page?
1214          *
1215          * @return Bool
1216          */
1217         public function isCssSubpage() {
1218                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1219                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1220         }
1221
1222         /**
1223          * Is this a .js subpage of a user page?
1224          *
1225          * @return Bool
1226          */
1227         public function isJsSubpage() {
1228                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1229                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1230         }
1231
1232         /**
1233          * Is this a talk page of some sort?
1234          *
1235          * @return Bool
1236          */
1237         public function isTalkPage() {
1238                 return MWNamespace::isTalk( $this->getNamespace() );
1239         }
1240
1241         /**
1242          * Get a Title object associated with the talk page of this article
1243          *
1244          * @return Title the object for the talk page
1245          */
1246         public function getTalkPage() {
1247                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1248         }
1249
1250         /**
1251          * Get a title object associated with the subject page of this
1252          * talk page
1253          *
1254          * @return Title the object for the subject page
1255          */
1256         public function getSubjectPage() {
1257                 // Is this the same title?
1258                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1259                 if ( $this->getNamespace() == $subjectNS ) {
1260                         return $this;
1261                 }
1262                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1263         }
1264
1265         /**
1266          * Get the default namespace index, for when there is no namespace
1267          *
1268          * @return Int Default namespace index
1269          */
1270         public function getDefaultNamespace() {
1271                 return $this->mDefaultNamespace;
1272         }
1273
1274         /**
1275          * Get title for search index
1276          *
1277          * @return String a stripped-down title string ready for the
1278          *  search index
1279          */
1280         public function getIndexTitle() {
1281                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1282         }
1283
1284         /**
1285          * Get the Title fragment (i.e.\ the bit after the #) in text form
1286          *
1287          * Use Title::hasFragment to check for a fragment
1288          *
1289          * @return String Title fragment
1290          */
1291         public function getFragment() {
1292                 return $this->mFragment;
1293         }
1294
1295         /**
1296          * Check if a Title fragment is set
1297          *
1298          * @return bool
1299          * @since 1.23
1300          */
1301         public function hasFragment() {
1302                 return $this->mFragment !== '';
1303         }
1304
1305         /**
1306          * Get the fragment in URL form, including the "#" character if there is one
1307          * @return String Fragment in URL form
1308          */
1309         public function getFragmentForURL() {
1310                 if ( !$this->hasFragment() ) {
1311                         return '';
1312                 } else {
1313                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1314                 }
1315         }
1316
1317         /**
1318          * Set the fragment for this title. Removes the first character from the
1319          * specified fragment before setting, so it assumes you're passing it with
1320          * an initial "#".
1321          *
1322          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1323          * Still in active use privately.
1324          *
1325          * @param string $fragment text
1326          */
1327         public function setFragment( $fragment ) {
1328                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1329         }
1330
1331         /**
1332          * Prefix some arbitrary text with the namespace or interwiki prefix
1333          * of this object
1334          *
1335          * @param string $name the text
1336          * @return String the prefixed text
1337          * @private
1338          */
1339         private function prefix( $name ) {
1340                 $p = '';
1341                 if ( $this->isExternal() ) {
1342                         $p = $this->mInterwiki . ':';
1343                 }
1344
1345                 if ( 0 != $this->mNamespace ) {
1346                         $p .= $this->getNsText() . ':';
1347                 }
1348                 return $p . $name;
1349         }
1350
1351         /**
1352          * Get the prefixed database key form
1353          *
1354          * @return String the prefixed title, with underscores and
1355          *  any interwiki and namespace prefixes
1356          */
1357         public function getPrefixedDBkey() {
1358                 $s = $this->prefix( $this->mDbkeyform );
1359                 $s = str_replace( ' ', '_', $s );
1360                 return $s;
1361         }
1362
1363         /**
1364          * Get the prefixed title with spaces.
1365          * This is the form usually used for display
1366          *
1367          * @return String the prefixed title, with spaces
1368          */
1369         public function getPrefixedText() {
1370                 if ( $this->mPrefixedText === null ) {
1371                         $s = $this->prefix( $this->mTextform );
1372                         $s = str_replace( '_', ' ', $s );
1373                         $this->mPrefixedText = $s;
1374                 }
1375                 return $this->mPrefixedText;
1376         }
1377
1378         /**
1379          * Return a string representation of this title
1380          *
1381          * @return String representation of this title
1382          */
1383         public function __toString() {
1384                 return $this->getPrefixedText();
1385         }
1386
1387         /**
1388          * Get the prefixed title with spaces, plus any fragment
1389          * (part beginning with '#')
1390          *
1391          * @return String the prefixed title, with spaces and the fragment, including '#'
1392          */
1393         public function getFullText() {
1394                 $text = $this->getPrefixedText();
1395                 if ( $this->hasFragment() ) {
1396                         $text .= '#' . $this->getFragment();
1397                 }
1398                 return $text;
1399         }
1400
1401         /**
1402          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1403          *
1404          * @par Example:
1405          * @code
1406          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1407          * # returns: 'Foo'
1408          * @endcode
1409          *
1410          * @return String Root name
1411          * @since 1.20
1412          */
1413         public function getRootText() {
1414                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1415                         return $this->getText();
1416                 }
1417
1418                 return strtok( $this->getText(), '/' );
1419         }
1420
1421         /**
1422          * Get the root page name title, i.e. the leftmost part before any slashes
1423          *
1424          * @par Example:
1425          * @code
1426          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1427          * # returns: Title{User:Foo}
1428          * @endcode
1429          *
1430          * @return Title Root title
1431          * @since 1.20
1432          */
1433         public function getRootTitle() {
1434                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1435         }
1436
1437         /**
1438          * Get the base page name without a namespace, i.e. the part before the subpage name
1439          *
1440          * @par Example:
1441          * @code
1442          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1443          * # returns: 'Foo/Bar'
1444          * @endcode
1445          *
1446          * @return String Base name
1447          */
1448         public function getBaseText() {
1449                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1450                         return $this->getText();
1451                 }
1452
1453                 $parts = explode( '/', $this->getText() );
1454                 # Don't discard the real title if there's no subpage involved
1455                 if ( count( $parts ) > 1 ) {
1456                         unset( $parts[count( $parts ) - 1] );
1457                 }
1458                 return implode( '/', $parts );
1459         }
1460
1461         /**
1462          * Get the base page name title, i.e. the part before the subpage name
1463          *
1464          * @par Example:
1465          * @code
1466          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1467          * # returns: Title{User:Foo/Bar}
1468          * @endcode
1469          *
1470          * @return Title Base title
1471          * @since 1.20
1472          */
1473         public function getBaseTitle() {
1474                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1475         }
1476
1477         /**
1478          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1479          *
1480          * @par Example:
1481          * @code
1482          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1483          * # returns: "Baz"
1484          * @endcode
1485          *
1486          * @return String Subpage name
1487          */
1488         public function getSubpageText() {
1489                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1490                         return $this->mTextform;
1491                 }
1492                 $parts = explode( '/', $this->mTextform );
1493                 return $parts[count( $parts ) - 1];
1494         }
1495
1496         /**
1497          * Get the title for a subpage of the current page
1498          *
1499          * @par Example:
1500          * @code
1501          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1502          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1503          * @endcode
1504          *
1505          * @param string $text The subpage name to add to the title
1506          * @return Title Subpage title
1507          * @since 1.20
1508          */
1509         public function getSubpage( $text ) {
1510                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1511         }
1512
1513         /**
1514          * Get the HTML-escaped displayable text form.
1515          * Used for the title field in <a> tags.
1516          *
1517          * @return String the text, including any prefixes
1518          * @deprecated since 1.19
1519          */
1520         public function getEscapedText() {
1521                 wfDeprecated( __METHOD__, '1.19' );
1522                 return htmlspecialchars( $this->getPrefixedText() );
1523         }
1524
1525         /**
1526          * Get a URL-encoded form of the subpage text
1527          *
1528          * @return String URL-encoded subpage name
1529          */
1530         public function getSubpageUrlForm() {
1531                 $text = $this->getSubpageText();
1532                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1533                 return $text;
1534         }
1535
1536         /**
1537          * Get a URL-encoded title (not an actual URL) including interwiki
1538          *
1539          * @return String the URL-encoded form
1540          */
1541         public function getPrefixedURL() {
1542                 $s = $this->prefix( $this->mDbkeyform );
1543                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1544                 return $s;
1545         }
1546
1547         /**
1548          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1549          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1550          * second argument named variant. This was deprecated in favor
1551          * of passing an array of option with a "variant" key
1552          * Once $query2 is removed for good, this helper can be dropped
1553          * and the wfArrayToCgi moved to getLocalURL();
1554          *
1555          * @since 1.19 (r105919)
1556          * @param $query
1557          * @param $query2 bool
1558          * @return String
1559          */
1560         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1561                 if ( $query2 !== false ) {
1562                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1563                                 "method called with a second parameter is deprecated. Add your " .
1564                                 "parameter to an array passed as the first parameter.", "1.19" );
1565                 }
1566                 if ( is_array( $query ) ) {
1567                         $query = wfArrayToCgi( $query );
1568                 }
1569                 if ( $query2 ) {
1570                         if ( is_string( $query2 ) ) {
1571                                 // $query2 is a string, we will consider this to be
1572                                 // a deprecated $variant argument and add it to the query
1573                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1574                         } else {
1575                                 $query2 = wfArrayToCgi( $query2 );
1576                         }
1577                         // If we have $query content add a & to it first
1578                         if ( $query ) {
1579                                 $query .= '&';
1580                         }
1581                         // Now append the queries together
1582                         $query .= $query2;
1583                 }
1584                 return $query;
1585         }
1586
1587         /**
1588          * Get a real URL referring to this title, with interwiki link and
1589          * fragment
1590          *
1591          * @see self::getLocalURL for the arguments.
1592          * @see wfExpandUrl
1593          * @param $query
1594          * @param $query2 bool
1595          * @param $proto Protocol type to use in URL
1596          * @return String the URL
1597          */
1598         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1599                 $query = self::fixUrlQueryArgs( $query, $query2 );
1600
1601                 # Hand off all the decisions on urls to getLocalURL
1602                 $url = $this->getLocalURL( $query );
1603
1604                 # Expand the url to make it a full url. Note that getLocalURL has the
1605                 # potential to output full urls for a variety of reasons, so we use
1606                 # wfExpandUrl instead of simply prepending $wgServer
1607                 $url = wfExpandUrl( $url, $proto );
1608
1609                 # Finally, add the fragment.
1610                 $url .= $this->getFragmentForURL();
1611
1612                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1613                 return $url;
1614         }
1615
1616         /**
1617          * Get a URL with no fragment or server name (relative URL) from a Title object.
1618          * If this page is generated with action=render, however,
1619          * $wgServer is prepended to make an absolute URL.
1620          *
1621          * @see self::getFullURL to always get an absolute URL.
1622          * @see self::newFromText to produce a Title object.
1623          *
1624          * @param string|array $query an optional query string,
1625          *   not used for interwiki links. Can be specified as an associative array as well,
1626          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1627          *   Some query patterns will trigger various shorturl path replacements.
1628          * @param $query2 Mixed: An optional secondary query array. This one MUST
1629          *   be an array. If a string is passed it will be interpreted as a deprecated
1630          *   variant argument and urlencoded into a variant= argument.
1631          *   This second query argument will be added to the $query
1632          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1633          *   pair in the first parameter array instead.
1634          *
1635          * @return String of the URL.
1636          */
1637         public function getLocalURL( $query = '', $query2 = false ) {
1638                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1639
1640                 $query = self::fixUrlQueryArgs( $query, $query2 );
1641
1642                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1643                 if ( $interwiki ) {
1644                         $namespace = $this->getNsText();
1645                         if ( $namespace != '' ) {
1646                                 # Can this actually happen? Interwikis shouldn't be parsed.
1647                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1648                                 $namespace .= ':';
1649                         }
1650                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1651                         $url = wfAppendQuery( $url, $query );
1652                 } else {
1653                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1654                         if ( $query == '' ) {
1655                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1656                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1657                         } else {
1658                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1659                                 $url = false;
1660                                 $matches = array();
1661
1662                                 if ( !empty( $wgActionPaths )
1663                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1664                                 ) {
1665                                         $action = urldecode( $matches[2] );
1666                                         if ( isset( $wgActionPaths[$action] ) ) {
1667                                                 $query = $matches[1];
1668                                                 if ( isset( $matches[4] ) ) {
1669                                                         $query .= $matches[4];
1670                                                 }
1671                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1672                                                 if ( $query != '' ) {
1673                                                         $url = wfAppendQuery( $url, $query );
1674                                                 }
1675                                         }
1676                                 }
1677
1678                                 if ( $url === false
1679                                         && $wgVariantArticlePath
1680                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1681                                         && $this->getPageLanguage()->hasVariants()
1682                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1683                                 ) {
1684                                         $variant = urldecode( $matches[1] );
1685                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1686                                                 // Only do the variant replacement if the given variant is a valid
1687                                                 // variant for the page's language.
1688                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1689                                                 $url = str_replace( '$1', $dbkey, $url );
1690                                         }
1691                                 }
1692
1693                                 if ( $url === false ) {
1694                                         if ( $query == '-' ) {
1695                                                 $query = '';
1696                                         }
1697                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1698                                 }
1699                         }
1700
1701                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1702
1703                         // @todo FIXME: This causes breakage in various places when we
1704                         // actually expected a local URL and end up with dupe prefixes.
1705                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1706                                 $url = $wgServer . $url;
1707                         }
1708                 }
1709                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1710                 return $url;
1711         }
1712
1713         /**
1714          * Get a URL that's the simplest URL that will be valid to link, locally,
1715          * to the current Title.  It includes the fragment, but does not include
1716          * the server unless action=render is used (or the link is external).  If
1717          * there's a fragment but the prefixed text is empty, we just return a link
1718          * to the fragment.
1719          *
1720          * The result obviously should not be URL-escaped, but does need to be
1721          * HTML-escaped if it's being output in HTML.
1722          *
1723          * @param $query
1724          * @param $query2 bool
1725          * @param $proto Protocol to use; setting this will cause a full URL to be used
1726          * @see self::getLocalURL for the arguments.
1727          * @return String the URL
1728          */
1729         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1730                 wfProfileIn( __METHOD__ );
1731                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1732                         $ret = $this->getFullURL( $query, $query2, $proto );
1733                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1734                         $ret = $this->getFragmentForURL();
1735                 } else {
1736                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1737                 }
1738                 wfProfileOut( __METHOD__ );
1739                 return $ret;
1740         }
1741
1742         /**
1743          * Get an HTML-escaped version of the URL form, suitable for
1744          * using in a link, without a server name or fragment
1745          *
1746          * @see self::getLocalURL for the arguments.
1747          * @param $query string
1748          * @param $query2 bool|string
1749          * @return String the URL
1750          * @deprecated since 1.19
1751          */
1752         public function escapeLocalURL( $query = '', $query2 = false ) {
1753                 wfDeprecated( __METHOD__, '1.19' );
1754                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1755         }
1756
1757         /**
1758          * Get an HTML-escaped version of the URL form, suitable for
1759          * using in a link, including the server name and fragment
1760          *
1761          * @see self::getLocalURL for the arguments.
1762          * @return String the URL
1763          * @deprecated since 1.19
1764          */
1765         public function escapeFullURL( $query = '', $query2 = false ) {
1766                 wfDeprecated( __METHOD__, '1.19' );
1767                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1768         }
1769
1770         /**
1771          * Get the URL form for an internal link.
1772          * - Used in various Squid-related code, in case we have a different
1773          * internal hostname for the server from the exposed one.
1774          *
1775          * This uses $wgInternalServer to qualify the path, or $wgServer
1776          * if $wgInternalServer is not set. If the server variable used is
1777          * protocol-relative, the URL will be expanded to http://
1778          *
1779          * @see self::getLocalURL for the arguments.
1780          * @return String the URL
1781          */
1782         public function getInternalURL( $query = '', $query2 = false ) {
1783                 global $wgInternalServer, $wgServer;
1784                 $query = self::fixUrlQueryArgs( $query, $query2 );
1785                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1786                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1787                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1788                 return $url;
1789         }
1790
1791         /**
1792          * Get the URL for a canonical link, for use in things like IRC and
1793          * e-mail notifications. Uses $wgCanonicalServer and the
1794          * GetCanonicalURL hook.
1795          *
1796          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1797          *
1798          * @see self::getLocalURL for the arguments.
1799          * @return string The URL
1800          * @since 1.18
1801          */
1802         public function getCanonicalURL( $query = '', $query2 = false ) {
1803                 $query = self::fixUrlQueryArgs( $query, $query2 );
1804                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1805                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1806                 return $url;
1807         }
1808
1809         /**
1810          * HTML-escaped version of getCanonicalURL()
1811          *
1812          * @see self::getLocalURL for the arguments.
1813          * @since 1.18
1814          * @return string
1815          * @deprecated since 1.19
1816          */
1817         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1818                 wfDeprecated( __METHOD__, '1.19' );
1819                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1820         }
1821
1822         /**
1823          * Get the edit URL for this Title
1824          *
1825          * @return String the URL, or a null string if this is an
1826          *  interwiki link
1827          */
1828         public function getEditURL() {
1829                 if ( $this->isExternal() ) {
1830                         return '';
1831                 }
1832                 $s = $this->getLocalURL( 'action=edit' );
1833
1834                 return $s;
1835         }
1836
1837         /**
1838          * Is $wgUser watching this page?
1839          *
1840          * @deprecated in 1.20; use User::isWatched() instead.
1841          * @return Bool
1842          */
1843         public function userIsWatching() {
1844                 global $wgUser;
1845
1846                 if ( is_null( $this->mWatched ) ) {
1847                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1848                                 $this->mWatched = false;
1849                         } else {
1850                                 $this->mWatched = $wgUser->isWatched( $this );
1851                         }
1852                 }
1853                 return $this->mWatched;
1854         }
1855
1856         /**
1857          * Can $wgUser read this page?
1858          *
1859          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1860          * @return Bool
1861          */
1862         public function userCanRead() {
1863                 wfDeprecated( __METHOD__, '1.19' );
1864                 return $this->userCan( 'read' );
1865         }
1866
1867         /**
1868          * Can $user perform $action on this page?
1869          * This skips potentially expensive cascading permission checks
1870          * as well as avoids expensive error formatting
1871          *
1872          * Suitable for use for nonessential UI controls in common cases, but
1873          * _not_ for functional access control.
1874          *
1875          * May provide false positives, but should never provide a false negative.
1876          *
1877          * @param string $action action that permission needs to be checked for
1878          * @param $user User to check (since 1.19); $wgUser will be used if not
1879          *              provided.
1880          * @return Bool
1881          */
1882         public function quickUserCan( $action, $user = null ) {
1883                 return $this->userCan( $action, $user, false );
1884         }
1885
1886         /**
1887          * Can $user perform $action on this page?
1888          *
1889          * @param string $action action that permission needs to be checked for
1890          * @param $user User to check (since 1.19); $wgUser will be used if not
1891          *   provided.
1892          * @param bool $doExpensiveQueries Set this to false to avoid doing
1893          *   unnecessary queries.
1894          * @return Bool
1895          */
1896         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1897                 if ( !$user instanceof User ) {
1898                         global $wgUser;
1899                         $user = $wgUser;
1900                 }
1901                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1902         }
1903
1904         /**
1905          * Can $user perform $action on this page?
1906          *
1907          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1908          *
1909          * @param string $action action that permission needs to be checked for
1910          * @param $user User to check
1911          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1912          *   queries by skipping checks for cascading protections and user blocks.
1913          * @param array $ignoreErrors of Strings Set this to a list of message keys
1914          *   whose corresponding errors may be ignored.
1915          * @return Array of arguments to wfMessage to explain permissions problems.
1916          */
1917         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1918                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1919
1920                 // Remove the errors being ignored.
1921                 foreach ( $errors as $index => $error ) {
1922                         $error_key = is_array( $error ) ? $error[0] : $error;
1923
1924                         if ( in_array( $error_key, $ignoreErrors ) ) {
1925                                 unset( $errors[$index] );
1926                         }
1927                 }
1928
1929                 return $errors;
1930         }
1931
1932         /**
1933          * Permissions checks that fail most often, and which are easiest to test.
1934          *
1935          * @param string $action the action to check
1936          * @param $user User user to check
1937          * @param array $errors list of current errors
1938          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1939          * @param $short Boolean short circuit on first error
1940          *
1941          * @return Array list of errors
1942          */
1943         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1944                 if ( !wfRunHooks( 'TitleQuickPermissions', array( $this, $user, $action, &$errors, $doExpensiveQueries, $short ) ) ) {
1945                         return $errors;
1946                 }
1947
1948                 if ( $action == 'create' ) {
1949                         if (
1950                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1951                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1952                         ) {
1953                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1954                         }
1955                 } elseif ( $action == 'move' ) {
1956                         if ( !$user->isAllowed( 'move-rootuserpages' )
1957                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1958                                 // Show user page-specific message only if the user can move other pages
1959                                 $errors[] = array( 'cant-move-user-page' );
1960                         }
1961
1962                         // Check if user is allowed to move files if it's a file
1963                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1964                                 $errors[] = array( 'movenotallowedfile' );
1965                         }
1966
1967                         if ( !$user->isAllowed( 'move' ) ) {
1968                                 // User can't move anything
1969                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1970                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1971                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1972                                         // custom message if logged-in users without any special rights can move
1973                                         $errors[] = array( 'movenologintext' );
1974                                 } else {
1975                                         $errors[] = array( 'movenotallowed' );
1976                                 }
1977                         }
1978                 } elseif ( $action == 'move-target' ) {
1979                         if ( !$user->isAllowed( 'move' ) ) {
1980                                 // User can't move anything
1981                                 $errors[] = array( 'movenotallowed' );
1982                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1983                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1984                                 // Show user page-specific message only if the user can move other pages
1985                                 $errors[] = array( 'cant-move-to-user-page' );
1986                         }
1987                 } elseif ( !$user->isAllowed( $action ) ) {
1988                         $errors[] = $this->missingPermissionError( $action, $short );
1989                 }
1990
1991                 return $errors;
1992         }
1993
1994         /**
1995          * Add the resulting error code to the errors array
1996          *
1997          * @param array $errors list of current errors
1998          * @param $result Mixed result of errors
1999          *
2000          * @return Array list of errors
2001          */
2002         private function resultToError( $errors, $result ) {
2003                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2004                         // A single array representing an error
2005                         $errors[] = $result;
2006                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2007                         // A nested array representing multiple errors
2008                         $errors = array_merge( $errors, $result );
2009                 } elseif ( $result !== '' && is_string( $result ) ) {
2010                         // A string representing a message-id
2011                         $errors[] = array( $result );
2012                 } elseif ( $result === false ) {
2013                         // a generic "We don't want them to do that"
2014                         $errors[] = array( 'badaccess-group0' );
2015                 }
2016                 return $errors;
2017         }
2018
2019         /**
2020          * Check various permission hooks
2021          *
2022          * @param string $action the action to check
2023          * @param $user User user to check
2024          * @param array $errors list of current errors
2025          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2026          * @param $short Boolean short circuit on first error
2027          *
2028          * @return Array list of errors
2029          */
2030         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
2031                 // Use getUserPermissionsErrors instead
2032                 $result = '';
2033                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2034                         return $result ? array() : array( array( 'badaccess-group0' ) );
2035                 }
2036                 // Check getUserPermissionsErrors hook
2037                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2038                         $errors = $this->resultToError( $errors, $result );
2039                 }
2040                 // Check getUserPermissionsErrorsExpensive hook
2041                 if (
2042                         $doExpensiveQueries
2043                         && !( $short && count( $errors ) > 0 )
2044                         && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2045                 ) {
2046                         $errors = $this->resultToError( $errors, $result );
2047                 }
2048
2049                 return $errors;
2050         }
2051
2052         /**
2053          * Check permissions on special pages & namespaces
2054          *
2055          * @param string $action the action to check
2056          * @param $user User user to check
2057          * @param array $errors list of current errors
2058          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2059          * @param $short Boolean short circuit on first error
2060          *
2061          * @return Array list of errors
2062          */
2063         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2064                 # Only 'createaccount' can be performed on special pages,
2065                 # which don't actually exist in the DB.
2066                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2067                         $errors[] = array( 'ns-specialprotected' );
2068                 }
2069
2070                 # Check $wgNamespaceProtection for restricted namespaces
2071                 if ( $this->isNamespaceProtected( $user ) ) {
2072                         $ns = $this->mNamespace == NS_MAIN ?
2073                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2074                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2075                                 array( 'protectedinterface' ) : array( 'namespaceprotected', $ns );
2076                 }
2077
2078                 return $errors;
2079         }
2080
2081         /**
2082          * Check CSS/JS sub-page permissions
2083          *
2084          * @param string $action the action to check
2085          * @param $user User user to check
2086          * @param array $errors list of current errors
2087          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2088          * @param $short Boolean short circuit on first error
2089          *
2090          * @return Array list of errors
2091          */
2092         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2093                 # Protect css/js subpages of user pages
2094                 # XXX: this might be better using restrictions
2095                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2096                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2097                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2098                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2099                                         $errors[] = array( 'mycustomcssprotected' );
2100                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2101                                         $errors[] = array( 'mycustomjsprotected' );
2102                                 }
2103                         } else {
2104                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2105                                         $errors[] = array( 'customcssprotected' );
2106                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2107                                         $errors[] = array( 'customjsprotected' );
2108                                 }
2109                         }
2110                 }
2111
2112                 return $errors;
2113         }
2114
2115         /**
2116          * Check against page_restrictions table requirements on this
2117          * page. The user must possess all required rights for this
2118          * action.
2119          *
2120          * @param string $action the action to check
2121          * @param $user User user to check
2122          * @param array $errors list of current errors
2123          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2124          * @param $short Boolean short circuit on first error
2125          *
2126          * @return Array list of errors
2127          */
2128         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2129                 foreach ( $this->getRestrictions( $action ) as $right ) {
2130                         // Backwards compatibility, rewrite sysop -> editprotected
2131                         if ( $right == 'sysop' ) {
2132                                 $right = 'editprotected';
2133                         }
2134                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2135                         if ( $right == 'autoconfirmed' ) {
2136                                 $right = 'editsemiprotected';
2137                         }
2138                         if ( $right == '' ) {
2139                                 continue;
2140                         }
2141                         if ( !$user->isAllowed( $right ) ) {
2142                                 $errors[] = array( 'protectedpagetext', $right );
2143                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2144                                 $errors[] = array( 'protectedpagetext', 'protect' );
2145                         }
2146                 }
2147
2148                 return $errors;
2149         }
2150
2151         /**
2152          * Check restrictions on cascading pages.
2153          *
2154          * @param string $action the action to check
2155          * @param $user User to check
2156          * @param array $errors list of current errors
2157          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2158          * @param $short Boolean short circuit on first error
2159          *
2160          * @return Array list of errors
2161          */
2162         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2163                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
2164                         # We /could/ use the protection level on the source page, but it's
2165                         # fairly ugly as we have to establish a precedence hierarchy for pages
2166                         # included by multiple cascade-protected pages. So just restrict
2167                         # it to people with 'protect' permission, as they could remove the
2168                         # protection anyway.
2169                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2170                         # Cascading protection depends on more than this page...
2171                         # Several cascading protected pages may include this page...
2172                         # Check each cascading level
2173                         # This is only for protection restrictions, not for all actions
2174                         if ( isset( $restrictions[$action] ) ) {
2175                                 foreach ( $restrictions[$action] as $right ) {
2176                                         // Backwards compatibility, rewrite sysop -> editprotected
2177                                         if ( $right == 'sysop' ) {
2178                                                 $right = 'editprotected';
2179                                         }
2180                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2181                                         if ( $right == 'autoconfirmed' ) {
2182                                                 $right = 'editsemiprotected';
2183                                         }
2184                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2185                                                 $pages = '';
2186                                                 foreach ( $cascadingSources as $page ) {
2187                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2188                                                 }
2189                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
2190                                         }
2191                                 }
2192                         }
2193                 }
2194
2195                 return $errors;
2196         }
2197
2198         /**
2199          * Check action permissions not already checked in checkQuickPermissions
2200          *
2201          * @param string $action the action to check
2202          * @param $user User to check
2203          * @param array $errors list of current errors
2204          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2205          * @param $short Boolean short circuit on first error
2206          *
2207          * @return Array list of errors
2208          */
2209         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2210                 global $wgDeleteRevisionsLimit, $wgLang;
2211
2212                 if ( $action == 'protect' ) {
2213                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
2214                                 // If they can't edit, they shouldn't protect.
2215                                 $errors[] = array( 'protect-cantedit' );
2216                         }
2217                 } elseif ( $action == 'create' ) {
2218                         $title_protection = $this->getTitleProtection();
2219                         if ( $title_protection ) {
2220                                 if ( $title_protection['pt_create_perm'] == 'sysop' ) {
2221                                         $title_protection['pt_create_perm'] = 'editprotected'; // B/C
2222                                 }
2223                                 if ( $title_protection['pt_create_perm'] == 'autoconfirmed' ) {
2224                                         $title_protection['pt_create_perm'] = 'editsemiprotected'; // B/C
2225                                 }
2226                                 if ( $title_protection['pt_create_perm'] == ''
2227                                         || !$user->isAllowed( $title_protection['pt_create_perm'] )
2228                                 ) {
2229                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
2230                                 }
2231                         }
2232                 } elseif ( $action == 'move' ) {
2233                         // Check for immobile pages
2234                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2235                                 // Specific message for this case
2236                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2237                         } elseif ( !$this->isMovable() ) {
2238                                 // Less specific message for rarer cases
2239                                 $errors[] = array( 'immobile-source-page' );
2240                         }
2241                 } elseif ( $action == 'move-target' ) {
2242                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2243                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2244                         } elseif ( !$this->isMovable() ) {
2245                                 $errors[] = array( 'immobile-target-page' );
2246                         }
2247                 } elseif ( $action == 'delete' ) {
2248                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2249                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2250                         ) {
2251                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2252                         }
2253                 }
2254                 return $errors;
2255         }
2256
2257         /**
2258          * Check that the user isn't blocked from editing.
2259          *
2260          * @param string $action the action to check
2261          * @param $user User to check
2262          * @param array $errors list of current errors
2263          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2264          * @param $short Boolean short circuit on first error
2265          *
2266          * @return Array list of errors
2267          */
2268         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2269                 // Account creation blocks handled at userlogin.
2270                 // Unblocking handled in SpecialUnblock
2271                 if ( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2272                         return $errors;
2273                 }
2274
2275                 global $wgEmailConfirmToEdit;
2276
2277                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2278                         $errors[] = array( 'confirmedittext' );
2279                 }
2280
2281                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2282                         // Don't block the user from editing their own talk page unless they've been
2283                         // explicitly blocked from that too.
2284                 } elseif ( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2285                         // @todo FIXME: Pass the relevant context into this function.
2286                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2287                 }
2288
2289                 return $errors;
2290         }
2291
2292         /**
2293          * Check that the user is allowed to read this page.
2294          *
2295          * @param string $action the action to check
2296          * @param $user User to check
2297          * @param array $errors list of current errors
2298          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2299          * @param $short Boolean short circuit on first error
2300          *
2301          * @return Array list of errors
2302          */
2303         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2304                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2305
2306                 $whitelisted = false;
2307                 if ( User::isEveryoneAllowed( 'read' ) ) {
2308                         # Shortcut for public wikis, allows skipping quite a bit of code
2309                         $whitelisted = true;
2310                 } elseif ( $user->isAllowed( 'read' ) ) {
2311                         # If the user is allowed to read pages, he is allowed to read all pages
2312                         $whitelisted = true;
2313                 } elseif ( $this->isSpecial( 'Userlogin' )
2314                         || $this->isSpecial( 'ChangePassword' )
2315                         || $this->isSpecial( 'PasswordReset' )
2316                 ) {
2317                         # Always grant access to the login page.
2318                         # Even anons need to be able to log in.
2319                         $whitelisted = true;
2320                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2321                         # Time to check the whitelist
2322                         # Only do these checks is there's something to check against
2323                         $name = $this->getPrefixedText();
2324                         $dbName = $this->getPrefixedDBkey();
2325
2326                         // Check for explicit whitelisting with and without underscores
2327                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2328                                 $whitelisted = true;
2329                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2330                                 # Old settings might have the title prefixed with
2331                                 # a colon for main-namespace pages
2332                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2333                                         $whitelisted = true;
2334                                 }
2335                         } elseif ( $this->isSpecialPage() ) {
2336                                 # If it's a special page, ditch the subpage bit and check again
2337                                 $name = $this->getDBkey();
2338                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2339                                 if ( $name ) {
2340                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2341                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2342                                                 $whitelisted = true;
2343                                         }
2344                                 }
2345                         }
2346                 }
2347
2348                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2349                         $name = $this->getPrefixedText();
2350                         // Check for regex whitelisting
2351                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2352                                 if ( preg_match( $listItem, $name ) ) {
2353                                         $whitelisted = true;
2354                                         break;
2355                                 }
2356                         }
2357                 }
2358
2359                 if ( !$whitelisted ) {
2360                         # If the title is not whitelisted, give extensions a chance to do so...
2361                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2362                         if ( !$whitelisted ) {
2363                                 $errors[] = $this->missingPermissionError( $action, $short );
2364                         }
2365                 }
2366
2367                 return $errors;
2368         }
2369
2370         /**
2371          * Get a description array when the user doesn't have the right to perform
2372          * $action (i.e. when User::isAllowed() returns false)
2373          *
2374          * @param string $action the action to check
2375          * @param $short Boolean short circuit on first error
2376          * @return Array list of errors
2377          */
2378         private function missingPermissionError( $action, $short ) {
2379                 // We avoid expensive display logic for quickUserCan's and such
2380                 if ( $short ) {
2381                         return array( 'badaccess-group0' );
2382                 }
2383
2384                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2385                         User::getGroupsWithPermission( $action ) );
2386
2387                 if ( count( $groups ) ) {
2388                         global $wgLang;
2389                         return array(
2390                                 'badaccess-groups',
2391                                 $wgLang->commaList( $groups ),
2392                                 count( $groups )
2393                         );
2394                 } else {
2395                         return array( 'badaccess-group0' );
2396                 }
2397         }
2398
2399         /**
2400          * Can $user perform $action on this page? This is an internal function,
2401          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2402          * checks on wfReadOnly() and blocks)
2403          *
2404          * @param string $action action that permission needs to be checked for
2405          * @param $user User to check
2406          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
2407          * @param bool $short Set this to true to stop after the first permission error.
2408          * @return Array of arrays of the arguments to wfMessage to explain permissions problems.
2409          */
2410         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2411                 wfProfileIn( __METHOD__ );
2412
2413                 # Read has special handling
2414                 if ( $action == 'read' ) {
2415                         $checks = array(
2416                                 'checkPermissionHooks',
2417                                 'checkReadPermissions',
2418                         );
2419                 } else {
2420                         $checks = array(
2421                                 'checkQuickPermissions',
2422                                 'checkPermissionHooks',
2423                                 'checkSpecialsAndNSPermissions',
2424                                 'checkCSSandJSPermissions',
2425                                 'checkPageRestrictions',
2426                                 'checkCascadingSourcesRestrictions',
2427                                 'checkActionPermissions',
2428                                 'checkUserBlock'
2429                         );
2430                 }
2431
2432                 $errors = array();
2433                 while ( count( $checks ) > 0 &&
2434                                 !( $short && count( $errors ) > 0 ) ) {
2435                         $method = array_shift( $checks );
2436                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2437                 }
2438
2439                 wfProfileOut( __METHOD__ );
2440                 return $errors;
2441         }
2442
2443         /**
2444          * Get a filtered list of all restriction types supported by this wiki.
2445          * @param bool $exists True to get all restriction types that apply to
2446          * titles that do exist, False for all restriction types that apply to
2447          * titles that do not exist
2448          * @return array
2449          */
2450         public static function getFilteredRestrictionTypes( $exists = true ) {
2451                 global $wgRestrictionTypes;
2452                 $types = $wgRestrictionTypes;
2453                 if ( $exists ) {
2454                         # Remove the create restriction for existing titles
2455                         $types = array_diff( $types, array( 'create' ) );
2456                 } else {
2457                         # Only the create and upload restrictions apply to non-existing titles
2458                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2459                 }
2460                 return $types;
2461         }
2462
2463         /**
2464          * Returns restriction types for the current Title
2465          *
2466          * @return array applicable restriction types
2467          */
2468         public function getRestrictionTypes() {
2469                 if ( $this->isSpecialPage() ) {
2470                         return array();
2471                 }
2472
2473                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2474
2475                 if ( $this->getNamespace() != NS_FILE ) {
2476                         # Remove the upload restriction for non-file titles
2477                         $types = array_diff( $types, array( 'upload' ) );
2478                 }
2479
2480                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2481
2482                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2483                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2484
2485                 return $types;
2486         }
2487
2488         /**
2489          * Is this title subject to title protection?
2490          * Title protection is the one applied against creation of such title.
2491          *
2492          * @return Mixed An associative array representing any existent title
2493          *   protection, or false if there's none.
2494          */
2495         private function getTitleProtection() {
2496                 // Can't protect pages in special namespaces
2497                 if ( $this->getNamespace() < 0 ) {
2498                         return false;
2499                 }
2500
2501                 // Can't protect pages that exist.
2502                 if ( $this->exists() ) {
2503                         return false;
2504                 }
2505
2506                 if ( !isset( $this->mTitleProtection ) ) {
2507                         $dbr = wfGetDB( DB_SLAVE );
2508                         $res = $dbr->select(
2509                                 'protected_titles',
2510                                 array( 'pt_user', 'pt_reason', 'pt_expiry', 'pt_create_perm' ),
2511                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2512                                 __METHOD__
2513                         );
2514
2515                         // fetchRow returns false if there are no rows.
2516                         $this->mTitleProtection = $dbr->fetchRow( $res );
2517                 }
2518                 return $this->mTitleProtection;
2519         }
2520
2521         /**
2522          * Update the title protection status
2523          *
2524          * @deprecated in 1.19; use WikiPage::doUpdateRestrictions() instead.
2525          * @param $create_perm String Permission required for creation
2526          * @param string $reason Reason for protection
2527          * @param string $expiry Expiry timestamp
2528          * @return boolean true
2529          */
2530         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2531                 wfDeprecated( __METHOD__, '1.19' );
2532
2533                 global $wgUser;
2534
2535                 $limit = array( 'create' => $create_perm );
2536                 $expiry = array( 'create' => $expiry );
2537
2538                 $page = WikiPage::factory( $this );
2539                 $cascade = false;
2540                 $status = $page->doUpdateRestrictions( $limit, $expiry, $cascade, $reason, $wgUser );
2541
2542                 return $status->isOK();
2543         }
2544
2545         /**
2546          * Remove any title protection due to page existing
2547          */
2548         public function deleteTitleProtection() {
2549                 $dbw = wfGetDB( DB_MASTER );
2550
2551                 $dbw->delete(
2552                         'protected_titles',
2553                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2554                         __METHOD__
2555                 );
2556                 $this->mTitleProtection = false;
2557         }
2558
2559         /**
2560          * Is this page "semi-protected" - the *only* protection levels are listed
2561          * in $wgSemiprotectedRestrictionLevels?
2562          *
2563          * @param string $action Action to check (default: edit)
2564          * @return Bool
2565          */
2566         public function isSemiProtected( $action = 'edit' ) {
2567                 global $wgSemiprotectedRestrictionLevels;
2568
2569                 $restrictions = $this->getRestrictions( $action );
2570                 $semi = $wgSemiprotectedRestrictionLevels;
2571                 if ( !$restrictions || !$semi ) {
2572                         // Not protected, or all protection is full protection
2573                         return false;
2574                 }
2575
2576                 // Remap autoconfirmed to editsemiprotected for BC
2577                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2578                         $semi[$key] = 'editsemiprotected';
2579                 }
2580                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2581                         $restrictions[$key] = 'editsemiprotected';
2582                 }
2583
2584                 return !array_diff( $restrictions, $semi );
2585         }
2586
2587         /**
2588          * Does the title correspond to a protected article?
2589          *
2590          * @param string $action the action the page is protected from,
2591          * by default checks all actions.
2592          * @return Bool
2593          */
2594         public function isProtected( $action = '' ) {
2595                 global $wgRestrictionLevels;
2596
2597                 $restrictionTypes = $this->getRestrictionTypes();
2598
2599                 # Special pages have inherent protection
2600                 if ( $this->isSpecialPage() ) {
2601                         return true;
2602                 }
2603
2604                 # Check regular protection levels
2605                 foreach ( $restrictionTypes as $type ) {
2606                         if ( $action == $type || $action == '' ) {
2607                                 $r = $this->getRestrictions( $type );
2608                                 foreach ( $wgRestrictionLevels as $level ) {
2609                                         if ( in_array( $level, $r ) && $level != '' ) {
2610                                                 return true;
2611                                         }
2612                                 }
2613                         }
2614                 }
2615
2616                 return false;
2617         }
2618
2619         /**
2620          * Determines if $user is unable to edit this page because it has been protected
2621          * by $wgNamespaceProtection.
2622          *
2623          * @param $user User object to check permissions
2624          * @return Bool
2625          */
2626         public function isNamespaceProtected( User $user ) {
2627                 global $wgNamespaceProtection;
2628
2629                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2630                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2631                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2632                                         return true;
2633                                 }
2634                         }
2635                 }
2636                 return false;
2637         }
2638
2639         /**
2640          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2641          *
2642          * @return Bool If the page is subject to cascading restrictions.
2643          */
2644         public function isCascadeProtected() {
2645                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2646                 return ( $sources > 0 );
2647         }
2648
2649         /**
2650          * Determines whether cascading protection sources have already been loaded from
2651          * the database.
2652          *
2653          * @param bool $getPages True to check if the pages are loaded, or false to check
2654          * if the status is loaded.
2655          * @return bool Whether or not the specified information has been loaded
2656          * @since 1.23
2657          */
2658         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2659                 return $getPages ? isset( $this->mCascadeSources ) : isset( $this->mHasCascadingRestrictions );
2660         }
2661
2662         /**
2663          * Cascading protection: Get the source of any cascading restrictions on this page.
2664          *
2665          * @param bool $getPages Whether or not to retrieve the actual pages
2666          *        that the restrictions have come from.
2667          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2668          *     have come, false for none, or true if such restrictions exist, but $getPages
2669          *     was not set.  The restriction array is an array of each type, each of which
2670          *     contains a array of unique groups.
2671          */
2672         public function getCascadeProtectionSources( $getPages = true ) {
2673                 global $wgContLang;
2674                 $pagerestrictions = array();
2675
2676                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2677                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2678                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2679                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2680                 }
2681
2682                 wfProfileIn( __METHOD__ );
2683
2684                 $dbr = wfGetDB( DB_SLAVE );
2685
2686                 if ( $this->getNamespace() == NS_FILE ) {
2687                         $tables = array( 'imagelinks', 'page_restrictions' );
2688                         $where_clauses = array(
2689                                 'il_to' => $this->getDBkey(),
2690                                 'il_from=pr_page',
2691                                 'pr_cascade' => 1
2692                         );
2693                 } else {
2694                         $tables = array( 'templatelinks', 'page_restrictions' );
2695                         $where_clauses = array(
2696                                 'tl_namespace' => $this->getNamespace(),
2697                                 'tl_title' => $this->getDBkey(),
2698                                 'tl_from=pr_page',
2699                                 'pr_cascade' => 1
2700                         );
2701                 }
2702
2703                 if ( $getPages ) {
2704                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2705                                 'pr_expiry', 'pr_type', 'pr_level' );
2706                         $where_clauses[] = 'page_id=pr_page';
2707                         $tables[] = 'page';
2708                 } else {
2709                         $cols = array( 'pr_expiry' );
2710                 }
2711
2712                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2713
2714                 $sources = $getPages ? array() : false;
2715                 $now = wfTimestampNow();
2716                 $purgeExpired = false;
2717
2718                 foreach ( $res as $row ) {
2719                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2720                         if ( $expiry > $now ) {
2721                                 if ( $getPages ) {
2722                                         $page_id = $row->pr_page;
2723                                         $page_ns = $row->page_namespace;
2724                                         $page_title = $row->page_title;
2725                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2726                                         # Add groups needed for each restriction type if its not already there
2727                                         # Make sure this restriction type still exists
2728
2729                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2730                                                 $pagerestrictions[$row->pr_type] = array();
2731                                         }
2732
2733                                         if (
2734                                                 isset( $pagerestrictions[$row->pr_type] )
2735                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2736                                         ) {
2737                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2738                                         }
2739                                 } else {
2740                                         $sources = true;
2741                                 }
2742                         } else {
2743                                 // Trigger lazy purge of expired restrictions from the db
2744                                 $purgeExpired = true;
2745                         }
2746                 }
2747                 if ( $purgeExpired ) {
2748                         Title::purgeExpiredRestrictions();
2749                 }
2750
2751                 if ( $getPages ) {
2752                         $this->mCascadeSources = $sources;
2753                         $this->mCascadingRestrictions = $pagerestrictions;
2754                 } else {
2755                         $this->mHasCascadingRestrictions = $sources;
2756                 }
2757
2758                 wfProfileOut( __METHOD__ );
2759                 return array( $sources, $pagerestrictions );
2760         }
2761
2762         /**
2763          * Accessor for mRestrictionsLoaded
2764          *
2765          * @return bool Whether or not the page's restrictions have already been
2766          * loaded from the database
2767          * @since 1.23
2768          */
2769         public function areRestrictionsLoaded() {
2770                 return $this->mRestrictionsLoaded;
2771         }
2772
2773         /**
2774          * Accessor/initialisation for mRestrictions
2775          *
2776          * @param string $action action that permission needs to be checked for
2777          * @return Array of Strings the array of groups allowed to edit this article
2778          */
2779         public function getRestrictions( $action ) {
2780                 if ( !$this->mRestrictionsLoaded ) {
2781                         $this->loadRestrictions();
2782                 }
2783                 return isset( $this->mRestrictions[$action] )
2784                                 ? $this->mRestrictions[$action]
2785                                 : array();
2786         }
2787
2788         /**
2789          * Accessor/initialisation for mRestrictions
2790          *
2791          * @return Array of Arrays of Strings the first level indexed by
2792          * action, the second level containing the names of the groups
2793          * allowed to perform each action
2794          * @since 1.23
2795          */
2796         public function getAllRestrictions() {
2797                 if ( !$this->mRestrictionsLoaded ) {
2798                         $this->loadRestrictions();
2799                 }
2800                 return $this->mRestrictions;
2801         }
2802
2803         /**
2804          * Get the expiry time for the restriction against a given action
2805          *
2806          * @param $action
2807          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2808          *     or not protected at all, or false if the action is not recognised.
2809          */
2810         public function getRestrictionExpiry( $action ) {
2811                 if ( !$this->mRestrictionsLoaded ) {
2812                         $this->loadRestrictions();
2813                 }
2814                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2815         }
2816
2817         /**
2818          * Returns cascading restrictions for the current article
2819          *
2820          * @return Boolean
2821          */
2822         function areRestrictionsCascading() {
2823                 if ( !$this->mRestrictionsLoaded ) {
2824                         $this->loadRestrictions();
2825                 }
2826
2827                 return $this->mCascadeRestriction;
2828         }
2829
2830         /**
2831          * Loads a string into mRestrictions array
2832          *
2833          * @param $res Resource restrictions as an SQL result.
2834          * @param string $oldFashionedRestrictions comma-separated list of page
2835          *        restrictions from page table (pre 1.10)
2836          */
2837         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2838                 $rows = array();
2839
2840                 foreach ( $res as $row ) {
2841                         $rows[] = $row;
2842                 }
2843
2844                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2845         }
2846
2847         /**
2848          * Compiles list of active page restrictions from both page table (pre 1.10)
2849          * and page_restrictions table for this existing page.
2850          * Public for usage by LiquidThreads.
2851          *
2852          * @param array $rows of db result objects
2853          * @param string $oldFashionedRestrictions comma-separated list of page
2854          *        restrictions from page table (pre 1.10)
2855          */
2856         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2857                 global $wgContLang;
2858                 $dbr = wfGetDB( DB_SLAVE );
2859
2860                 $restrictionTypes = $this->getRestrictionTypes();
2861
2862                 foreach ( $restrictionTypes as $type ) {
2863                         $this->mRestrictions[$type] = array();
2864                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2865                 }
2866
2867                 $this->mCascadeRestriction = false;
2868
2869                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2870
2871                 if ( $oldFashionedRestrictions === null ) {
2872                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2873                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2874                 }
2875
2876                 if ( $oldFashionedRestrictions != '' ) {
2877
2878                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2879                                 $temp = explode( '=', trim( $restrict ) );
2880                                 if ( count( $temp ) == 1 ) {
2881                                         // old old format should be treated as edit/move restriction
2882                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2883                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2884                                 } else {
2885                                         $restriction = trim( $temp[1] );
2886                                         if ( $restriction != '' ) { //some old entries are empty
2887                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2888                                         }
2889                                 }
2890                         }
2891
2892                         $this->mOldRestrictions = true;
2893
2894                 }
2895
2896                 if ( count( $rows ) ) {
2897                         # Current system - load second to make them override.
2898                         $now = wfTimestampNow();
2899                         $purgeExpired = false;
2900
2901                         # Cycle through all the restrictions.
2902                         foreach ( $rows as $row ) {
2903
2904                                 // Don't take care of restrictions types that aren't allowed
2905                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2906                                         continue;
2907                                 }
2908
2909                                 // This code should be refactored, now that it's being used more generally,
2910                                 // But I don't really see any harm in leaving it in Block for now -werdna
2911                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2912
2913                                 // Only apply the restrictions if they haven't expired!
2914                                 if ( !$expiry || $expiry > $now ) {
2915                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2916                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2917
2918                                         $this->mCascadeRestriction |= $row->pr_cascade;
2919                                 } else {
2920                                         // Trigger a lazy purge of expired restrictions
2921                                         $purgeExpired = true;
2922                                 }
2923                         }
2924
2925                         if ( $purgeExpired ) {
2926                                 Title::purgeExpiredRestrictions();
2927                         }
2928                 }
2929
2930                 $this->mRestrictionsLoaded = true;
2931         }
2932
2933         /**
2934          * Load restrictions from the page_restrictions table
2935          *
2936          * @param string $oldFashionedRestrictions comma-separated list of page
2937          *        restrictions from page table (pre 1.10)
2938          */
2939         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2940                 global $wgContLang;
2941                 if ( !$this->mRestrictionsLoaded ) {
2942                         if ( $this->exists() ) {
2943                                 $dbr = wfGetDB( DB_SLAVE );
2944
2945                                 $res = $dbr->select(
2946                                         'page_restrictions',
2947                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2948                                         array( 'pr_page' => $this->getArticleID() ),
2949                                         __METHOD__
2950                                 );
2951
2952                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2953                         } else {
2954                                 $title_protection = $this->getTitleProtection();
2955
2956                                 if ( $title_protection ) {
2957                                         $now = wfTimestampNow();
2958                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2959
2960                                         if ( !$expiry || $expiry > $now ) {
2961                                                 // Apply the restrictions
2962                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2963                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2964                                         } else { // Get rid of the old restrictions
2965                                                 Title::purgeExpiredRestrictions();
2966                                                 $this->mTitleProtection = false;
2967                                         }
2968                                 } else {
2969                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2970                                 }
2971                                 $this->mRestrictionsLoaded = true;
2972                         }
2973                 }
2974         }
2975
2976         /**
2977          * Flush the protection cache in this object and force reload from the database.
2978          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2979          */
2980         public function flushRestrictions() {
2981                 $this->mRestrictionsLoaded = false;
2982                 $this->mTitleProtection = null;
2983         }
2984
2985         /**
2986          * Purge expired restrictions from the page_restrictions table
2987          */
2988         static function purgeExpiredRestrictions() {
2989                 if ( wfReadOnly() ) {
2990                         return;
2991                 }
2992
2993                 $method = __METHOD__;
2994                 $dbw = wfGetDB( DB_MASTER );
2995                 $dbw->onTransactionIdle( function() use ( $dbw, $method ) {
2996                         $dbw->delete(
2997                                 'page_restrictions',
2998                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2999                                 $method
3000                         );
3001                         $dbw->delete(
3002                                 'protected_titles',
3003                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3004                                 $method
3005                         );
3006                 } );
3007         }
3008
3009         /**
3010          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3011          *
3012          * @return Bool
3013          */
3014         public function hasSubpages() {
3015                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3016                         # Duh
3017                         return false;
3018                 }
3019
3020                 # We dynamically add a member variable for the purpose of this method
3021                 # alone to cache the result.  There's no point in having it hanging
3022                 # around uninitialized in every Title object; therefore we only add it
3023                 # if needed and don't declare it statically.
3024                 if ( !isset( $this->mHasSubpages ) ) {
3025                         $this->mHasSubpages = false;
3026                         $subpages = $this->getSubpages( 1 );
3027                         if ( $subpages instanceof TitleArray ) {
3028                                 $this->mHasSubpages = (bool)$subpages->count();
3029                         }
3030                 }
3031
3032                 return $this->mHasSubpages;
3033         }
3034
3035         /**
3036          * Get all subpages of this page.
3037          *
3038          * @param int $limit maximum number of subpages to fetch; -1 for no limit
3039          * @return mixed TitleArray, or empty array if this page's namespace
3040          *  doesn't allow subpages
3041          */
3042         public function getSubpages( $limit = -1 ) {
3043                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3044                         return array();
3045                 }
3046
3047                 $dbr = wfGetDB( DB_SLAVE );
3048                 $conds['page_namespace'] = $this->getNamespace();
3049                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3050                 $options = array();
3051                 if ( $limit > -1 ) {
3052                         $options['LIMIT'] = $limit;
3053                 }
3054                 $this->mSubpages = TitleArray::newFromResult(
3055                         $dbr->select( 'page',
3056                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3057                                 $conds,
3058                                 __METHOD__,
3059                                 $options
3060                         )
3061                 );
3062                 return $this->mSubpages;
3063         }
3064
3065         /**
3066          * Is there a version of this page in the deletion archive?
3067          *
3068          * @return Int the number of archived revisions
3069          */
3070         public function isDeleted() {
3071                 if ( $this->getNamespace() < 0 ) {
3072                         $n = 0;
3073                 } else {
3074                         $dbr = wfGetDB( DB_SLAVE );
3075
3076                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3077                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3078                                 __METHOD__
3079                         );
3080                         if ( $this->getNamespace() == NS_FILE ) {
3081                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3082                                         array( 'fa_name' => $this->getDBkey() ),
3083                                         __METHOD__
3084                                 );
3085                         }
3086                 }
3087                 return (int)$n;
3088         }
3089
3090         /**
3091          * Is there a version of this page in the deletion archive?
3092          *
3093          * @return Boolean
3094          */
3095         public function isDeletedQuick() {
3096                 if ( $this->getNamespace() < 0 ) {
3097                         return false;
3098                 }
3099                 $dbr = wfGetDB( DB_SLAVE );
3100                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3101                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3102                         __METHOD__
3103                 );
3104                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3105                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3106                                 array( 'fa_name' => $this->getDBkey() ),
3107                                 __METHOD__
3108                         );
3109                 }
3110                 return $deleted;
3111         }
3112
3113         /**
3114          * Get the article ID for this Title from the link cache,
3115          * adding it if necessary
3116          *
3117          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select
3118          *  for update
3119          * @return Int the ID
3120          */
3121         public function getArticleID( $flags = 0 ) {
3122                 if ( $this->getNamespace() < 0 ) {
3123                         $this->mArticleID = 0;
3124                         return $this->mArticleID;
3125                 }
3126                 $linkCache = LinkCache::singleton();
3127                 if ( $flags & self::GAID_FOR_UPDATE ) {
3128                         $oldUpdate = $linkCache->forUpdate( true );
3129                         $linkCache->clearLink( $this );
3130                         $this->mArticleID = $linkCache->addLinkObj( $this );
3131                         $linkCache->forUpdate( $oldUpdate );
3132                 } else {
3133                         if ( -1 == $this->mArticleID ) {
3134                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3135                         }
3136                 }
3137                 return $this->mArticleID;
3138         }
3139
3140         /**
3141          * Is this an article that is a redirect page?
3142          * Uses link cache, adding it if necessary
3143          *
3144          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3145          * @return Bool
3146          */
3147         public function isRedirect( $flags = 0 ) {
3148                 if ( !is_null( $this->mRedirect ) ) {
3149                         return $this->mRedirect;
3150                 }
3151                 # Calling getArticleID() loads the field from cache as needed
3152                 if ( !$this->getArticleID( $flags ) ) {
3153                         $this->mRedirect = false;
3154                         return $this->mRedirect;
3155                 }
3156
3157                 $linkCache = LinkCache::singleton();
3158                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3159                 if ( $cached === null ) {
3160                         # Trust LinkCache's state over our own
3161                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3162                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3163                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3164                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3165                         # LinkCache to refresh its data from the master.
3166                         $this->mRedirect = false;
3167                         return $this->mRedirect;
3168                 }
3169
3170                 $this->mRedirect = (bool)$cached;
3171
3172                 return $this->mRedirect;
3173         }
3174
3175         /**
3176          * What is the length of this page?
3177          * Uses link cache, adding it if necessary
3178          *
3179          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3180          * @return Int
3181          */
3182         public function getLength( $flags = 0 ) {
3183                 if ( $this->mLength != -1 ) {
3184                         return $this->mLength;
3185                 }
3186                 # Calling getArticleID() loads the field from cache as needed
3187                 if ( !$this->getArticleID( $flags ) ) {
3188                         $this->mLength = 0;
3189                         return $this->mLength;
3190                 }
3191                 $linkCache = LinkCache::singleton();
3192                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3193                 if ( $cached === null ) {
3194                         # Trust LinkCache's state over our own, as for isRedirect()
3195                         $this->mLength = 0;
3196                         return $this->mLength;
3197                 }
3198
3199                 $this->mLength = intval( $cached );
3200
3201                 return $this->mLength;
3202         }
3203
3204         /**
3205          * What is the page_latest field for this page?
3206          *
3207          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3208          * @return Int or 0 if the page doesn't exist
3209          */
3210         public function getLatestRevID( $flags = 0 ) {
3211                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3212                         return intval( $this->mLatestID );
3213                 }
3214                 # Calling getArticleID() loads the field from cache as needed
3215                 if ( !$this->getArticleID( $flags ) ) {
3216                         $this->mLatestID = 0;
3217                         return $this->mLatestID;
3218                 }
3219                 $linkCache = LinkCache::singleton();
3220                 $linkCache->addLinkObj( $this );
3221                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3222                 if ( $cached === null ) {
3223                         # Trust LinkCache's state over our own, as for isRedirect()
3224                         $this->mLatestID = 0;
3225                         return $this->mLatestID;
3226                 }
3227
3228                 $this->mLatestID = intval( $cached );
3229
3230                 return $this->mLatestID;
3231         }
3232
3233         /**
3234          * This clears some fields in this object, and clears any associated
3235          * keys in the "bad links" section of the link cache.
3236          *
3237          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3238          * loading of the new page_id. It's also called from
3239          * WikiPage::doDeleteArticleReal()
3240          *
3241          * @param int $newid the new Article ID
3242          */
3243         public function resetArticleID( $newid ) {
3244                 $linkCache = LinkCache::singleton();
3245                 $linkCache->clearLink( $this );
3246
3247                 if ( $newid === false ) {
3248                         $this->mArticleID = -1;
3249                 } else {
3250                         $this->mArticleID = intval( $newid );
3251                 }
3252                 $this->mRestrictionsLoaded = false;
3253                 $this->mRestrictions = array();
3254                 $this->mRedirect = null;
3255                 $this->mLength = -1;
3256                 $this->mLatestID = false;
3257                 $this->mContentModel = false;
3258                 $this->mEstimateRevisions = null;
3259                 $this->mPageLanguage = false;
3260         }
3261
3262         /**
3263          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3264          *
3265          * @param string $text containing title to capitalize
3266          * @param int $ns namespace index, defaults to NS_MAIN
3267          * @return String containing capitalized title
3268          */
3269         public static function capitalize( $text, $ns = NS_MAIN ) {
3270                 global $wgContLang;
3271
3272                 if ( MWNamespace::isCapitalized( $ns ) ) {
3273                         return $wgContLang->ucfirst( $text );
3274                 } else {
3275                         return $text;
3276                 }
3277         }
3278
3279         /**
3280          * Secure and split - main initialisation function for this object
3281          *
3282          * Assumes that mDbkeyform has been set, and is urldecoded
3283          * and uses underscores, but not otherwise munged.  This function
3284          * removes illegal characters, splits off the interwiki and
3285          * namespace prefixes, sets the other forms, and canonicalizes
3286          * everything.
3287          *
3288          * @return Bool true on success
3289          */
3290         private function secureAndSplit() {
3291                 # Initialisation
3292                 $this->mInterwiki = '';
3293                 $this->mFragment = '';
3294                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3295
3296                 $dbkey = $this->mDbkeyform;
3297
3298                 try {
3299                         // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3300                         //        the parsing code with Title, while avoiding massive refactoring.
3301                         // @todo: get rid of secureAndSplit, refactor parsing code.
3302                         $parser = $this->getTitleParser();
3303                         $parts = $parser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3304                 } catch ( MalformedTitleException $ex ) {
3305                         return false;
3306                 }
3307
3308                 # Fill fields
3309                 $this->setFragment( '#' . $parts['fragment'] );
3310                 $this->mInterwiki = $parts['interwiki'];
3311                 $this->mNamespace = $parts['namespace'];
3312                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3313
3314                 $this->mDbkeyform = $parts['dbkey'];
3315                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3316                 $this->mTextform = str_replace( '_', ' ', $this->mDbkeyform );
3317
3318                 # We already know that some pages won't be in the database!
3319                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3320                         $this->mArticleID = 0;
3321                 }
3322
3323                 return true;
3324         }
3325
3326         /**
3327          * Get an array of Title objects linking to this Title
3328          * Also stores the IDs in the link cache.
3329          *
3330          * WARNING: do not use this function on arbitrary user-supplied titles!
3331          * On heavily-used templates it will max out the memory.
3332          *
3333          * @param array $options may be FOR UPDATE
3334          * @param string $table table name
3335          * @param string $prefix fields prefix
3336          * @return Array of Title objects linking here
3337          */
3338         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3339                 if ( count( $options ) > 0 ) {
3340                         $db = wfGetDB( DB_MASTER );
3341                 } else {
3342                         $db = wfGetDB( DB_SLAVE );
3343                 }
3344
3345                 $res = $db->select(
3346                         array( 'page', $table ),
3347                         self::getSelectFields(),
3348                         array(
3349                                 "{$prefix}_from=page_id",
3350                                 "{$prefix}_namespace" => $this->getNamespace(),
3351                                 "{$prefix}_title" => $this->getDBkey() ),
3352                         __METHOD__,
3353                         $options
3354                 );
3355
3356                 $retVal = array();
3357                 if ( $res->numRows() ) {
3358                         $linkCache = LinkCache::singleton();
3359                         foreach ( $res as $row ) {
3360                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3361                                 if ( $titleObj ) {
3362                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3363                                         $retVal[] = $titleObj;
3364                                 }
3365                         }
3366                 }
3367                 return $retVal;
3368         }
3369
3370         /**
3371          * Get an array of Title objects using this Title as a template
3372          * Also stores the IDs in the link cache.
3373          *
3374          * WARNING: do not use this function on arbitrary user-supplied titles!
3375          * On heavily-used templates it will max out the memory.
3376          *
3377          * @param array $options may be FOR UPDATE
3378          * @return Array of Title the Title objects linking here
3379          */
3380         public function getTemplateLinksTo( $options = array() ) {
3381                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3382         }
3383
3384         /**
3385          * Get an array of Title objects linked from this Title
3386          * Also stores the IDs in the link cache.
3387          *
3388          * WARNING: do not use this function on arbitrary user-supplied titles!
3389          * On heavily-used templates it will max out the memory.
3390          *
3391          * @param array $options may be FOR UPDATE
3392          * @param string $table table name
3393          * @param string $prefix fields prefix
3394          * @return Array of Title objects linking here
3395          */
3396         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3397                 global $wgContentHandlerUseDB;
3398
3399                 $id = $this->getArticleID();
3400
3401                 # If the page doesn't exist; there can't be any link from this page
3402                 if ( !$id ) {
3403                         return array();
3404                 }
3405
3406                 if ( count( $options ) > 0 ) {
3407                         $db = wfGetDB( DB_MASTER );
3408                 } else {
3409                         $db = wfGetDB( DB_SLAVE );
3410                 }
3411
3412                 $namespaceFiled = "{$prefix}_namespace";
3413                 $titleField = "{$prefix}_title";
3414
3415                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3416                 if ( $wgContentHandlerUseDB ) {
3417                         $fields[] = 'page_content_model';
3418                 }
3419
3420                 $res = $db->select(
3421                         array( $table, 'page' ),
3422                         $fields,
3423                         array( "{$prefix}_from" => $id ),
3424                         __METHOD__,
3425                         $options,
3426                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3427                 );
3428
3429                 $retVal = array();
3430                 if ( $res->numRows() ) {
3431                         $linkCache = LinkCache::singleton();
3432                         foreach ( $res as $row ) {
3433                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3434                                 if ( $titleObj ) {
3435                                         if ( $row->page_id ) {
3436                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3437                                         } else {
3438                                                 $linkCache->addBadLinkObj( $titleObj );
3439                                         }
3440                                         $retVal[] = $titleObj;
3441                                 }
3442                         }
3443                 }
3444                 return $retVal;
3445         }
3446
3447         /**
3448          * Get an array of Title objects used on this Title as a template
3449          * Also stores the IDs in the link cache.
3450          *
3451          * WARNING: do not use this function on arbitrary user-supplied titles!
3452          * On heavily-used templates it will max out the memory.
3453          *
3454          * @param array $options may be FOR UPDATE
3455          * @return Array of Title the Title objects used here
3456          */
3457         public function getTemplateLinksFrom( $options = array() ) {
3458                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3459         }
3460
3461         /**
3462          * Get an array of Title objects referring to non-existent articles linked from this page
3463          *
3464          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3465          * @return Array of Title the Title objects
3466          */
3467         public function getBrokenLinksFrom() {
3468                 if ( $this->getArticleID() == 0 ) {
3469                         # All links from article ID 0 are false positives
3470                         return array();
3471                 }
3472
3473                 $dbr = wfGetDB( DB_SLAVE );
3474                 $res = $dbr->select(
3475                         array( 'page', 'pagelinks' ),
3476                         array( 'pl_namespace', 'pl_title' ),
3477                         array(
3478                                 'pl_from' => $this->getArticleID(),
3479                                 'page_namespace IS NULL'
3480                         ),
3481                         __METHOD__, array(),
3482                         array(
3483                                 'page' => array(
3484                                         'LEFT JOIN',
3485                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3486                                 )
3487                         )
3488                 );
3489
3490                 $retVal = array();
3491                 foreach ( $res as $row ) {
3492                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3493                 }
3494                 return $retVal;
3495         }
3496
3497         /**
3498          * Get a list of URLs to purge from the Squid cache when this
3499          * page changes
3500          *
3501          * @return Array of String the URLs
3502          */
3503         public function getSquidURLs() {
3504                 $urls = array(
3505                         $this->getInternalURL(),
3506                         $this->getInternalURL( 'action=history' )
3507                 );
3508
3509                 $pageLang = $this->getPageLanguage();
3510                 if ( $pageLang->hasVariants() ) {
3511                         $variants = $pageLang->getVariants();
3512                         foreach ( $variants as $vCode ) {
3513                                 $urls[] = $this->getInternalURL( '', $vCode );
3514                         }
3515                 }
3516
3517                 // If we are looking at a css/js user subpage, purge the action=raw.
3518                 if ( $this->isJsSubpage() ) {
3519                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3520                 } elseif ( $this->isCssSubpage() ) {
3521                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3522                 }
3523
3524                 wfRunHooks( 'TitleSquidURLs', array( $this, &$urls ) );
3525                 return $urls;
3526         }
3527
3528         /**
3529          * Purge all applicable Squid URLs
3530          */
3531         public function purgeSquid() {
3532                 global $wgUseSquid;
3533                 if ( $wgUseSquid ) {
3534                         $urls = $this->getSquidURLs();
3535                         $u = new SquidUpdate( $urls );
3536                         $u->doUpdate();
3537                 }
3538         }
3539
3540         /**
3541          * Move this page without authentication
3542          *
3543          * @param $nt Title the new page Title
3544          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3545          */
3546         public function moveNoAuth( &$nt ) {
3547                 return $this->moveTo( $nt, false );
3548         }
3549
3550         /**
3551          * Check whether a given move operation would be valid.
3552          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3553          *
3554          * @param $nt Title the new title
3555          * @param bool $auth indicates whether $wgUser's permissions
3556          *  should be checked
3557          * @param string $reason is the log summary of the move, used for spam checking
3558          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3559          */
3560         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3561                 global $wgUser, $wgContentHandlerUseDB;
3562
3563                 $errors = array();
3564                 if ( !$nt ) {
3565                         // Normally we'd add this to $errors, but we'll get
3566                         // lots of syntax errors if $nt is not an object
3567                         return array( array( 'badtitletext' ) );
3568                 }
3569                 if ( $this->equals( $nt ) ) {
3570                         $errors[] = array( 'selfmove' );
3571                 }
3572                 if ( !$this->isMovable() ) {
3573                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3574                 }
3575                 if ( $nt->isExternal() ) {
3576                         $errors[] = array( 'immobile-target-namespace-iw' );
3577                 }
3578                 if ( !$nt->isMovable() ) {
3579                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3580                 }
3581
3582                 $oldid = $this->getArticleID();
3583                 $newid = $nt->getArticleID();
3584
3585                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3586                         $errors[] = array( 'articleexists' );
3587                 }
3588                 if (
3589                         ( $this->getDBkey() == '' ) ||
3590                         ( !$oldid ) ||
3591                         ( $nt->getDBkey() == '' )
3592                 ) {
3593                         $errors[] = array( 'badarticleerror' );
3594                 }
3595
3596                 // Content model checks
3597                 if ( !$wgContentHandlerUseDB &&
3598                                 $this->getContentModel() !== $nt->getContentModel() ) {
3599                         // can't move a page if that would change the page's content model
3600                         $errors[] = array(
3601                                 'bad-target-model',
3602                                 ContentHandler::getLocalizedName( $this->getContentModel() ),
3603                                 ContentHandler::getLocalizedName( $nt->getContentModel() )
3604                         );
3605                 }
3606
3607                 // Image-specific checks
3608                 if ( $this->getNamespace() == NS_FILE ) {
3609                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3610                 }
3611
3612                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3613                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3614                 }
3615
3616                 if ( $auth ) {
3617                         $errors = wfMergeErrorArrays( $errors,
3618                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3619                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3620                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3621                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3622                 }
3623
3624                 $match = EditPage::matchSummarySpamRegex( $reason );
3625                 if ( $match !== false ) {
3626                         // This is kind of lame, won't display nice
3627                         $errors[] = array( 'spamprotectiontext' );
3628                 }
3629
3630                 $err = null;
3631                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3632                         $errors[] = array( 'hookaborted', $err );
3633                 }
3634
3635                 # The move is allowed only if (1) the target doesn't exist, or
3636                 # (2) the target is a redirect to the source, and has no history
3637                 # (so we can undo bad moves right after they're done).
3638
3639                 if ( 0 != $newid ) { # Target exists; check for validity
3640                         if ( !$this->isValidMoveTarget( $nt ) ) {
3641                                 $errors[] = array( 'articleexists' );
3642                         }
3643                 } else {
3644                         $tp = $nt->getTitleProtection();
3645                         $right = $tp['pt_create_perm'];
3646                         if ( $right == 'sysop' ) {
3647                                 $right = 'editprotected'; // B/C
3648                         }
3649                         if ( $right == 'autoconfirmed' ) {
3650                                 $right = 'editsemiprotected'; // B/C
3651                         }
3652                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3653                                 $errors[] = array( 'cantmove-titleprotected' );
3654                         }
3655                 }
3656                 if ( empty( $errors ) ) {
3657                         return true;
3658                 }
3659                 return $errors;
3660         }
3661
3662         /**
3663          * Check if the requested move target is a valid file move target
3664          * @param Title $nt Target title
3665          * @return array List of errors
3666          */
3667         protected function validateFileMoveOperation( $nt ) {
3668                 global $wgUser;
3669
3670                 $errors = array();
3671
3672                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3673
3674                 $file = wfLocalFile( $this );
3675                 if ( $file->exists() ) {
3676                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3677                                 $errors[] = array( 'imageinvalidfilename' );
3678                         }
3679                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3680                                 $errors[] = array( 'imagetypemismatch' );
3681                         }
3682                 }
3683
3684                 if ( $nt->getNamespace() != NS_FILE ) {
3685                         $errors[] = array( 'imagenocrossnamespace' );
3686                         // From here we want to do checks on a file object, so if we can't
3687                         // create one, we must return.
3688                         return $errors;
3689                 }
3690
3691                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3692
3693                 $destFile = wfLocalFile( $nt );
3694                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3695                         $errors[] = array( 'file-exists-sharedrepo' );
3696                 }
3697
3698                 return $errors;
3699         }
3700
3701         /**
3702          * Move a title to a new location
3703          *
3704          * @param $nt Title the new title
3705          * @param bool $auth indicates whether $wgUser's permissions
3706          *  should be checked
3707          * @param string $reason the reason for the move
3708          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3709          *  Ignored if the user doesn't have the suppressredirect right.
3710          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3711          */
3712         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3713                 global $wgUser;
3714                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3715                 if ( is_array( $err ) ) {
3716                         // Auto-block user's IP if the account was "hard" blocked
3717                         $wgUser->spreadAnyEditBlock();
3718                         return $err;
3719                 }
3720                 // Check suppressredirect permission
3721                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3722                         $createRedirect = true;
3723                 }
3724
3725                 wfRunHooks( 'TitleMove', array( $this, $nt, $wgUser ) );
3726
3727                 // If it is a file, move it first.
3728                 // It is done before all other moving stuff is done because it's hard to revert.
3729                 $dbw = wfGetDB( DB_MASTER );
3730                 if ( $this->getNamespace() == NS_FILE ) {
3731                         $file = wfLocalFile( $this );
3732                         if ( $file->exists() ) {
3733                                 $status = $file->move( $nt );
3734                                 if ( !$status->isOk() ) {
3735                                         return $status->getErrorsArray();
3736                                 }
3737                         }
3738                         // Clear RepoGroup process cache
3739                         RepoGroup::singleton()->clearCache( $this );
3740                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3741                 }
3742
3743                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3744                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3745                 $protected = $this->isProtected();
3746
3747                 // Do the actual move
3748                 $this->moveToInternal( $nt, $reason, $createRedirect );
3749
3750                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3751                 // cl_timestamp, which may disturb time-based lists on some sites.
3752                 $prefixes = $dbw->select(
3753                         'categorylinks',
3754                         array( 'cl_sortkey_prefix', 'cl_to' ),
3755                         array( 'cl_from' => $pageid ),
3756                         __METHOD__
3757                 );
3758                 foreach ( $prefixes as $prefixRow ) {
3759                         $prefix = $prefixRow->cl_sortkey_prefix;
3760                         $catTo = $prefixRow->cl_to;
3761                         $dbw->update( 'categorylinks',
3762                                 array(
3763                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3764                                                 $nt->getCategorySortkey( $prefix ) ),
3765                                         'cl_timestamp=cl_timestamp' ),
3766                                 array(
3767                                         'cl_from' => $pageid,
3768                                         'cl_to' => $catTo ),
3769                                 __METHOD__
3770                         );
3771                 }
3772
3773                 $redirid = $this->getArticleID();
3774
3775                 if ( $protected ) {
3776                         # Protect the redirect title as the title used to be...
3777                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3778                                 array(
3779                                         'pr_page' => $redirid,
3780                                         'pr_type' => 'pr_type',
3781                                         'pr_level' => 'pr_level',
3782                                         'pr_cascade' => 'pr_cascade',
3783                                         'pr_user' => 'pr_user',
3784                                         'pr_expiry' => 'pr_expiry'
3785                                 ),
3786                                 array( 'pr_page' => $pageid ),
3787                                 __METHOD__,
3788                                 array( 'IGNORE' )
3789                         );
3790                         # Update the protection log
3791                         $log = new LogPage( 'protect' );
3792                         $comment = wfMessage(
3793                                 'prot_1movedto2',
3794                                 $this->getPrefixedText(),
3795                                 $nt->getPrefixedText()
3796                         )->inContentLanguage()->text();
3797                         if ( $reason ) {
3798                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3799                         }
3800                         // @todo FIXME: $params?
3801                         $logId = $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ), $wgUser );
3802
3803                         // reread inserted pr_ids for log relation
3804                         $insertedPrIds = $dbw->select(
3805                                 'page_restrictions',
3806                                 'pr_id',
3807                                 array( 'pr_page' => $redirid ),
3808                                 __METHOD__
3809                         );
3810                         $logRelationsValues = array();
3811                         foreach ( $insertedPrIds as $prid ) {
3812                                 $logRelationsValues[] = $prid->pr_id;
3813                         }
3814                         $log->addRelations( 'pr_id', $logRelationsValues, $logId );
3815                 }
3816
3817                 # Update watchlists
3818                 $oldnamespace = MWNamespace::getSubject( $this->getNamespace() );
3819                 $newnamespace = MWNamespace::getSubject( $nt->getNamespace() );
3820                 $oldtitle = $this->getDBkey();
3821                 $newtitle = $nt->getDBkey();
3822
3823                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3824                         WatchedItem::duplicateEntries( $this, $nt );
3825                 }
3826
3827                 $dbw->commit( __METHOD__ );
3828
3829                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid, $reason ) );
3830                 return true;
3831         }
3832
3833         /**
3834          * Move page to a title which is either a redirect to the
3835          * source page or nonexistent
3836          *
3837          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3838          * @param string $reason The reason for the move
3839          * @param bool $createRedirect Whether to leave a redirect at the old title. Does not check
3840          *   if the user has the suppressredirect right
3841          * @throws MWException
3842          */
3843         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3844                 global $wgUser, $wgContLang;
3845
3846                 if ( $nt->exists() ) {
3847                         $moveOverRedirect = true;
3848                         $logType = 'move_redir';
3849                 } else {
3850                         $moveOverRedirect = false;
3851                         $logType = 'move';
3852                 }
3853
3854                 if ( $createRedirect ) {
3855                         $contentHandler = ContentHandler::getForTitle( $this );
3856                         $redirectContent = $contentHandler->makeRedirectContent( $nt,
3857                                 wfMessage( 'move-redirect-text' )->inContentLanguage()->plain() );
3858
3859                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3860                 } else {
3861                         $redirectContent = null;
3862                 }
3863
3864                 $logEntry = new ManualLogEntry( 'move', $logType );
3865                 $logEntry->setPerformer( $wgUser );
3866                 $logEntry->setTarget( $this );
3867                 $logEntry->setComment( $reason );
3868                 $logEntry->setParameters( array(
3869                         '4::target' => $nt->getPrefixedText(),
3870                         '5::noredir' => $redirectContent ? '0': '1',
3871                 ) );
3872
3873                 $formatter = LogFormatter::newFromEntry( $logEntry );
3874                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3875                 $comment = $formatter->getPlainActionText();
3876                 if ( $reason ) {
3877                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3878                 }
3879                 # Truncate for whole multibyte characters.
3880                 $comment = $wgContLang->truncate( $comment, 255 );
3881
3882                 $oldid = $this->getArticleID();
3883
3884                 $dbw = wfGetDB( DB_MASTER );
3885
3886                 $newpage = WikiPage::factory( $nt );
3887
3888                 if ( $moveOverRedirect ) {
3889                         $newid = $nt->getArticleID();
3890                         $newcontent = $newpage->getContent();
3891
3892                         # Delete the old redirect. We don't save it to history since
3893                         # by definition if we've got here it's rather uninteresting.
3894                         # We have to remove it so that the next step doesn't trigger
3895                         # a conflict on the unique namespace+title index...
3896                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3897
3898                         $newpage->doDeleteUpdates( $newid, $newcontent );
3899                 }
3900
3901                 # Save a null revision in the page's history notifying of the move
3902                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3903                 if ( !is_object( $nullRevision ) ) {
3904                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3905                 }
3906
3907                 $nullRevision->insertOn( $dbw );
3908
3909                 # Change the name of the target page:
3910                 $dbw->update( 'page',
3911                         /* SET */ array(
3912                                 'page_namespace' => $nt->getNamespace(),
3913                                 'page_title' => $nt->getDBkey(),
3914                         ),
3915                         /* WHERE */ array( 'page_id' => $oldid ),
3916                         __METHOD__
3917                 );
3918
3919                 // clean up the old title before reset article id - bug 45348
3920                 if ( !$redirectContent ) {
3921                         WikiPage::onArticleDelete( $this );
3922                 }
3923
3924                 $this->resetArticleID( 0 ); // 0 == non existing
3925                 $nt->resetArticleID( $oldid );
3926                 $newpage->loadPageData( WikiPage::READ_LOCKING ); // bug 46397
3927
3928                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3929
3930                 wfRunHooks( 'NewRevisionFromEditComplete',
3931                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3932
3933                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3934
3935                 if ( !$moveOverRedirect ) {
3936                         WikiPage::onArticleCreate( $nt );
3937                 }
3938
3939                 # Recreate the redirect, this time in the other direction.
3940                 if ( $redirectContent ) {
3941                         $redirectArticle = WikiPage::factory( $this );
3942                         $redirectArticle->loadFromRow( false, WikiPage::READ_LOCKING ); // bug 46397
3943                         $newid = $redirectArticle->insertOn( $dbw );
3944                         if ( $newid ) { // sanity
3945                                 $this->resetArticleID( $newid );
3946                                 $redirectRevision = new Revision( array(
3947                                         'title' => $this, // for determining the default content model
3948                                         'page' => $newid,
3949                                         'comment' => $comment,
3950                                         'content' => $redirectContent ) );
3951                                 $redirectRevision->insertOn( $dbw );
3952                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3953
3954                                 wfRunHooks( 'NewRevisionFromEditComplete',
3955                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3956
3957                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3958                         }
3959                 }
3960
3961                 # Log the move
3962                 $logid = $logEntry->insert();
3963                 $logEntry->publish( $logid );
3964         }
3965
3966         /**
3967          * Move this page's subpages to be subpages of $nt
3968          *
3969          * @param $nt Title Move target
3970          * @param bool $auth Whether $wgUser's permissions should be checked
3971          * @param string $reason The reason for the move
3972          * @param bool $createRedirect Whether to create redirects from the old subpages to
3973          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3974          * @return mixed array with old page titles as keys, and strings (new page titles) or
3975          *     arrays (errors) as values, or an error array with numeric indices if no pages
3976          *     were moved
3977          */
3978         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3979                 global $wgMaximumMovedPages;
3980                 // Check permissions
3981                 if ( !$this->userCan( 'move-subpages' ) ) {
3982                         return array( 'cant-move-subpages' );
3983                 }
3984                 // Do the source and target namespaces support subpages?
3985                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3986                         return array( 'namespace-nosubpages',
3987                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3988                 }
3989                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3990                         return array( 'namespace-nosubpages',
3991                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3992                 }
3993
3994                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3995                 $retval = array();
3996                 $count = 0;
3997                 foreach ( $subpages as $oldSubpage ) {
3998                         $count++;
3999                         if ( $count > $wgMaximumMovedPages ) {
4000                                 $retval[$oldSubpage->getPrefixedText()] =
4001                                                 array( 'movepage-max-pages',
4002                                                         $wgMaximumMovedPages );
4003                                 break;
4004                         }
4005
4006                         // We don't know whether this function was called before
4007                         // or after moving the root page, so check both
4008                         // $this and $nt
4009                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
4010                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
4011                         ) {
4012                                 // When moving a page to a subpage of itself,
4013                                 // don't move it twice
4014                                 continue;
4015                         }
4016                         $newPageName = preg_replace(
4017                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
4018                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
4019                                         $oldSubpage->getDBkey() );
4020                         if ( $oldSubpage->isTalkPage() ) {
4021                                 $newNs = $nt->getTalkPage()->getNamespace();
4022                         } else {
4023                                 $newNs = $nt->getSubjectPage()->getNamespace();
4024                         }
4025                         # Bug 14385: we need makeTitleSafe because the new page names may
4026                         # be longer than 255 characters.
4027                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
4028
4029                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
4030                         if ( $success === true ) {
4031                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
4032                         } else {
4033                                 $retval[$oldSubpage->getPrefixedText()] = $success;
4034                         }
4035                 }
4036                 return $retval;
4037         }
4038
4039         /**
4040          * Checks if this page is just a one-rev redirect.
4041          * Adds lock, so don't use just for light purposes.
4042          *
4043          * @return Bool
4044          */
4045         public function isSingleRevRedirect() {
4046                 global $wgContentHandlerUseDB;
4047
4048                 $dbw = wfGetDB( DB_MASTER );
4049
4050                 # Is it a redirect?
4051                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
4052                 if ( $wgContentHandlerUseDB ) {
4053                         $fields[] = 'page_content_model';
4054                 }
4055
4056                 $row = $dbw->selectRow( 'page',
4057                         $fields,
4058                         $this->pageCond(),
4059                         __METHOD__,
4060                         array( 'FOR UPDATE' )
4061                 );
4062                 # Cache some fields we may want
4063                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
4064                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
4065                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
4066                 $this->mContentModel = $row && isset( $row->page_content_model ) ? strval( $row->page_content_model ) : false;
4067                 if ( !$this->mRedirect ) {
4068                         return false;
4069                 }
4070                 # Does the article have a history?
4071                 $row = $dbw->selectField( array( 'page', 'revision' ),
4072                         'rev_id',
4073                         array( 'page_namespace' => $this->getNamespace(),
4074                                 'page_title' => $this->getDBkey(),
4075                                 'page_id=rev_page',
4076                                 'page_latest != rev_id'
4077                         ),
4078                         __METHOD__,
4079                         array( 'FOR UPDATE' )
4080                 );
4081                 # Return true if there was no history
4082                 return ( $row === false );
4083         }
4084
4085         /**
4086          * Checks if $this can be moved to a given Title
4087          * - Selects for update, so don't call it unless you mean business
4088          *
4089          * @param $nt Title the new title to check
4090          * @return Bool
4091          */
4092         public function isValidMoveTarget( $nt ) {
4093                 # Is it an existing file?
4094                 if ( $nt->getNamespace() == NS_FILE ) {
4095                         $file = wfLocalFile( $nt );
4096                         if ( $file->exists() ) {
4097                                 wfDebug( __METHOD__ . ": file exists\n" );
4098                                 return false;
4099                         }
4100                 }
4101                 # Is it a redirect with no history?
4102                 if ( !$nt->isSingleRevRedirect() ) {
4103                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
4104                         return false;
4105                 }
4106                 # Get the article text
4107                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
4108                 if ( !is_object( $rev ) ) {
4109                         return false;
4110                 }
4111                 $content = $rev->getContent();
4112                 # Does the redirect point to the source?
4113                 # Or is it a broken self-redirect, usually caused by namespace collisions?
4114                 $redirTitle = $content ? $content->getRedirectTarget() : null;
4115
4116                 if ( $redirTitle ) {
4117                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
4118                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
4119                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
4120                                 return false;
4121                         } else {
4122                                 return true;
4123                         }
4124                 } else {
4125                         # Fail safe (not a redirect after all. strange.)
4126                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
4127                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
4128                         return false;
4129                 }
4130         }
4131
4132         /**
4133          * Get categories to which this Title belongs and return an array of
4134          * categories' names.
4135          *
4136          * @return Array of parents in the form:
4137          *        $parent => $currentarticle
4138          */
4139         public function getParentCategories() {
4140                 global $wgContLang;
4141
4142                 $data = array();
4143
4144                 $titleKey = $this->getArticleID();
4145
4146                 if ( $titleKey === 0 ) {
4147                         return $data;
4148                 }
4149
4150                 $dbr = wfGetDB( DB_SLAVE );
4151
4152                 $res = $dbr->select(
4153                         'categorylinks',
4154                         'cl_to',
4155                         array( 'cl_from' => $titleKey ),
4156                         __METHOD__
4157                 );
4158
4159                 if ( $res->numRows() > 0 ) {
4160                         foreach ( $res as $row ) {
4161                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
4162                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4163                         }
4164                 }
4165                 return $data;
4166         }
4167
4168         /**
4169          * Get a tree of parent categories
4170          *
4171          * @param array $children with the children in the keys, to check for circular refs
4172          * @return Array Tree of parent categories
4173          */
4174         public function getParentCategoryTree( $children = array() ) {
4175                 $stack = array();
4176                 $parents = $this->getParentCategories();
4177
4178                 if ( $parents ) {
4179                         foreach ( $parents as $parent => $current ) {
4180                                 if ( array_key_exists( $parent, $children ) ) {
4181                                         # Circular reference
4182                                         $stack[$parent] = array();
4183                                 } else {
4184                                         $nt = Title::newFromText( $parent );
4185                                         if ( $nt ) {
4186                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4187                                         }
4188                                 }
4189                         }
4190                 }
4191
4192                 return $stack;
4193         }
4194
4195         /**
4196          * Get an associative array for selecting this title from
4197          * the "page" table
4198          *
4199          * @return Array suitable for the $where parameter of DB::select()
4200          */
4201         public function pageCond() {
4202                 if ( $this->mArticleID > 0 ) {
4203                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4204                         return array( 'page_id' => $this->mArticleID );
4205                 } else {
4206                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4207                 }
4208         }
4209
4210         /**
4211          * Get the revision ID of the previous revision
4212          *
4213          * @param int $revId Revision ID. Get the revision that was before this one.
4214          * @param int $flags Title::GAID_FOR_UPDATE
4215          * @return Int|Bool Old revision ID, or FALSE if none exists
4216          */
4217         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4218                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4219                 $revId = $db->selectField( 'revision', 'rev_id',
4220                         array(
4221                                 'rev_page' => $this->getArticleID( $flags ),
4222                                 'rev_id < ' . intval( $revId )
4223                         ),
4224                         __METHOD__,
4225                         array( 'ORDER BY' => 'rev_id DESC' )
4226                 );
4227
4228                 if ( $revId === false ) {
4229                         return false;
4230                 } else {
4231                         return intval( $revId );
4232                 }
4233         }
4234
4235         /**
4236          * Get the revision ID of the next revision
4237          *
4238          * @param int $revId Revision ID. Get the revision that was after this one.
4239          * @param int $flags Title::GAID_FOR_UPDATE
4240          * @return Int|Bool Next revision ID, or FALSE if none exists
4241          */
4242         public function getNextRevisionID( $revId, $flags = 0 ) {
4243                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4244                 $revId = $db->selectField( 'revision', 'rev_id',
4245                         array(
4246                                 'rev_page' => $this->getArticleID( $flags ),
4247                                 'rev_id > ' . intval( $revId )
4248                         ),
4249                         __METHOD__,
4250                         array( 'ORDER BY' => 'rev_id' )
4251                 );
4252
4253                 if ( $revId === false ) {
4254                         return false;
4255                 } else {
4256                         return intval( $revId );
4257                 }
4258         }
4259
4260         /**
4261          * Get the first revision of the page
4262          *
4263          * @param int $flags Title::GAID_FOR_UPDATE
4264          * @return Revision|Null if page doesn't exist
4265          */
4266         public function getFirstRevision( $flags = 0 ) {
4267                 $pageId = $this->getArticleID( $flags );
4268                 if ( $pageId ) {
4269                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4270                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4271                                 array( 'rev_page' => $pageId ),
4272                                 __METHOD__,
4273                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4274                         );
4275                         if ( $row ) {
4276                                 return new Revision( $row );
4277                         }
4278                 }
4279                 return null;
4280         }
4281
4282         /**
4283          * Get the oldest revision timestamp of this page
4284          *
4285          * @param int $flags Title::GAID_FOR_UPDATE
4286          * @return String: MW timestamp
4287          */
4288         public function getEarliestRevTime( $flags = 0 ) {
4289                 $rev = $this->getFirstRevision( $flags );
4290                 return $rev ? $rev->getTimestamp() : null;
4291         }
4292
4293         /**
4294          * Check if this is a new page
4295          *
4296          * @return bool
4297          */
4298         public function isNewPage() {
4299                 $dbr = wfGetDB( DB_SLAVE );
4300                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4301         }
4302
4303         /**
4304          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4305          *
4306          * @return bool
4307          */
4308         public function isBigDeletion() {
4309                 global $wgDeleteRevisionsLimit;
4310
4311                 if ( !$wgDeleteRevisionsLimit ) {
4312                         return false;
4313                 }
4314
4315                 $revCount = $this->estimateRevisionCount();
4316                 return $revCount > $wgDeleteRevisionsLimit;
4317         }
4318
4319         /**
4320          * Get the  approximate revision count of this page.
4321          *
4322          * @return int
4323          */
4324         public function estimateRevisionCount() {
4325                 if ( !$this->exists() ) {
4326                         return 0;
4327                 }
4328
4329                 if ( $this->mEstimateRevisions === null ) {
4330                         $dbr = wfGetDB( DB_SLAVE );
4331                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4332                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4333                 }
4334
4335                 return $this->mEstimateRevisions;
4336         }
4337
4338         /**
4339          * Get the number of revisions between the given revision.
4340          * Used for diffs and other things that really need it.
4341          *
4342          * @param int|Revision $old Old revision or rev ID (first before range)
4343          * @param int|Revision $new New revision or rev ID (first after range)
4344          * @return Int Number of revisions between these revisions.
4345          */
4346         public function countRevisionsBetween( $old, $new ) {
4347                 if ( !( $old instanceof Revision ) ) {
4348                         $old = Revision::newFromTitle( $this, (int)$old );
4349                 }
4350                 if ( !( $new instanceof Revision ) ) {
4351                         $new = Revision::newFromTitle( $this, (int)$new );
4352                 }
4353                 if ( !$old || !$new ) {
4354                         return 0; // nothing to compare
4355                 }
4356                 $dbr = wfGetDB( DB_SLAVE );
4357                 return (int)$dbr->selectField( 'revision', 'count(*)',
4358                         array(
4359                                 'rev_page' => $this->getArticleID(),
4360                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4361                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4362                         ),
4363                         __METHOD__
4364                 );
4365         }
4366
4367         /**
4368          * Get the authors between the given revisions or revision IDs.
4369          * Used for diffs and other things that really need it.
4370          *
4371          * @since 1.23
4372          *
4373          * @param int|Revision $old Old revision or rev ID (first before range by default)
4374          * @param int|Revision $new New revision or rev ID (first after range by default)
4375          * @param int $limit Maximum number of authors
4376          * @param string|array $options (Optional): Single option, or an array of options:
4377          *     'include_old' Include $old in the range; $new is excluded.
4378          *     'include_new' Include $new in the range; $old is excluded.
4379          *     'include_both' Include both $old and $new in the range.
4380          *     Unknown option values are ignored.
4381          * @return array|null Names of revision authors in the range; null if not both revisions exist
4382          */
4383         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4384                 if ( !( $old instanceof Revision ) ) {
4385                         $old = Revision::newFromTitle( $this, (int)$old );
4386                 }
4387                 if ( !( $new instanceof Revision ) ) {
4388                         $new = Revision::newFromTitle( $this, (int)$new );
4389                 }
4390                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4391                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4392                 // in the sanity check below?
4393                 if ( !$old || !$new ) {
4394                         return null; // nothing to compare
4395                 }
4396                 $authors = array();
4397                 $old_cmp = '>';
4398                 $new_cmp = '<';
4399                 $options = (array)$options;
4400                 if ( in_array( 'include_old', $options ) ) {
4401                         $old_cmp = '>=';
4402                 }
4403                 if ( in_array( 'include_new', $options ) ) {
4404                         $new_cmp = '<=';
4405                 }
4406                 if ( in_array( 'include_both', $options ) ) {
4407                         $old_cmp = '>=';
4408                         $new_cmp = '<=';
4409                 }
4410                 // No DB query needed if $old and $new are the same or successive revisions:
4411                 if ( $old->getId() === $new->getId() ) {
4412                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? array() : array( $old->getRawUserText() );
4413                 } elseif ( $old->getId() === $new->getParentId() ) {
4414                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4415                                 $authors[] = $old->getRawUserText();
4416                                 if ( $old->getRawUserText() != $new->getRawUserText() ) {
4417                                         $authors[] = $new->getRawUserText();
4418                                 }
4419                         } elseif ( $old_cmp === '>=' ) {
4420                                 $authors[] = $old->getRawUserText();
4421                         } elseif ( $new_cmp === '<=' ) {
4422                                 $authors[] = $new->getRawUserText();
4423                         }
4424                         return $authors;
4425                 }
4426                 $dbr = wfGetDB( DB_SLAVE );
4427                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4428                         array(
4429                                 'rev_page' => $this->getArticleID(),
4430                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4431                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4432                         ), __METHOD__,
4433                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4434                 );
4435                 foreach ( $res as $row ) {
4436                         $authors[] = $row->rev_user_text;
4437                 }
4438                 return $authors;
4439         }
4440
4441         /**
4442          * Get the number of authors between the given revisions or revision IDs.
4443          * Used for diffs and other things that really need it.
4444          *
4445          * @param int|Revision $old Old revision or rev ID (first before range by default)
4446          * @param int|Revision $new New revision or rev ID (first after range by default)
4447          * @param int $limit Maximum number of authors
4448          * @param string|array $options (Optional): Single option, or an array of options:
4449          *     'include_old' Include $old in the range; $new is excluded.
4450          *     'include_new' Include $new in the range; $old is excluded.
4451          *     'include_both' Include both $old and $new in the range.
4452          *     Unknown option values are ignored.
4453          * @return int Number of revision authors in the range; zero if not both revisions exist
4454          */
4455         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4456                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4457                 return $authors ? count( $authors ) : 0;
4458         }
4459
4460         /**
4461          * Compare with another title.
4462          *
4463          * @param $title Title
4464          * @return Bool
4465          */
4466         public function equals( Title $title ) {
4467                 // Note: === is necessary for proper matching of number-like titles.
4468                 return $this->getInterwiki() === $title->getInterwiki()
4469                         && $this->getNamespace() == $title->getNamespace()
4470                         && $this->getDBkey() === $title->getDBkey();
4471         }
4472
4473         /**
4474          * Check if this title is a subpage of another title
4475          *
4476          * @param $title Title
4477          * @return Bool
4478          */
4479         public function isSubpageOf( Title $title ) {
4480                 return $this->getInterwiki() === $title->getInterwiki()
4481                         && $this->getNamespace() == $title->getNamespace()
4482                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4483         }
4484
4485         /**
4486          * Check if page exists.  For historical reasons, this function simply
4487          * checks for the existence of the title in the page table, and will
4488          * thus return false for interwiki links, special pages and the like.
4489          * If you want to know if a title can be meaningfully viewed, you should
4490          * probably call the isKnown() method instead.
4491          *
4492          * @return Bool
4493          */
4494         public function exists() {
4495                 return $this->getArticleID() != 0;
4496         }
4497
4498         /**
4499          * Should links to this title be shown as potentially viewable (i.e. as
4500          * "bluelinks"), even if there's no record by this title in the page
4501          * table?
4502          *
4503          * This function is semi-deprecated for public use, as well as somewhat
4504          * misleadingly named.  You probably just want to call isKnown(), which
4505          * calls this function internally.
4506          *
4507          * (ISSUE: Most of these checks are cheap, but the file existence check
4508          * can potentially be quite expensive.  Including it here fixes a lot of
4509          * existing code, but we might want to add an optional parameter to skip
4510          * it and any other expensive checks.)
4511          *
4512          * @return Bool
4513          */
4514         public function isAlwaysKnown() {
4515                 $isKnown = null;
4516
4517                 /**
4518                  * Allows overriding default behavior for determining if a page exists.
4519                  * If $isKnown is kept as null, regular checks happen. If it's
4520                  * a boolean, this value is returned by the isKnown method.
4521                  *
4522                  * @since 1.20
4523                  *
4524                  * @param Title $title
4525                  * @param boolean|null $isKnown
4526                  */
4527                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4528
4529                 if ( !is_null( $isKnown ) ) {
4530                         return $isKnown;
4531                 }
4532
4533                 if ( $this->isExternal() ) {
4534                         return true;  // any interwiki link might be viewable, for all we know
4535                 }
4536
4537                 switch ( $this->mNamespace ) {
4538                         case NS_MEDIA:
4539                         case NS_FILE:
4540                                 // file exists, possibly in a foreign repo
4541                                 return (bool)wfFindFile( $this );
4542                         case NS_SPECIAL:
4543                                 // valid special page
4544                                 return SpecialPageFactory::exists( $this->getDBkey() );
4545                         case NS_MAIN:
4546                                 // selflink, possibly with fragment
4547                                 return $this->mDbkeyform == '';
4548                         case NS_MEDIAWIKI:
4549                                 // known system message
4550                                 return $this->hasSourceText() !== false;
4551                         default:
4552                                 return false;
4553                 }
4554         }
4555
4556         /**
4557          * Does this title refer to a page that can (or might) be meaningfully
4558          * viewed?  In particular, this function may be used to determine if
4559          * links to the title should be rendered as "bluelinks" (as opposed to
4560          * "redlinks" to non-existent pages).
4561          * Adding something else to this function will cause inconsistency
4562          * since LinkHolderArray calls isAlwaysKnown() and does its own
4563          * page existence check.
4564          *
4565          * @return Bool
4566          */
4567         public function isKnown() {
4568                 return $this->isAlwaysKnown() || $this->exists();
4569         }
4570
4571         /**
4572          * Does this page have source text?
4573          *
4574          * @return Boolean
4575          */
4576         public function hasSourceText() {
4577                 if ( $this->exists() ) {
4578                         return true;
4579                 }
4580
4581                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4582                         // If the page doesn't exist but is a known system message, default
4583                         // message content will be displayed, same for language subpages-
4584                         // Use always content language to avoid loading hundreds of languages
4585                         // to get the link color.
4586                         global $wgContLang;
4587                         list( $name, ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4588                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4589                         return $message->exists();
4590                 }
4591
4592                 return false;
4593         }
4594
4595         /**
4596          * Get the default message text or false if the message doesn't exist
4597          *
4598          * @return String or false
4599          */
4600         public function getDefaultMessageText() {
4601                 global $wgContLang;
4602
4603                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4604                         return false;
4605                 }
4606
4607                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4608                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4609
4610                 if ( $message->exists() ) {
4611                         return $message->plain();
4612                 } else {
4613                         return false;
4614                 }
4615         }
4616
4617         /**
4618          * Updates page_touched for this page; called from LinksUpdate.php
4619          *
4620          * @return Bool true if the update succeeded
4621          */
4622         public function invalidateCache() {
4623                 if ( wfReadOnly() ) {
4624                         return false;
4625                 }
4626
4627                 $method = __METHOD__;
4628                 $dbw = wfGetDB( DB_MASTER );
4629                 $conds = $this->pageCond();
4630                 $dbw->onTransactionIdle( function() use ( $dbw, $conds, $method ) {
4631                         $dbw->update(
4632                                 'page',
4633                                 array( 'page_touched' => $dbw->timestamp() ),
4634                                 $conds,
4635                                 $method
4636                         );
4637                 } );
4638
4639                 return true;
4640         }
4641
4642         /**
4643          * Update page_touched timestamps and send squid purge messages for
4644          * pages linking to this title. May be sent to the job queue depending
4645          * on the number of links. Typically called on create and delete.
4646          */
4647         public function touchLinks() {
4648                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4649                 $u->doUpdate();
4650
4651                 if ( $this->getNamespace() == NS_CATEGORY ) {
4652                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4653                         $u->doUpdate();
4654                 }
4655         }
4656
4657         /**
4658          * Get the last touched timestamp
4659          *
4660          * @param $db DatabaseBase: optional db
4661          * @return String last-touched timestamp
4662          */
4663         public function getTouched( $db = null ) {
4664                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4665                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4666                 return $touched;
4667         }
4668
4669         /**
4670          * Get the timestamp when this page was updated since the user last saw it.
4671          *
4672          * @param $user User
4673          * @return String|Null
4674          */
4675         public function getNotificationTimestamp( $user = null ) {
4676                 global $wgUser, $wgShowUpdatedMarker;
4677                 // Assume current user if none given
4678                 if ( !$user ) {
4679                         $user = $wgUser;
4680                 }
4681                 // Check cache first
4682                 $uid = $user->getId();
4683                 // avoid isset here, as it'll return false for null entries
4684                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4685                         return $this->mNotificationTimestamp[$uid];
4686                 }
4687                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4688                         $this->mNotificationTimestamp[$uid] = false;
4689                         return $this->mNotificationTimestamp[$uid];
4690                 }
4691                 // Don't cache too much!
4692                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4693                         $this->mNotificationTimestamp = array();
4694                 }
4695                 $dbr = wfGetDB( DB_SLAVE );
4696                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4697                         'wl_notificationtimestamp',
4698                         array(
4699                                 'wl_user' => $user->getId(),
4700                                 'wl_namespace' => $this->getNamespace(),
4701                                 'wl_title' => $this->getDBkey(),
4702                         ),
4703                         __METHOD__
4704                 );
4705                 return $this->mNotificationTimestamp[$uid];
4706         }
4707
4708         /**
4709          * Generate strings used for xml 'id' names in monobook tabs
4710          *
4711          * @param string $prepend defaults to 'nstab-'
4712          * @return String XML 'id' name
4713          */
4714         public function getNamespaceKey( $prepend = 'nstab-' ) {
4715                 global $wgContLang;
4716                 // Gets the subject namespace if this title
4717                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4718                 // Checks if canonical namespace name exists for namespace
4719                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4720                         // Uses canonical namespace name
4721                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4722                 } else {
4723                         // Uses text of namespace
4724                         $namespaceKey = $this->getSubjectNsText();
4725                 }
4726                 // Makes namespace key lowercase
4727                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4728                 // Uses main
4729                 if ( $namespaceKey == '' ) {
4730                         $namespaceKey = 'main';
4731                 }
4732                 // Changes file to image for backwards compatibility
4733                 if ( $namespaceKey == 'file' ) {
4734                         $namespaceKey = 'image';
4735                 }
4736                 return $prepend . $namespaceKey;
4737         }
4738
4739         /**
4740          * Get all extant redirects to this Title
4741          *
4742          * @param int|Null $ns Single namespace to consider; NULL to consider all namespaces
4743          * @return Title[] Array of Title redirects to this title
4744          */
4745         public function getRedirectsHere( $ns = null ) {
4746                 $redirs = array();
4747
4748                 $dbr = wfGetDB( DB_SLAVE );
4749                 $where = array(
4750                         'rd_namespace' => $this->getNamespace(),
4751                         'rd_title' => $this->getDBkey(),
4752                         'rd_from = page_id'
4753                 );
4754                 if ( $this->isExternal() ) {
4755                         $where['rd_interwiki'] = $this->getInterwiki();
4756                 } else {
4757                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4758                 }
4759                 if ( !is_null( $ns ) ) {
4760                         $where['page_namespace'] = $ns;
4761                 }
4762
4763                 $res = $dbr->select(
4764                         array( 'redirect', 'page' ),
4765                         array( 'page_namespace', 'page_title' ),
4766                         $where,
4767                         __METHOD__
4768                 );
4769
4770                 foreach ( $res as $row ) {
4771                         $redirs[] = self::newFromRow( $row );
4772                 }
4773                 return $redirs;
4774         }
4775
4776         /**
4777          * Check if this Title is a valid redirect target
4778          *
4779          * @return Bool
4780          */
4781         public function isValidRedirectTarget() {
4782                 global $wgInvalidRedirectTargets;
4783
4784                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4785                 if ( $this->isSpecial( 'Userlogout' ) ) {
4786                         return false;
4787                 }
4788
4789                 foreach ( $wgInvalidRedirectTargets as $target ) {
4790                         if ( $this->isSpecial( $target ) ) {
4791                                 return false;
4792                         }
4793                 }
4794
4795                 return true;
4796         }
4797
4798         /**
4799          * Get a backlink cache object
4800          *
4801          * @return BacklinkCache
4802          */
4803         public function getBacklinkCache() {
4804                 return BacklinkCache::get( $this );
4805         }
4806
4807         /**
4808          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4809          *
4810          * @return Boolean
4811          */
4812         public function canUseNoindex() {
4813                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4814
4815                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4816                         ? $wgContentNamespaces
4817                         : $wgExemptFromUserRobotsControl;
4818
4819                 return !in_array( $this->mNamespace, $bannedNamespaces );
4820
4821         }
4822
4823         /**
4824          * Returns the raw sort key to be used for categories, with the specified
4825          * prefix.  This will be fed to Collation::getSortKey() to get a
4826          * binary sortkey that can be used for actual sorting.
4827          *
4828          * @param string $prefix The prefix to be used, specified using
4829          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4830          *   prefix.
4831          * @return string
4832          */
4833         public function getCategorySortkey( $prefix = '' ) {
4834                 $unprefixed = $this->getText();
4835
4836                 // Anything that uses this hook should only depend
4837                 // on the Title object passed in, and should probably
4838                 // tell the users to run updateCollations.php --force
4839                 // in order to re-sort existing category relations.
4840                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4841                 if ( $prefix !== '' ) {
4842                         # Separate with a line feed, so the unprefixed part is only used as
4843                         # a tiebreaker when two pages have the exact same prefix.
4844                         # In UCA, tab is the only character that can sort above LF
4845                         # so we strip both of them from the original prefix.
4846                         $prefix = strtr( $prefix, "\n\t", '  ' );
4847                         return "$prefix\n$unprefixed";
4848                 }
4849                 return $unprefixed;
4850         }
4851
4852         /**
4853          * Get the language in which the content of this page is written in
4854          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4855          * e.g. $wgLang (such as special pages, which are in the user language).
4856          *
4857          * @since 1.18
4858          * @return Language
4859          */
4860         public function getPageLanguage() {
4861                 global $wgLang, $wgLanguageCode;
4862                 wfProfileIn( __METHOD__ );
4863                 if ( $this->isSpecialPage() ) {
4864                         // special pages are in the user language
4865                         wfProfileOut( __METHOD__ );
4866                         return $wgLang;
4867                 }
4868
4869                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4870                         // Note that this may depend on user settings, so the cache should be only per-request.
4871                         // NOTE: ContentHandler::getPageLanguage() may need to load the content to determine the page language!
4872                         // Checking $wgLanguageCode hasn't changed for the benefit of unit tests.
4873                         $contentHandler = ContentHandler::getForTitle( $this );
4874                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4875                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4876                 } else {
4877                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4878                 }
4879                 wfProfileOut( __METHOD__ );
4880                 return $langObj;
4881         }
4882
4883         /**
4884          * Get the language in which the content of this page is written when
4885          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4886          * e.g. $wgLang (such as special pages, which are in the user language).
4887          *
4888          * @since 1.20
4889          * @return Language
4890          */
4891         public function getPageViewLanguage() {
4892                 global $wgLang;
4893
4894                 if ( $this->isSpecialPage() ) {
4895                         // If the user chooses a variant, the content is actually
4896                         // in a language whose code is the variant code.
4897                         $variant = $wgLang->getPreferredVariant();
4898                         if ( $wgLang->getCode() !== $variant ) {
4899                                 return Language::factory( $variant );
4900                         }
4901
4902                         return $wgLang;
4903                 }
4904
4905                 //NOTE: can't be cached persistently, depends on user settings
4906                 //NOTE: ContentHandler::getPageViewLanguage() may need to load the content to determine the page language!
4907                 $contentHandler = ContentHandler::getForTitle( $this );
4908                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4909                 return $pageLang;
4910         }
4911
4912         /**
4913          * Get a list of rendered edit notices for this page.
4914          *
4915          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4916          * they will already be wrapped in paragraphs.
4917          *
4918          * @since 1.21
4919          * @param int oldid Revision ID that's being edited
4920          * @return Array
4921          */
4922         public function getEditNotices( $oldid = 0 ) {
4923                 $notices = array();
4924
4925                 # Optional notices on a per-namespace and per-page basis
4926                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4927                 $editnotice_ns_message = wfMessage( $editnotice_ns );
4928                 if ( $editnotice_ns_message->exists() ) {
4929                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
4930                 }
4931                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4932                         $parts = explode( '/', $this->getDBkey() );
4933                         $editnotice_base = $editnotice_ns;
4934                         while ( count( $parts ) > 0 ) {
4935                                 $editnotice_base .= '-' . array_shift( $parts );
4936                                 $editnotice_base_msg = wfMessage( $editnotice_base );
4937                                 if ( $editnotice_base_msg->exists() ) {
4938                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
4939                                 }
4940                         }
4941                 } else {
4942                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
4943                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4944                         $editnoticeMsg = wfMessage( $editnoticeText );
4945                         if ( $editnoticeMsg->exists() ) {
4946                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
4947                         }
4948                 }
4949
4950                 wfRunHooks( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
4951                 return $notices;
4952         }
4953 }