includes/Title.php

   1 <?php
   2 /**
   3  * Representation of a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  31  *       and does not rely on global state or the database.
  32  *
  33  * @internal documentation reviewed 15 Mar 2010
  34  */
  35 class Title {
  36         /** @var MapCacheLRU */
  37         static private $titleCache = null;
  38
  39         /**
  40          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  41          * commonly used titles. On a batch operation this can become a memory leak
  42          * if not bounded. After hitting this many titles reset the cache.
  43          */
  44         const CACHE_MAX = 1000;
  45
  46         /**
  47          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  48          * to use the master DB
  49          */
  50         const GAID_FOR_UPDATE = 1;
  51
  52         /**
  53          * @name Private member variables
  54          * Please use the accessor functions instead.
  55          * @private
  56          */
  57         // @{
  58
  59         /** @var string Text form (spaces not underscores) of the main part */
  60         public $mTextform = '';
  61
  62         /** @var string URL-encoded form of the main part */
  63         public $mUrlform = '';
  64
  65         /** @var string Main part with underscores */
  66         public $mDbkeyform = '';
  67
  68         /** @var string Database key with the initial letter in the case specified by the user */
  69         protected $mUserCaseDBKey;
  70
  71         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  72         public $mNamespace = NS_MAIN;
  73
  74         /** @var string Interwiki prefix */
  75         public $mInterwiki = '';
  76
  77         /** @var bool Was this Title created from a string with a local interwiki prefix? */
  78         private $mLocalInterwiki = false;
  79
  80         /** @var string Title fragment (i.e. the bit after the #) */
  81         public $mFragment = '';
  82
  83         /** @var int Article ID, fetched from the link cache on demand */
  84         public $mArticleID = -1;
  85
  86         /** @var bool|int ID of most recent revision */
  87         protected $mLatestID = false;
  88
  89         /**
  90          * @var bool|string ID of the page's content model, i.e. one of the
  91          *   CONTENT_MODEL_XXX constants
  92          */
  93         public $mContentModel = false;
  94
  95         /** @var int Estimated number of revisions; null of not loaded */
  96         private $mEstimateRevisions;
  97
  98         /** @var array Array of groups allowed to edit this article */
  99         public $mRestrictions = array();
 100
 101         /** @var bool */
 102         protected $mOldRestrictions = false;
 103
 104         /** @var bool Cascade restrictions on this page to included templates and images? */
 105         public $mCascadeRestriction;
 106
 107         /** Caching the results of getCascadeProtectionSources */
 108         public $mCascadingRestrictions;
 109
 110         /** @var array When do the restrictions on this page expire? */
 111         protected $mRestrictionsExpiry = array();
 112
 113         /** @var bool Are cascading restrictions in effect on this page? */
 114         protected $mHasCascadingRestrictions;
 115
 116         /** @var array Where are the cascading restrictions coming from on this page? */
 117         public $mCascadeSources;
 118
 119         /** @var bool Boolean for initialisation on demand */
 120         public $mRestrictionsLoaded = false;
 121
 122         /** @var string Text form including namespace/interwiki, initialised on demand */
 123         protected $mPrefixedText = null;
 124
 125         /** @var mixed Cached value for getTitleProtection (create protection) */
 126         public $mTitleProtection;
 127
 128         /**
 129          * @var int Namespace index when there is no namespace. Don't change the
 130          *   following default, NS_MAIN is hardcoded in several places. See bug 696.
 131          *   Zero except in {{transclusion}} tags.
 132          */
 133         public $mDefaultNamespace = NS_MAIN;
 134
 135         /**
 136          * @var bool Is $wgUser watching this page? null if unfilled, accessed
 137          * through userIsWatching()
 138          */
 139         protected $mWatched = null;
 140
 141         /** @var int The page length, 0 for special pages */
 142         protected $mLength = -1;
 143
 144         /** @var null Is the article at this title a redirect? */
 145         public $mRedirect = null;
 146
 147         /** @var array Associative array of user ID -> timestamp/false */
 148         private $mNotificationTimestamp = array();
 149
 150         /** @var bool Whether a page has any subpages */
 151         private $mHasSubpages;
 152
 153         /** @var bool The (string) language code of the page's language and content code. */
 154         private $mPageLanguage = false;
 155
 156         /** @var string The page language code from the database */
 157         private $mDbPageLanguage = null;
 158
 159         /** @var TitleValue A corresponding TitleValue object */
 160         private $mTitleValue = null;
 161
 162         /** @var bool Would deleting this page be a big deletion? */
 163         private $mIsBigDeletion = null;
 164         // @}
 165
 166         /**
 167          * B/C kludge: provide a TitleParser for use by Title.
 168          * Ideally, Title would have no methods that need this.
 169          * Avoid usage of this singleton by using TitleValue
 170          * and the associated services when possible.
 171          *
 172          * @return TitleParser
 173          */
 174         private static function getTitleParser() {
 175                 global $wgContLang, $wgLocalInterwikis;
 176
 177                 static $titleCodec = null;
 178                 static $titleCodecFingerprint = null;
 179
 180                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 181                 // make sure we are using the right one. To detect changes over the course
 182                 // of a request, we remember a fingerprint of the config used to create the
 183                 // codec singleton, and re-create it if the fingerprint doesn't match.
 184                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . join( '+', $wgLocalInterwikis );
 185
 186                 if ( $fingerprint !== $titleCodecFingerprint ) {
 187                         $titleCodec = null;
 188                 }
 189
 190                 if ( !$titleCodec ) {
 191                         $titleCodec = new MediaWikiTitleCodec(
 192                                 $wgContLang,
 193                                 GenderCache::singleton(),
 194                                 $wgLocalInterwikis
 195                         );
 196                         $titleCodecFingerprint = $fingerprint;
 197                 }
 198
 199                 return $titleCodec;
 200         }
 201
 202         /**
 203          * B/C kludge: provide a TitleParser for use by Title.
 204          * Ideally, Title would have no methods that need this.
 205          * Avoid usage of this singleton by using TitleValue
 206          * and the associated services when possible.
 207          *
 208          * @return TitleFormatter
 209          */
 210         private static function getTitleFormatter() {
 211                 //NOTE: we know that getTitleParser() returns a MediaWikiTitleCodec,
 212                 //      which implements TitleFormatter.
 213                 return self::getTitleParser();
 214         }
 215
 216         function __construct() {
 217         }
 218
 219         /**
 220          * Create a new Title from a prefixed DB key
 221          *
 222          * @param string $key The database key, which has underscores
 223          *      instead of spaces, possibly including namespace and
 224          *      interwiki prefixes
 225          * @return Title|null Title, or null on an error
 226          */
 227         public static function newFromDBkey( $key ) {
 228                 $t = new Title();
 229                 $t->mDbkeyform = $key;
 230                 if ( $t->secureAndSplit() ) {
 231                         return $t;
 232                 } else {
 233                         return null;
 234                 }
 235         }
 236
 237         /**
 238          * Create a new Title from a TitleValue
 239          *
 240          * @param TitleValue $titleValue Assumed to be safe.
 241          *
 242          * @return Title
 243          */
 244         public static function newFromTitleValue( TitleValue $titleValue ) {
 245                 return self::makeTitle(
 246                         $titleValue->getNamespace(),
 247                         $titleValue->getText(),
 248                         $titleValue->getFragment() );
 249         }
 250
 251         /**
 252          * Create a new Title from text, such as what one would find in a link. De-
 253          * codes any HTML entities in the text.
 254          *
 255          * @param string $text The link text; spaces, prefixes, and an
 256          *   initial ':' indicating the main namespace are accepted.
 257          * @param int $defaultNamespace The namespace to use if none is specified
 258          *   by a prefix.  If you want to force a specific namespace even if
 259          *   $text might begin with a namespace prefix, use makeTitle() or
 260          *   makeTitleSafe().
 261          * @throws MWException
 262          * @return Title|null Title or null on an error.
 263          */
 264         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 265                 if ( is_object( $text ) ) {
 266                         throw new MWException( 'Title::newFromText given an object' );
 267                 }
 268
 269                 $cache = self::getTitleCache();
 270
 271                 /**
 272                  * Wiki pages often contain multiple links to the same page.
 273                  * Title normalization and parsing can become expensive on
 274                  * pages with many links, so we can save a little time by
 275                  * caching them.
 276                  *
 277                  * In theory these are value objects and won't get changed...
 278                  */
 279                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 280                         return $cache->get( $text );
 281                 }
 282
 283                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 284                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 285
 286                 $t = new Title();
 287                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 288                 $t->mDefaultNamespace = intval( $defaultNamespace );
 289
 290                 if ( $t->secureAndSplit() ) {
 291                         if ( $defaultNamespace == NS_MAIN ) {
 292                                 $cache->set( $text, $t );
 293                         }
 294                         return $t;
 295                 } else {
 296                         return null;
 297                 }
 298         }
 299
 300         /**
 301          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 302          *
 303          * Example of wrong and broken code:
 304          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 305          *
 306          * Example of right code:
 307          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 308          *
 309          * Create a new Title from URL-encoded text. Ensures that
 310          * the given title's length does not exceed the maximum.
 311          *
 312          * @param string $url The title, as might be taken from a URL
 313          * @return Title|null The new object, or null on an error
 314          */
 315         public static function newFromURL( $url ) {
 316                 $t = new Title();
 317
 318                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 319                 # but some URLs used it as a space replacement and they still come
 320                 # from some external search tools.
 321                 if ( strpos( self::legalChars(), '+' ) === false ) {
 322                         $url = str_replace( '+', ' ', $url );
 323                 }
 324
 325                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 326                 if ( $t->secureAndSplit() ) {
 327                         return $t;
 328                 } else {
 329                         return null;
 330                 }
 331         }
 332
 333         /**
 334          * @return MapCacheLRU
 335          */
 336         private static function getTitleCache() {
 337                 if ( self::$titleCache == null ) {
 338                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 339                 }
 340                 return self::$titleCache;
 341         }
 342
 343         /**
 344          * Returns a list of fields that are to be selected for initializing Title
 345          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 346          * whether to include page_content_model.
 347          *
 348          * @return array
 349          */
 350         protected static function getSelectFields() {
 351                 global $wgContentHandlerUseDB;
 352
 353                 $fields = array(
 354                         'page_namespace', 'page_title', 'page_id',
 355                         'page_len', 'page_is_redirect', 'page_latest',
 356                 );
 357
 358                 if ( $wgContentHandlerUseDB ) {
 359                         $fields[] = 'page_content_model';
 360                 }
 361
 362                 return $fields;
 363         }
 364
 365         /**
 366          * Create a new Title from an article ID
 367          *
 368          * @param int $id The page_id corresponding to the Title to create
 369          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 370          * @return Title|null The new object, or null on an error
 371          */
 372         public static function newFromID( $id, $flags = 0 ) {
 373                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 374                 $row = $db->selectRow(
 375                         'page',
 376                         self::getSelectFields(),
 377                         array( 'page_id' => $id ),
 378                         __METHOD__
 379                 );
 380                 if ( $row !== false ) {
 381                         $title = Title::newFromRow( $row );
 382                 } else {
 383                         $title = null;
 384                 }
 385                 return $title;
 386         }
 387
 388         /**
 389          * Make an array of titles from an array of IDs
 390          *
 391          * @param int[] $ids Array of IDs
 392          * @return Title[] Array of Titles
 393          */
 394         public static function newFromIDs( $ids ) {
 395                 if ( !count( $ids ) ) {
 396                         return array();
 397                 }
 398                 $dbr = wfGetDB( DB_SLAVE );
 399
 400                 $res = $dbr->select(
 401                         'page',
 402                         self::getSelectFields(),
 403                         array( 'page_id' => $ids ),
 404                         __METHOD__
 405                 );
 406
 407                 $titles = array();
 408                 foreach ( $res as $row ) {
 409                         $titles[] = Title::newFromRow( $row );
 410                 }
 411                 return $titles;
 412         }
 413
 414         /**
 415          * Make a Title object from a DB row
 416          *
 417          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 418          * @return Title Corresponding Title
 419          */
 420         public static function newFromRow( $row ) {
 421                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 422                 $t->loadFromRow( $row );
 423                 return $t;
 424         }
 425
 426         /**
 427          * Load Title object fields from a DB row.
 428          * If false is given, the title will be treated as non-existing.
 429          *
 430          * @param stdClass|bool $row Database row
 431          */
 432         public function loadFromRow( $row ) {
 433                 if ( $row ) { // page found
 434                         if ( isset( $row->page_id ) ) {
 435                                 $this->mArticleID = (int)$row->page_id;
 436                         }
 437                         if ( isset( $row->page_len ) ) {
 438                                 $this->mLength = (int)$row->page_len;
 439                         }
 440                         if ( isset( $row->page_is_redirect ) ) {
 441                                 $this->mRedirect = (bool)$row->page_is_redirect;
 442                         }
 443                         if ( isset( $row->page_latest ) ) {
 444                                 $this->mLatestID = (int)$row->page_latest;
 445                         }
 446                         if ( isset( $row->page_content_model ) ) {
 447                                 $this->mContentModel = strval( $row->page_content_model );
 448                         } else {
 449                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 450                         }
 451                         if ( isset( $row->page_lang ) ) {
 452                                 $this->mDbPageLanguage = (string)$row->page_lang;
 453                         }
 454                 } else { // page not found
 455                         $this->mArticleID = 0;
 456                         $this->mLength = 0;
 457                         $this->mRedirect = false;
 458                         $this->mLatestID = 0;
 459                         $this->mContentModel = false; # initialized lazily in getContentModel()
 460                 }
 461         }
 462
 463         /**
 464          * Create a new Title from a namespace index and a DB key.
 465          * It's assumed that $ns and $title are *valid*, for instance when
 466          * they came directly from the database or a special page name.
 467          * For convenience, spaces are converted to underscores so that
 468          * eg user_text fields can be used directly.
 469          *
 470          * @param int $ns The namespace of the article
 471          * @param string $title The unprefixed database key form
 472          * @param string $fragment The link fragment (after the "#")
 473          * @param string $interwiki The interwiki prefix
 474          * @return Title The new object
 475          */
 476         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 477                 $t = new Title();
 478                 $t->mInterwiki = $interwiki;
 479                 $t->mFragment = $fragment;
 480                 $t->mNamespace = $ns = intval( $ns );
 481                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 482                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 483                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 484                 $t->mTextform = str_replace( '_', ' ', $title );
 485                 $t->mContentModel = false; # initialized lazily in getContentModel()
 486                 return $t;
 487         }
 488
 489         /**
 490          * Create a new Title from a namespace index and a DB key.
 491          * The parameters will be checked for validity, which is a bit slower
 492          * than makeTitle() but safer for user-provided data.
 493          *
 494          * @param int $ns The namespace of the article
 495          * @param string $title Database key form
 496          * @param string $fragment The link fragment (after the "#")
 497          * @param string $interwiki Interwiki prefix
 498          * @return Title The new object, or null on an error
 499          */
 500         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 501                 if ( !MWNamespace::exists( $ns ) ) {
 502                         return null;
 503                 }
 504
 505                 $t = new Title();
 506                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 507                 if ( $t->secureAndSplit() ) {
 508                         return $t;
 509                 } else {
 510                         return null;
 511                 }
 512         }
 513
 514         /**
 515          * Create a new Title for the Main Page
 516          *
 517          * @return Title The new object
 518          */
 519         public static function newMainPage() {
 520                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 521                 // Don't give fatal errors if the message is broken
 522                 if ( !$title ) {
 523                         $title = Title::newFromText( 'Main Page' );
 524                 }
 525                 return $title;
 526         }
 527
 528         /**
 529          * Extract a redirect destination from a string and return the
 530          * Title, or null if the text doesn't contain a valid redirect
 531          * This will only return the very next target, useful for
 532          * the redirect table and other checks that don't need full recursion
 533          *
 534          * @param string $text Text with possible redirect
 535          * @return Title The corresponding Title
 536          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 537          */
 538         public static function newFromRedirect( $text ) {
 539                 ContentHandler::deprecated( __METHOD__, '1.21' );
 540
 541                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 542                 return $content->getRedirectTarget();
 543         }
 544
 545         /**
 546          * Extract a redirect destination from a string and return the
 547          * Title, or null if the text doesn't contain a valid redirect
 548          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 549          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 550          *
 551          * @param string $text Text with possible redirect
 552          * @return Title
 553          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 554          */
 555         public static function newFromRedirectRecurse( $text ) {
 556                 ContentHandler::deprecated( __METHOD__, '1.21' );
 557
 558                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 559                 return $content->getUltimateRedirectTarget();
 560         }
 561
 562         /**
 563          * Extract a redirect destination from a string and return an
 564          * array of Titles, or null if the text doesn't contain a valid redirect
 565          * The last element in the array is the final destination after all redirects
 566          * have been resolved (up to $wgMaxRedirects times)
 567          *
 568          * @param string $text Text with possible redirect
 569          * @return Title[] Array of Titles, with the destination last
 570          * @deprecated since 1.21, use Content::getRedirectChain instead.
 571          */
 572         public static function newFromRedirectArray( $text ) {
 573                 ContentHandler::deprecated( __METHOD__, '1.21' );
 574
 575                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 576                 return $content->getRedirectChain();
 577         }
 578
 579         /**
 580          * Get the prefixed DB key associated with an ID
 581          *
 582          * @param int $id The page_id of the article
 583          * @return Title|null An object representing the article, or null if no such article was found
 584          */
 585         public static function nameOf( $id ) {
 586                 $dbr = wfGetDB( DB_SLAVE );
 587
 588                 $s = $dbr->selectRow(
 589                         'page',
 590                         array( 'page_namespace', 'page_title' ),
 591                         array( 'page_id' => $id ),
 592                         __METHOD__
 593                 );
 594                 if ( $s === false ) {
 595                         return null;
 596                 }
 597
 598                 $n = self::makeName( $s->page_namespace, $s->page_title );
 599                 return $n;
 600         }
 601
 602         /**
 603          * Get a regex character class describing the legal characters in a link
 604          *
 605          * @return string The list of characters, not delimited
 606          */
 607         public static function legalChars() {
 608                 global $wgLegalTitleChars;
 609                 return $wgLegalTitleChars;
 610         }
 611
 612         /**
 613          * Returns a simple regex that will match on characters and sequences invalid in titles.
 614          * Note that this doesn't pick up many things that could be wrong with titles, but that
 615          * replacing this regex with something valid will make many titles valid.
 616          *
 617          * @todo move this into MediaWikiTitleCodec
 618          *
 619          * @return string Regex string
 620          */
 621         static function getTitleInvalidRegex() {
 622                 static $rxTc = false;
 623                 if ( !$rxTc ) {
 624                         # Matching titles will be held as illegal.
 625                         $rxTc = '/' .
 626                                 # Any character not allowed is forbidden...
 627                                 '[^' . self::legalChars() . ']' .
 628                                 # URL percent encoding sequences interfere with the ability
 629                                 # to round-trip titles -- you can't link to them consistently.
 630                                 '|%[0-9A-Fa-f]{2}' .
 631                                 # XML/HTML character references produce similar issues.
 632                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 633                                 '|&#[0-9]+;' .
 634                                 '|&#x[0-9A-Fa-f]+;' .
 635                                 '/S';
 636                 }
 637
 638                 return $rxTc;
 639         }
 640
 641         /**
 642          * Utility method for converting a character sequence from bytes to Unicode.
 643          *
 644          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 645          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 646          *
 647          * @param string $byteClass
 648          * @return string
 649          */
 650         public static function convertByteClassToUnicodeClass( $byteClass ) {
 651                 $length = strlen( $byteClass );
 652                 // Input token queue
 653                 $x0 = $x1 = $x2 = '';
 654                 // Decoded queue
 655                 $d0 = $d1 = $d2 = '';
 656                 // Decoded integer codepoints
 657                 $ord0 = $ord1 = $ord2 = 0;
 658                 // Re-encoded queue
 659                 $r0 = $r1 = $r2 = '';
 660                 // Output
 661                 $out = '';
 662                 // Flags
 663                 $allowUnicode = false;
 664                 for ( $pos = 0; $pos < $length; $pos++ ) {
 665                         // Shift the queues down
 666                         $x2 = $x1;
 667                         $x1 = $x0;
 668                         $d2 = $d1;
 669                         $d1 = $d0;
 670                         $ord2 = $ord1;
 671                         $ord1 = $ord0;
 672                         $r2 = $r1;
 673                         $r1 = $r0;
 674                         // Load the current input token and decoded values
 675                         $inChar = $byteClass[$pos];
 676                         if ( $inChar == '\\' ) {
 677                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 678                                         $x0 = $inChar . $m[0];
 679                                         $d0 = chr( hexdec( $m[1] ) );
 680                                         $pos += strlen( $m[0] );
 681                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 682                                         $x0 = $inChar . $m[0];
 683                                         $d0 = chr( octdec( $m[0] ) );
 684                                         $pos += strlen( $m[0] );
 685                                 } elseif ( $pos + 1 >= $length ) {
 686                                         $x0 = $d0 = '\\';
 687                                 } else {
 688                                         $d0 = $byteClass[$pos + 1];
 689                                         $x0 = $inChar . $d0;
 690                                         $pos += 1;
 691                                 }
 692                         } else {
 693                                 $x0 = $d0 = $inChar;
 694                         }
 695                         $ord0 = ord( $d0 );
 696                         // Load the current re-encoded value
 697                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 698                                 $r0 = sprintf( '\x%02x', $ord0 );
 699                         } elseif ( $ord0 >= 0x80 ) {
 700                                 // Allow unicode if a single high-bit character appears
 701                                 $r0 = sprintf( '\x%02x', $ord0 );
 702                                 $allowUnicode = true;
 703                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 704                                 $r0 = '\\' . $d0;
 705                         } else {
 706                                 $r0 = $d0;
 707                         }
 708                         // Do the output
 709                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 710                                 // Range
 711                                 if ( $ord2 > $ord0 ) {
 712                                         // Empty range
 713                                 } elseif ( $ord0 >= 0x80 ) {
 714                                         // Unicode range
 715                                         $allowUnicode = true;
 716                                         if ( $ord2 < 0x80 ) {
 717                                                 // Keep the non-unicode section of the range
 718                                                 $out .= "$r2-\\x7F";
 719                                         }
 720                                 } else {
 721                                         // Normal range
 722                                         $out .= "$r2-$r0";
 723                                 }
 724                                 // Reset state to the initial value
 725                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 726                         } elseif ( $ord2 < 0x80 ) {
 727                                 // ASCII character
 728                                 $out .= $r2;
 729                         }
 730                 }
 731                 if ( $ord1 < 0x80 ) {
 732                         $out .= $r1;
 733                 }
 734                 if ( $ord0 < 0x80 ) {
 735                         $out .= $r0;
 736                 }
 737                 if ( $allowUnicode ) {
 738                         $out .= '\u0080-\uFFFF';
 739                 }
 740                 return $out;
 741         }
 742
 743         /**
 744          * Make a prefixed DB key from a DB key and a namespace index
 745          *
 746          * @param int $ns Numerical representation of the namespace
 747          * @param string $title The DB key form the title
 748          * @param string $fragment The link fragment (after the "#")
 749          * @param string $interwiki The interwiki prefix
 750          * @return string The prefixed form of the title
 751          */
 752         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 753                 global $wgContLang;
 754
 755                 $namespace = $wgContLang->getNsText( $ns );
 756                 $name = $namespace == '' ? $title : "$namespace:$title";
 757                 if ( strval( $interwiki ) != '' ) {
 758                         $name = "$interwiki:$name";
 759                 }
 760                 if ( strval( $fragment ) != '' ) {
 761                         $name .= '#' . $fragment;
 762                 }
 763                 return $name;
 764         }
 765
 766         /**
 767          * Escape a text fragment, say from a link, for a URL
 768          *
 769          * @param string $fragment Containing a URL or link fragment (after the "#")
 770          * @return string Escaped string
 771          */
 772         static function escapeFragmentForURL( $fragment ) {
 773                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 774                 # fragments appear not to work in IE (at least up to 7) or in at least
 775                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 776                 # to care if they aren't encoded.
 777                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 778         }
 779
 780         /**
 781          * Callback for usort() to do title sorts by (namespace, title)
 782          *
 783          * @param Title $a
 784          * @param Title $b
 785          *
 786          * @return int Result of string comparison, or namespace comparison
 787          */
 788         public static function compare( $a, $b ) {
 789                 if ( $a->getNamespace() == $b->getNamespace() ) {
 790                         return strcmp( $a->getText(), $b->getText() );
 791                 } else {
 792                         return $a->getNamespace() - $b->getNamespace();
 793                 }
 794         }
 795
 796         /**
 797          * Determine whether the object refers to a page within
 798          * this project.
 799          *
 800          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 801          */
 802         public function isLocal() {
 803                 if ( $this->isExternal() ) {
 804                         $iw = Interwiki::fetch( $this->mInterwiki );
 805                         if ( $iw ) {
 806                                 return $iw->isLocal();
 807                         }
 808                 }
 809                 return true;
 810         }
 811
 812         /**
 813          * Is this Title interwiki?
 814          *
 815          * @return bool
 816          */
 817         public function isExternal() {
 818                 return $this->mInterwiki !== '';
 819         }
 820
 821         /**
 822          * Get the interwiki prefix
 823          *
 824          * Use Title::isExternal to check if a interwiki is set
 825          *
 826          * @return string Interwiki prefix
 827          */
 828         public function getInterwiki() {
 829                 return $this->mInterwiki;
 830         }
 831
 832         /**
 833          * Was this a local interwiki link?
 834          *
 835          * @return bool
 836          */
 837         public function wasLocalInterwiki() {
 838                 return $this->mLocalInterwiki;
 839         }
 840
 841         /**
 842          * Determine whether the object refers to a page within
 843          * this project and is transcludable.
 844          *
 845          * @return bool True if this is transcludable
 846          */
 847         public function isTrans() {
 848                 if ( !$this->isExternal() ) {
 849                         return false;
 850                 }
 851
 852                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 853         }
 854
 855         /**
 856          * Returns the DB name of the distant wiki which owns the object.
 857          *
 858          * @return string The DB name
 859          */
 860         public function getTransWikiID() {
 861                 if ( !$this->isExternal() ) {
 862                         return false;
 863                 }
 864
 865                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 866         }
 867
 868         /**
 869          * Get a TitleValue object representing this Title.
 870          *
 871          * @note Not all valid Titles have a corresponding valid TitleValue
 872          * (e.g. TitleValues cannot represent page-local links that have a
 873          * fragment but no title text).
 874          *
 875          * @return TitleValue|null
 876          */
 877         public function getTitleValue() {
 878                 if ( $this->mTitleValue === null ) {
 879                         try {
 880                                 $this->mTitleValue = new TitleValue(
 881                                         $this->getNamespace(),
 882                                         $this->getDBkey(),
 883                                         $this->getFragment() );
 884                         } catch ( InvalidArgumentException $ex ) {
 885                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 886                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 887                         }
 888                 }
 889
 890                 return $this->mTitleValue;
 891         }
 892
 893         /**
 894          * Get the text form (spaces not underscores) of the main part
 895          *
 896          * @return string Main part of the title
 897          */
 898         public function getText() {
 899                 return $this->mTextform;
 900         }
 901
 902         /**
 903          * Get the URL-encoded form of the main part
 904          *
 905          * @return string Main part of the title, URL-encoded
 906          */
 907         public function getPartialURL() {
 908                 return $this->mUrlform;
 909         }
 910
 911         /**
 912          * Get the main part with underscores
 913          *
 914          * @return string Main part of the title, with underscores
 915          */
 916         public function getDBkey() {
 917                 return $this->mDbkeyform;
 918         }
 919
 920         /**
 921          * Get the DB key with the initial letter case as specified by the user
 922          *
 923          * @return string DB key
 924          */
 925         function getUserCaseDBKey() {
 926                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 927                         return $this->mUserCaseDBKey;
 928                 } else {
 929                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 930                         return $this->mDbkeyform;
 931                 }
 932         }
 933
 934         /**
 935          * Get the namespace index, i.e. one of the NS_xxxx constants.
 936          *
 937          * @return int Namespace index
 938          */
 939         public function getNamespace() {
 940                 return $this->mNamespace;
 941         }
 942
 943         /**
 944          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 945          *
 946          * @throws MWException
 947          * @return string Content model id
 948          */
 949         public function getContentModel() {
 950                 if ( !$this->mContentModel ) {
 951                         $linkCache = LinkCache::singleton();
 952                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 953                 }
 954
 955                 if ( !$this->mContentModel ) {
 956                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 957                 }
 958
 959                 if ( !$this->mContentModel ) {
 960                         throw new MWException( 'Failed to determine content model!' );
 961                 }
 962
 963                 return $this->mContentModel;
 964         }
 965
 966         /**
 967          * Convenience method for checking a title's content model name
 968          *
 969          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 970          * @return bool True if $this->getContentModel() == $id
 971          */
 972         public function hasContentModel( $id ) {
 973                 return $this->getContentModel() == $id;
 974         }
 975
 976         /**
 977          * Get the namespace text
 978          *
 979          * @return string Namespace text
 980          */
 981         public function getNsText() {
 982                 if ( $this->isExternal() ) {
 983                         // This probably shouldn't even happen. ohh man, oh yuck.
 984                         // But for interwiki transclusion it sometimes does.
 985                         // Shit. Shit shit shit.
 986                         //
 987                         // Use the canonical namespaces if possible to try to
 988                         // resolve a foreign namespace.
 989                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 990                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 991                         }
 992                 }
 993
 994                 try {
 995                         $formatter = self::getTitleFormatter();
 996                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 997                 } catch ( InvalidArgumentException $ex ) {
 998                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 999                         return false;
1000                 }
1001         }
1002
1003         /**
1004          * Get the namespace text of the subject (rather than talk) page
1005          *
1006          * @return string Namespace text
1007          */
1008         public function getSubjectNsText() {
1009                 global $wgContLang;
1010                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1011         }
1012
1013         /**
1014          * Get the namespace text of the talk page
1015          *
1016          * @return string Namespace text
1017          */
1018         public function getTalkNsText() {
1019                 global $wgContLang;
1020                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1021         }
1022
1023         /**
1024          * Could this title have a corresponding talk page?
1025          *
1026          * @return bool
1027          */
1028         public function canTalk() {
1029                 return MWNamespace::canTalk( $this->mNamespace );
1030         }
1031
1032         /**
1033          * Is this in a namespace that allows actual pages?
1034          *
1035          * @return bool
1036          * @internal note -- uses hardcoded namespace index instead of constants
1037          */
1038         public function canExist() {
1039                 return $this->mNamespace >= NS_MAIN;
1040         }
1041
1042         /**
1043          * Can this title be added to a user's watchlist?
1044          *
1045          * @return bool
1046          */
1047         public function isWatchable() {
1048                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1049         }
1050
1051         /**
1052          * Returns true if this is a special page.
1053          *
1054          * @return bool
1055          */
1056         public function isSpecialPage() {
1057                 return $this->getNamespace() == NS_SPECIAL;
1058         }
1059
1060         /**
1061          * Returns true if this title resolves to the named special page
1062          *
1063          * @param string $name The special page name
1064          * @return bool
1065          */
1066         public function isSpecial( $name ) {
1067                 if ( $this->isSpecialPage() ) {
1068                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1069                         if ( $name == $thisName ) {
1070                                 return true;
1071                         }
1072                 }
1073                 return false;
1074         }
1075
1076         /**
1077          * If the Title refers to a special page alias which is not the local default, resolve
1078          * the alias, and localise the name as necessary.  Otherwise, return $this
1079          *
1080          * @return Title
1081          */
1082         public function fixSpecialName() {
1083                 if ( $this->isSpecialPage() ) {
1084                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1085                         if ( $canonicalName ) {
1086                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1087                                 if ( $localName != $this->mDbkeyform ) {
1088                                         return Title::makeTitle( NS_SPECIAL, $localName );
1089                                 }
1090                         }
1091                 }
1092                 return $this;
1093         }
1094
1095         /**
1096          * Returns true if the title is inside the specified namespace.
1097          *
1098          * Please make use of this instead of comparing to getNamespace()
1099          * This function is much more resistant to changes we may make
1100          * to namespaces than code that makes direct comparisons.
1101          * @param int $ns The namespace
1102          * @return bool
1103          * @since 1.19
1104          */
1105         public function inNamespace( $ns ) {
1106                 return MWNamespace::equals( $this->getNamespace(), $ns );
1107         }
1108
1109         /**
1110          * Returns true if the title is inside one of the specified namespaces.
1111          *
1112          * @param int $namespaces,... The namespaces to check for
1113          * @return bool
1114          * @since 1.19
1115          */
1116         public function inNamespaces( /* ... */ ) {
1117                 $namespaces = func_get_args();
1118                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1119                         $namespaces = $namespaces[0];
1120                 }
1121
1122                 foreach ( $namespaces as $ns ) {
1123                         if ( $this->inNamespace( $ns ) ) {
1124                                 return true;
1125                         }
1126                 }
1127
1128                 return false;
1129         }
1130
1131         /**
1132          * Returns true if the title has the same subject namespace as the
1133          * namespace specified.
1134          * For example this method will take NS_USER and return true if namespace
1135          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1136          * as their subject namespace.
1137          *
1138          * This is MUCH simpler than individually testing for equivalence
1139          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1140          * @since 1.19
1141          * @param int $ns
1142          * @return bool
1143          */
1144         public function hasSubjectNamespace( $ns ) {
1145                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1146         }
1147
1148         /**
1149          * Is this Title in a namespace which contains content?
1150          * In other words, is this a content page, for the purposes of calculating
1151          * statistics, etc?
1152          *
1153          * @return bool
1154          */
1155         public function isContentPage() {
1156                 return MWNamespace::isContent( $this->getNamespace() );
1157         }
1158
1159         /**
1160          * Would anybody with sufficient privileges be able to move this page?
1161          * Some pages just aren't movable.
1162          *
1163          * @return bool
1164          */
1165         public function isMovable() {
1166                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1167                         // Interwiki title or immovable namespace. Hooks don't get to override here
1168                         return false;
1169                 }
1170
1171                 $result = true;
1172                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1173                 return $result;
1174         }
1175
1176         /**
1177          * Is this the mainpage?
1178          * @note Title::newFromText seems to be sufficiently optimized by the title
1179          * cache that we don't need to over-optimize by doing direct comparisons and
1180          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1181          * ends up reporting something differently than $title->isMainPage();
1182          *
1183          * @since 1.18
1184          * @return bool
1185          */
1186         public function isMainPage() {
1187                 return $this->equals( Title::newMainPage() );
1188         }
1189
1190         /**
1191          * Is this a subpage?
1192          *
1193          * @return bool
1194          */
1195         public function isSubpage() {
1196                 return MWNamespace::hasSubpages( $this->mNamespace )
1197                         ? strpos( $this->getText(), '/' ) !== false
1198                         : false;
1199         }
1200
1201         /**
1202          * Is this a conversion table for the LanguageConverter?
1203          *
1204          * @return bool
1205          */
1206         public function isConversionTable() {
1207                 // @todo ConversionTable should become a separate content model.
1208
1209                 return $this->getNamespace() == NS_MEDIAWIKI &&
1210                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1211         }
1212
1213         /**
1214          * Does that page contain wikitext, or it is JS, CSS or whatever?
1215          *
1216          * @return bool
1217          */
1218         public function isWikitextPage() {
1219                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1220         }
1221
1222         /**
1223          * Could this page contain custom CSS or JavaScript for the global UI.
1224          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1225          * or CONTENT_MODEL_JAVASCRIPT.
1226          *
1227          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1228          * for that!
1229          *
1230          * Note that this method should not return true for pages that contain and
1231          * show "inactive" CSS or JS.
1232          *
1233          * @return bool
1234          */
1235         public function isCssOrJsPage() {
1236                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1237                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1238                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1239
1240                 # @note This hook is also called in ContentHandler::getDefaultModel.
1241                 #   It's called here again to make sure hook functions can force this
1242                 #   method to return true even outside the mediawiki namespace.
1243
1244                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
1245
1246                 return $isCssOrJsPage;
1247         }
1248
1249         /**
1250          * Is this a .css or .js subpage of a user page?
1251          * @return bool
1252          */
1253         public function isCssJsSubpage() {
1254                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1255                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1256                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1257         }
1258
1259         /**
1260          * Trim down a .css or .js subpage title to get the corresponding skin name
1261          *
1262          * @return string Containing skin name from .css or .js subpage title
1263          */
1264         public function getSkinFromCssJsSubpage() {
1265                 $subpage = explode( '/', $this->mTextform );
1266                 $subpage = $subpage[count( $subpage ) - 1];
1267                 $lastdot = strrpos( $subpage, '.' );
1268                 if ( $lastdot === false ) {
1269                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1270                 }
1271                 return substr( $subpage, 0, $lastdot );
1272         }
1273
1274         /**
1275          * Is this a .css subpage of a user page?
1276          *
1277          * @return bool
1278          */
1279         public function isCssSubpage() {
1280                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1281                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1282         }
1283
1284         /**
1285          * Is this a .js subpage of a user page?
1286          *
1287          * @return bool
1288          */
1289         public function isJsSubpage() {
1290                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1291                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1292         }
1293
1294         /**
1295          * Is this a talk page of some sort?
1296          *
1297          * @return bool
1298          */
1299         public function isTalkPage() {
1300                 return MWNamespace::isTalk( $this->getNamespace() );
1301         }
1302
1303         /**
1304          * Get a Title object associated with the talk page of this article
1305          *
1306          * @return Title The object for the talk page
1307          */
1308         public function getTalkPage() {
1309                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1310         }
1311
1312         /**
1313          * Get a title object associated with the subject page of this
1314          * talk page
1315          *
1316          * @return Title The object for the subject page
1317          */
1318         public function getSubjectPage() {
1319                 // Is this the same title?
1320                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1321                 if ( $this->getNamespace() == $subjectNS ) {
1322                         return $this;
1323                 }
1324                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1325         }
1326
1327         /**
1328          * Get the default namespace index, for when there is no namespace
1329          *
1330          * @return int Default namespace index
1331          */
1332         public function getDefaultNamespace() {
1333                 return $this->mDefaultNamespace;
1334         }
1335
1336         /**
1337          * Get the Title fragment (i.e.\ the bit after the #) in text form
1338          *
1339          * Use Title::hasFragment to check for a fragment
1340          *
1341          * @return string Title fragment
1342          */
1343         public function getFragment() {
1344                 return $this->mFragment;
1345         }
1346
1347         /**
1348          * Check if a Title fragment is set
1349          *
1350          * @return bool
1351          * @since 1.23
1352          */
1353         public function hasFragment() {
1354                 return $this->mFragment !== '';
1355         }
1356
1357         /**
1358          * Get the fragment in URL form, including the "#" character if there is one
1359          * @return string Fragment in URL form
1360          */
1361         public function getFragmentForURL() {
1362                 if ( !$this->hasFragment() ) {
1363                         return '';
1364                 } else {
1365                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1366                 }
1367         }
1368
1369         /**
1370          * Set the fragment for this title. Removes the first character from the
1371          * specified fragment before setting, so it assumes you're passing it with
1372          * an initial "#".
1373          *
1374          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1375          * Still in active use privately.
1376          *
1377          * @param string $fragment Text
1378          */
1379         public function setFragment( $fragment ) {
1380                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1381         }
1382
1383         /**
1384          * Prefix some arbitrary text with the namespace or interwiki prefix
1385          * of this object
1386          *
1387          * @param string $name The text
1388          * @return string The prefixed text
1389          */
1390         private function prefix( $name ) {
1391                 $p = '';
1392                 if ( $this->isExternal() ) {
1393                         $p = $this->mInterwiki . ':';
1394                 }
1395
1396                 if ( 0 != $this->mNamespace ) {
1397                         $p .= $this->getNsText() . ':';
1398                 }
1399                 return $p . $name;
1400         }
1401
1402         /**
1403          * Get the prefixed database key form
1404          *
1405          * @return string The prefixed title, with underscores and
1406          *  any interwiki and namespace prefixes
1407          */
1408         public function getPrefixedDBkey() {
1409                 $s = $this->prefix( $this->mDbkeyform );
1410                 $s = str_replace( ' ', '_', $s );
1411                 return $s;
1412         }
1413
1414         /**
1415          * Get the prefixed title with spaces.
1416          * This is the form usually used for display
1417          *
1418          * @return string The prefixed title, with spaces
1419          */
1420         public function getPrefixedText() {
1421                 if ( $this->mPrefixedText === null ) {
1422                         $s = $this->prefix( $this->mTextform );
1423                         $s = str_replace( '_', ' ', $s );
1424                         $this->mPrefixedText = $s;
1425                 }
1426                 return $this->mPrefixedText;
1427         }
1428
1429         /**
1430          * Return a string representation of this title
1431          *
1432          * @return string Representation of this title
1433          */
1434         public function __toString() {
1435                 return $this->getPrefixedText();
1436         }
1437
1438         /**
1439          * Get the prefixed title with spaces, plus any fragment
1440          * (part beginning with '#')
1441          *
1442          * @return string The prefixed title, with spaces and the fragment, including '#'
1443          */
1444         public function getFullText() {
1445                 $text = $this->getPrefixedText();
1446                 if ( $this->hasFragment() ) {
1447                         $text .= '#' . $this->getFragment();
1448                 }
1449                 return $text;
1450         }
1451
1452         /**
1453          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1454          *
1455          * @par Example:
1456          * @code
1457          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1458          * # returns: 'Foo'
1459          * @endcode
1460          *
1461          * @return string Root name
1462          * @since 1.20
1463          */
1464         public function getRootText() {
1465                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1466                         return $this->getText();
1467                 }
1468
1469                 return strtok( $this->getText(), '/' );
1470         }
1471
1472         /**
1473          * Get the root page name title, i.e. the leftmost part before any slashes
1474          *
1475          * @par Example:
1476          * @code
1477          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1478          * # returns: Title{User:Foo}
1479          * @endcode
1480          *
1481          * @return Title Root title
1482          * @since 1.20
1483          */
1484         public function getRootTitle() {
1485                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1486         }
1487
1488         /**
1489          * Get the base page name without a namespace, i.e. the part before the subpage name
1490          *
1491          * @par Example:
1492          * @code
1493          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1494          * # returns: 'Foo/Bar'
1495          * @endcode
1496          *
1497          * @return string Base name
1498          */
1499         public function getBaseText() {
1500                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1501                         return $this->getText();
1502                 }
1503
1504                 $parts = explode( '/', $this->getText() );
1505                 # Don't discard the real title if there's no subpage involved
1506                 if ( count( $parts ) > 1 ) {
1507                         unset( $parts[count( $parts ) - 1] );
1508                 }
1509                 return implode( '/', $parts );
1510         }
1511
1512         /**
1513          * Get the base page name title, i.e. the part before the subpage name
1514          *
1515          * @par Example:
1516          * @code
1517          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1518          * # returns: Title{User:Foo/Bar}
1519          * @endcode
1520          *
1521          * @return Title Base title
1522          * @since 1.20
1523          */
1524         public function getBaseTitle() {
1525                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1526         }
1527
1528         /**
1529          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1530          *
1531          * @par Example:
1532          * @code
1533          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1534          * # returns: "Baz"
1535          * @endcode
1536          *
1537          * @return string Subpage name
1538          */
1539         public function getSubpageText() {
1540                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1541                         return $this->mTextform;
1542                 }
1543                 $parts = explode( '/', $this->mTextform );
1544                 return $parts[count( $parts ) - 1];
1545         }
1546
1547         /**
1548          * Get the title for a subpage of the current page
1549          *
1550          * @par Example:
1551          * @code
1552          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1553          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1554          * @endcode
1555          *
1556          * @param string $text The subpage name to add to the title
1557          * @return Title Subpage title
1558          * @since 1.20
1559          */
1560         public function getSubpage( $text ) {
1561                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1562         }
1563
1564         /**
1565          * Get a URL-encoded form of the subpage text
1566          *
1567          * @return string URL-encoded subpage name
1568          */
1569         public function getSubpageUrlForm() {
1570                 $text = $this->getSubpageText();
1571                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1572                 return $text;
1573         }
1574
1575         /**
1576          * Get a URL-encoded title (not an actual URL) including interwiki
1577          *
1578          * @return string The URL-encoded form
1579          */
1580         public function getPrefixedURL() {
1581                 $s = $this->prefix( $this->mDbkeyform );
1582                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1583                 return $s;
1584         }
1585
1586         /**
1587          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1588          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1589          * second argument named variant. This was deprecated in favor
1590          * of passing an array of option with a "variant" key
1591          * Once $query2 is removed for good, this helper can be dropped
1592          * and the wfArrayToCgi moved to getLocalURL();
1593          *
1594          * @since 1.19 (r105919)
1595          * @param array|string $query
1596          * @param bool $query2
1597          * @return string
1598          */
1599         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1600                 if ( $query2 !== false ) {
1601                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1602                                 "method called with a second parameter is deprecated. Add your " .
1603                                 "parameter to an array passed as the first parameter.", "1.19" );
1604                 }
1605                 if ( is_array( $query ) ) {
1606                         $query = wfArrayToCgi( $query );
1607                 }
1608                 if ( $query2 ) {
1609                         if ( is_string( $query2 ) ) {
1610                                 // $query2 is a string, we will consider this to be
1611                                 // a deprecated $variant argument and add it to the query
1612                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1613                         } else {
1614                                 $query2 = wfArrayToCgi( $query2 );
1615                         }
1616                         // If we have $query content add a & to it first
1617                         if ( $query ) {
1618                                 $query .= '&';
1619                         }
1620                         // Now append the queries together
1621                         $query .= $query2;
1622                 }
1623                 return $query;
1624         }
1625
1626         /**
1627          * Get a real URL referring to this title, with interwiki link and
1628          * fragment
1629          *
1630          * @see self::getLocalURL for the arguments.
1631          * @see wfExpandUrl
1632          * @param array|string $query
1633          * @param bool $query2
1634          * @param string $proto Protocol type to use in URL
1635          * @return string The URL
1636          */
1637         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1638                 $query = self::fixUrlQueryArgs( $query, $query2 );
1639
1640                 # Hand off all the decisions on urls to getLocalURL
1641                 $url = $this->getLocalURL( $query );
1642
1643                 # Expand the url to make it a full url. Note that getLocalURL has the
1644                 # potential to output full urls for a variety of reasons, so we use
1645                 # wfExpandUrl instead of simply prepending $wgServer
1646                 $url = wfExpandUrl( $url, $proto );
1647
1648                 # Finally, add the fragment.
1649                 $url .= $this->getFragmentForURL();
1650
1651                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1652                 return $url;
1653         }
1654
1655         /**
1656          * Get a URL with no fragment or server name (relative URL) from a Title object.
1657          * If this page is generated with action=render, however,
1658          * $wgServer is prepended to make an absolute URL.
1659          *
1660          * @see self::getFullURL to always get an absolute URL.
1661          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1662          *  valid to link, locally, to the current Title.
1663          * @see self::newFromText to produce a Title object.
1664          *
1665          * @param string|array $query An optional query string,
1666          *   not used for interwiki links. Can be specified as an associative array as well,
1667          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1668          *   Some query patterns will trigger various shorturl path replacements.
1669          * @param array $query2 An optional secondary query array. This one MUST
1670          *   be an array. If a string is passed it will be interpreted as a deprecated
1671          *   variant argument and urlencoded into a variant= argument.
1672          *   This second query argument will be added to the $query
1673          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1674          *   pair in the first parameter array instead.
1675          *
1676          * @return string String of the URL.
1677          */
1678         public function getLocalURL( $query = '', $query2 = false ) {
1679                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1680
1681                 $query = self::fixUrlQueryArgs( $query, $query2 );
1682
1683                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1684                 if ( $interwiki ) {
1685                         $namespace = $this->getNsText();
1686                         if ( $namespace != '' ) {
1687                                 # Can this actually happen? Interwikis shouldn't be parsed.
1688                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1689                                 $namespace .= ':';
1690                         }
1691                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1692                         $url = wfAppendQuery( $url, $query );
1693                 } else {
1694                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1695                         if ( $query == '' ) {
1696                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1697                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1698                         } else {
1699                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1700                                 $url = false;
1701                                 $matches = array();
1702
1703                                 if ( !empty( $wgActionPaths )
1704                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1705                                 ) {
1706                                         $action = urldecode( $matches[2] );
1707                                         if ( isset( $wgActionPaths[$action] ) ) {
1708                                                 $query = $matches[1];
1709                                                 if ( isset( $matches[4] ) ) {
1710                                                         $query .= $matches[4];
1711                                                 }
1712                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1713                                                 if ( $query != '' ) {
1714                                                         $url = wfAppendQuery( $url, $query );
1715                                                 }
1716                                         }
1717                                 }
1718
1719                                 if ( $url === false
1720                                         && $wgVariantArticlePath
1721                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1722                                         && $this->getPageLanguage()->hasVariants()
1723                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1724                                 ) {
1725                                         $variant = urldecode( $matches[1] );
1726                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1727                                                 // Only do the variant replacement if the given variant is a valid
1728                                                 // variant for the page's language.
1729                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1730                                                 $url = str_replace( '$1', $dbkey, $url );
1731                                         }
1732                                 }
1733
1734                                 if ( $url === false ) {
1735                                         if ( $query == '-' ) {
1736                                                 $query = '';
1737                                         }
1738                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1739                                 }
1740                         }
1741
1742                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1743
1744                         // @todo FIXME: This causes breakage in various places when we
1745                         // actually expected a local URL and end up with dupe prefixes.
1746                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1747                                 $url = $wgServer . $url;
1748                         }
1749                 }
1750                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1751                 return $url;
1752         }
1753
1754         /**
1755          * Get a URL that's the simplest URL that will be valid to link, locally,
1756          * to the current Title.  It includes the fragment, but does not include
1757          * the server unless action=render is used (or the link is external).  If
1758          * there's a fragment but the prefixed text is empty, we just return a link
1759          * to the fragment.
1760          *
1761          * The result obviously should not be URL-escaped, but does need to be
1762          * HTML-escaped if it's being output in HTML.
1763          *
1764          * @param array $query
1765          * @param bool $query2
1766          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1767          * @see self::getLocalURL for the arguments.
1768          * @return string The URL
1769          */
1770         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1771                 wfProfileIn( __METHOD__ );
1772                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1773                         $ret = $this->getFullURL( $query, $query2, $proto );
1774                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1775                         $ret = $this->getFragmentForURL();
1776                 } else {
1777                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1778                 }
1779                 wfProfileOut( __METHOD__ );
1780                 return $ret;
1781         }
1782
1783         /**
1784          * Get the URL form for an internal link.
1785          * - Used in various Squid-related code, in case we have a different
1786          * internal hostname for the server from the exposed one.
1787          *
1788          * This uses $wgInternalServer to qualify the path, or $wgServer
1789          * if $wgInternalServer is not set. If the server variable used is
1790          * protocol-relative, the URL will be expanded to http://
1791          *
1792          * @see self::getLocalURL for the arguments.
1793          * @return string The URL
1794          */
1795         public function getInternalURL( $query = '', $query2 = false ) {
1796                 global $wgInternalServer, $wgServer;
1797                 $query = self::fixUrlQueryArgs( $query, $query2 );
1798                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1799                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1800                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1801                 return $url;
1802         }
1803
1804         /**
1805          * Get the URL for a canonical link, for use in things like IRC and
1806          * e-mail notifications. Uses $wgCanonicalServer and the
1807          * GetCanonicalURL hook.
1808          *
1809          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1810          *
1811          * @see self::getLocalURL for the arguments.
1812          * @return string The URL
1813          * @since 1.18
1814          */
1815         public function getCanonicalURL( $query = '', $query2 = false ) {
1816                 $query = self::fixUrlQueryArgs( $query, $query2 );
1817                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1818                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1819                 return $url;
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 interwiki link
1826          */
1827         public function getEditURL() {
1828                 if ( $this->isExternal() ) {
1829                         return '';
1830                 }
1831                 $s = $this->getLocalURL( 'action=edit' );
1832
1833                 return $s;
1834         }
1835
1836         /**
1837          * Is $wgUser watching this page?
1838          *
1839          * @deprecated since 1.20; use User::isWatched() instead.
1840          * @return bool
1841          */
1842         public function userIsWatching() {
1843                 global $wgUser;
1844
1845                 if ( is_null( $this->mWatched ) ) {
1846                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1847                                 $this->mWatched = false;
1848                         } else {
1849                                 $this->mWatched = $wgUser->isWatched( $this );
1850                         }
1851                 }
1852                 return $this->mWatched;
1853         }
1854
1855         /**
1856          * Can $user perform $action on this page?
1857          * This skips potentially expensive cascading permission checks
1858          * as well as avoids expensive error formatting
1859          *
1860          * Suitable for use for nonessential UI controls in common cases, but
1861          * _not_ for functional access control.
1862          *
1863          * May provide false positives, but should never provide a false negative.
1864          *
1865          * @param string $action Action that permission needs to be checked for
1866          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1867          * @return bool
1868          */
1869         public function quickUserCan( $action, $user = null ) {
1870                 return $this->userCan( $action, $user, false );
1871         }
1872
1873         /**
1874          * Can $user perform $action on this page?
1875          *
1876          * @param string $action Action that permission needs to be checked for
1877          * @param User $user User to check (since 1.19); $wgUser will be used if not
1878          *   provided.
1879          * @param bool $doExpensiveQueries Set this to false to avoid doing
1880          *   unnecessary queries.
1881          * @return bool
1882          */
1883         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1884                 if ( !$user instanceof User ) {
1885                         global $wgUser;
1886                         $user = $wgUser;
1887                 }
1888
1889                 return !count( $this->getUserPermissionsErrorsInternal(
1890                         $action, $user, $doExpensiveQueries, true ) );
1891         }
1892
1893         /**
1894          * Can $user perform $action on this page?
1895          *
1896          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1897          *
1898          * @param string $action Action that permission needs to be checked for
1899          * @param User $user User to check
1900          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1901          *   queries by skipping checks for cascading protections and user blocks.
1902          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1903          *   whose corresponding errors may be ignored.
1904          * @return array Array of arguments to wfMessage to explain permissions problems.
1905          */
1906         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true,
1907                 $ignoreErrors = array()
1908         ) {
1909                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1910
1911                 // Remove the errors being ignored.
1912                 foreach ( $errors as $index => $error ) {
1913                         $error_key = is_array( $error ) ? $error[0] : $error;
1914
1915                         if ( in_array( $error_key, $ignoreErrors ) ) {
1916                                 unset( $errors[$index] );
1917                         }
1918                 }
1919
1920                 return $errors;
1921         }
1922
1923         /**
1924          * Permissions checks that fail most often, and which are easiest to test.
1925          *
1926          * @param string $action The action to check
1927          * @param User $user User to check
1928          * @param array $errors List of current errors
1929          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
1930          * @param bool $short Short circuit on first error
1931          *
1932          * @return array List of errors
1933          */
1934         private function checkQuickPermissions( $action, $user, $errors,
1935                 $doExpensiveQueries, $short
1936         ) {
1937                 if ( !wfRunHooks( 'TitleQuickPermissions',
1938                         array( $this, $user, $action, &$errors, $doExpensiveQueries, $short ) )
1939                 ) {
1940                         return $errors;
1941                 }
1942
1943                 if ( $action == 'create' ) {
1944                         if (
1945                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1946                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1947                         ) {
1948                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1949                         }
1950                 } elseif ( $action == 'move' ) {
1951                         if ( !$user->isAllowed( 'move-rootuserpages' )
1952                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1953                                 // Show user page-specific message only if the user can move other pages
1954                                 $errors[] = array( 'cant-move-user-page' );
1955                         }
1956
1957                         // Check if user is allowed to move files if it's a file
1958                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1959                                 $errors[] = array( 'movenotallowedfile' );
1960                         }
1961
1962                         // Check if user is allowed to move category pages if it's a category page
1963                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1964                                 $errors[] = array( 'cant-move-category-page' );
1965                         }
1966
1967                         if ( !$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                                 $errors[] = array( 'cant-move-to-user-page' );
1986                         } elseif ( !$user->isAllowed( 'move-categorypages' )
1987                                         && $this->mNamespace == NS_CATEGORY ) {
1988                                 // Show category page-specific message only if the user can move other pages
1989                                 $errors[] = array( 'cant-move-to-category-page' );
1990                         }
1991                 } elseif ( !$user->isAllowed( $action ) ) {
1992                         $errors[] = $this->missingPermissionError( $action, $short );
1993                 }
1994
1995                 return $errors;
1996         }
1997
1998         /**
1999          * Add the resulting error code to the errors array
2000          *
2001          * @param array $errors List of current errors
2002          * @param array $result Result of errors
2003          *
2004          * @return array List of errors
2005          */
2006         private function resultToError( $errors, $result ) {
2007                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2008                         // A single array representing an error
2009                         $errors[] = $result;
2010                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2011                         // A nested array representing multiple errors
2012                         $errors = array_merge( $errors, $result );
2013                 } elseif ( $result !== '' && is_string( $result ) ) {
2014                         // A string representing a message-id
2015                         $errors[] = array( $result );
2016                 } elseif ( $result === false ) {
2017                         // a generic "We don't want them to do that"
2018                         $errors[] = array( 'badaccess-group0' );
2019                 }
2020                 return $errors;
2021         }
2022
2023         /**
2024          * Check various permission hooks
2025          *
2026          * @param string $action The action to check
2027          * @param User $user User to check
2028          * @param array $errors List of current errors
2029          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2030          * @param bool $short Short circuit on first error
2031          *
2032          * @return array List of errors
2033          */
2034         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
2035                 // Use getUserPermissionsErrors instead
2036                 $result = '';
2037                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
2038                         return $result ? array() : array( array( 'badaccess-group0' ) );
2039                 }
2040                 // Check getUserPermissionsErrors hook
2041                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
2042                         $errors = $this->resultToError( $errors, $result );
2043                 }
2044                 // Check getUserPermissionsErrorsExpensive hook
2045                 if (
2046                         $doExpensiveQueries
2047                         && !( $short && count( $errors ) > 0 )
2048                         && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
2049                 ) {
2050                         $errors = $this->resultToError( $errors, $result );
2051                 }
2052
2053                 return $errors;
2054         }
2055
2056         /**
2057          * Check permissions on special pages & namespaces
2058          *
2059          * @param string $action The action to check
2060          * @param User $user User to check
2061          * @param array $errors List of current errors
2062          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2063          * @param bool $short Short circuit on first error
2064          *
2065          * @return array List of errors
2066          */
2067         private function checkSpecialsAndNSPermissions( $action, $user, $errors,
2068                 $doExpensiveQueries, $short
2069         ) {
2070                 # Only 'createaccount' can be performed on special pages,
2071                 # which don't actually exist in the DB.
2072                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2073                         $errors[] = array( 'ns-specialprotected' );
2074                 }
2075
2076                 # Check $wgNamespaceProtection for restricted namespaces
2077                 if ( $this->isNamespaceProtected( $user ) ) {
2078                         $ns = $this->mNamespace == NS_MAIN ?
2079                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2080                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2081                                 array( 'protectedinterface', $action ) : array( 'namespaceprotected', $ns, $action );
2082                 }
2083
2084                 return $errors;
2085         }
2086
2087         /**
2088          * Check CSS/JS sub-page permissions
2089          *
2090          * @param string $action The action to check
2091          * @param User $user User to check
2092          * @param array $errors List of current errors
2093          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2094          * @param bool $short Short circuit on first error
2095          *
2096          * @return array List of errors
2097          */
2098         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2099                 # Protect css/js subpages of user pages
2100                 # XXX: this might be better using restrictions
2101                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2102                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2103                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2104                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2105                                         $errors[] = array( 'mycustomcssprotected', $action );
2106                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2107                                         $errors[] = array( 'mycustomjsprotected', $action );
2108                                 }
2109                         } else {
2110                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2111                                         $errors[] = array( 'customcssprotected', $action );
2112                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2113                                         $errors[] = array( 'customjsprotected', $action );
2114                                 }
2115                         }
2116                 }
2117
2118                 return $errors;
2119         }
2120
2121         /**
2122          * Check against page_restrictions table requirements on this
2123          * page. The user must possess all required rights for this
2124          * action.
2125          *
2126          * @param string $action The action to check
2127          * @param User $user User to check
2128          * @param array $errors List of current errors
2129          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2130          * @param bool $short Short circuit on first error
2131          *
2132          * @return array List of errors
2133          */
2134         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2135                 foreach ( $this->getRestrictions( $action ) as $right ) {
2136                         // Backwards compatibility, rewrite sysop -> editprotected
2137                         if ( $right == 'sysop' ) {
2138                                 $right = 'editprotected';
2139                         }
2140                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2141                         if ( $right == 'autoconfirmed' ) {
2142                                 $right = 'editsemiprotected';
2143                         }
2144                         if ( $right == '' ) {
2145                                 continue;
2146                         }
2147                         if ( !$user->isAllowed( $right ) ) {
2148                                 $errors[] = array( 'protectedpagetext', $right, $action );
2149                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2150                                 $errors[] = array( 'protectedpagetext', 'protect', $action );
2151                         }
2152                 }
2153
2154                 return $errors;
2155         }
2156
2157         /**
2158          * Check restrictions on cascading pages.
2159          *
2160          * @param string $action The action to check
2161          * @param User $user User to check
2162          * @param array $errors List of current errors
2163          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2164          * @param bool $short Short circuit on first error
2165          *
2166          * @return array List of errors
2167          */
2168         private function checkCascadingSourcesRestrictions( $action, $user, $errors,
2169                 $doExpensiveQueries, $short
2170         ) {
2171                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
2172                         # We /could/ use the protection level on the source page, but it's
2173                         # fairly ugly as we have to establish a precedence hierarchy for pages
2174                         # included by multiple cascade-protected pages. So just restrict
2175                         # it to people with 'protect' permission, as they could remove the
2176                         # protection anyway.
2177                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2178                         # Cascading protection depends on more than this page...
2179                         # Several cascading protected pages may include this page...
2180                         # Check each cascading level
2181                         # This is only for protection restrictions, not for all actions
2182                         if ( isset( $restrictions[$action] ) ) {
2183                                 foreach ( $restrictions[$action] as $right ) {
2184                                         // Backwards compatibility, rewrite sysop -> editprotected
2185                                         if ( $right == 'sysop' ) {
2186                                                 $right = 'editprotected';
2187                                         }
2188                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2189                                         if ( $right == 'autoconfirmed' ) {
2190                                                 $right = 'editsemiprotected';
2191                                         }
2192                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2193                                                 $pages = '';
2194                                                 foreach ( $cascadingSources as $page ) {
2195                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2196                                                 }
2197                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages, $action );
2198                                         }
2199                                 }
2200                         }
2201                 }
2202
2203                 return $errors;
2204         }
2205
2206         /**
2207          * Check action permissions not already checked in checkQuickPermissions
2208          *
2209          * @param string $action The action to check
2210          * @param User $user User to check
2211          * @param array $errors List of current errors
2212          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2213          * @param bool $short Short circuit on first error
2214          *
2215          * @return array List of errors
2216          */
2217         private function checkActionPermissions( $action, $user, $errors,
2218                 $doExpensiveQueries, $short
2219         ) {
2220                 global $wgDeleteRevisionsLimit, $wgLang;
2221
2222                 if ( $action == 'protect' ) {
2223                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit',
2224                                 $user, $doExpensiveQueries, true ) )
2225                         ) {
2226                                 // If they can't edit, they shouldn't protect.
2227                                 $errors[] = array( 'protect-cantedit' );
2228                         }
2229                 } elseif ( $action == 'create' ) {
2230                         $title_protection = $this->getTitleProtection();
2231                         if ( $title_protection ) {
2232                                 if ( $title_protection['pt_create_perm'] == 'sysop' ) {
2233                                         $title_protection['pt_create_perm'] = 'editprotected'; // B/C
2234                                 }
2235                                 if ( $title_protection['pt_create_perm'] == 'autoconfirmed' ) {
2236                                         $title_protection['pt_create_perm'] = 'editsemiprotected'; // B/C
2237                                 }
2238                                 if ( $title_protection['pt_create_perm'] == ''
2239                                         || !$user->isAllowed( $title_protection['pt_create_perm'] )
2240                                 ) {
2241                                         $errors[] = array(
2242                                                 'titleprotected',
2243                                                 User::whoIs( $title_protection['pt_user'] ),
2244                                                 $title_protection['pt_reason']
2245                                         );
2246                                 }
2247                         }
2248                 } elseif ( $action == 'move' ) {
2249                         // Check for immobile pages
2250                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2251                                 // Specific message for this case
2252                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2253                         } elseif ( !$this->isMovable() ) {
2254                                 // Less specific message for rarer cases
2255                                 $errors[] = array( 'immobile-source-page' );
2256                         }
2257                 } elseif ( $action == 'move-target' ) {
2258                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2259                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2260                         } elseif ( !$this->isMovable() ) {
2261                                 $errors[] = array( 'immobile-target-page' );
2262                         }
2263                 } elseif ( $action == 'delete' ) {
2264                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit',
2265                                 $user, $doExpensiveQueries, true ) )
2266                         ) {
2267                                 // If they can't edit, they shouldn't delete.
2268                                 $errors[] = array( 'delete-cantedit' );
2269                         }
2270                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2271                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2272                         ) {
2273                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2274                         }
2275                 }
2276                 return $errors;
2277         }
2278
2279         /**
2280          * Check that the user isn't blocked from editing.
2281          *
2282          * @param string $action The action to check
2283          * @param User $user User to check
2284          * @param array $errors List of current errors
2285          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2286          * @param bool $short Short circuit on first error
2287          *
2288          * @return array List of errors
2289          */
2290         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2291                 // Account creation blocks handled at userlogin.
2292                 // Unblocking handled in SpecialUnblock
2293                 if ( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2294                         return $errors;
2295                 }
2296
2297                 global $wgEmailConfirmToEdit;
2298
2299                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2300                         $errors[] = array( 'confirmedittext' );
2301                 }
2302
2303                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2304                         // Don't block the user from editing their own talk page unless they've been
2305                         // explicitly blocked from that too.
2306                 } elseif ( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2307                         // @todo FIXME: Pass the relevant context into this function.
2308                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2309                 }
2310
2311                 return $errors;
2312         }
2313
2314         /**
2315          * Check that the user is allowed to read this page.
2316          *
2317          * @param string $action The action to check
2318          * @param User $user User to check
2319          * @param array $errors List of current errors
2320          * @param bool $doExpensiveQueries Whether or not to perform expensive queries
2321          * @param bool $short Short circuit on first error
2322          *
2323          * @return array List of errors
2324          */
2325         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2326                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2327
2328                 $whitelisted = false;
2329                 if ( User::isEveryoneAllowed( 'read' ) ) {
2330                         # Shortcut for public wikis, allows skipping quite a bit of code
2331                         $whitelisted = true;
2332                 } elseif ( $user->isAllowed( 'read' ) ) {
2333                         # If the user is allowed to read pages, he is allowed to read all pages
2334                         $whitelisted = true;
2335                 } elseif ( $this->isSpecial( 'Userlogin' )
2336                         || $this->isSpecial( 'ChangePassword' )
2337                         || $this->isSpecial( 'PasswordReset' )
2338                 ) {
2339                         # Always grant access to the login page.
2340                         # Even anons need to be able to log in.
2341                         $whitelisted = true;
2342                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2343                         # Time to check the whitelist
2344                         # Only do these checks is there's something to check against
2345                         $name = $this->getPrefixedText();
2346                         $dbName = $this->getPrefixedDBkey();
2347
2348                         // Check for explicit whitelisting with and without underscores
2349                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2350                                 $whitelisted = true;
2351                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2352                                 # Old settings might have the title prefixed with
2353                                 # a colon for main-namespace pages
2354                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2355                                         $whitelisted = true;
2356                                 }
2357                         } elseif ( $this->isSpecialPage() ) {
2358                                 # If it's a special page, ditch the subpage bit and check again
2359                                 $name = $this->getDBkey();
2360                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2361                                 if ( $name ) {
2362                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2363                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2364                                                 $whitelisted = true;
2365                                         }
2366                                 }
2367                         }
2368                 }
2369
2370                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2371                         $name = $this->getPrefixedText();
2372                         // Check for regex whitelisting
2373                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2374                                 if ( preg_match( $listItem, $name ) ) {
2375                                         $whitelisted = true;
2376                                         break;
2377                                 }
2378                         }
2379                 }
2380
2381                 if ( !$whitelisted ) {
2382                         # If the title is not whitelisted, give extensions a chance to do so...
2383                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2384                         if ( !$whitelisted ) {
2385                                 $errors[] = $this->missingPermissionError( $action, $short );
2386                         }
2387                 }
2388
2389                 return $errors;
2390         }
2391
2392         /**
2393          * Get a description array when the user doesn't have the right to perform
2394          * $action (i.e. when User::isAllowed() returns false)
2395          *
2396          * @param string $action The action to check
2397          * @param bool $short Short circuit on first error
2398          * @return array List of errors
2399          */
2400         private function missingPermissionError( $action, $short ) {
2401                 // We avoid expensive display logic for quickUserCan's and such
2402                 if ( $short ) {
2403                         return array( 'badaccess-group0' );
2404                 }
2405
2406                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2407                         User::getGroupsWithPermission( $action ) );
2408
2409                 if ( count( $groups ) ) {
2410                         global $wgLang;
2411                         return array(
2412                                 'badaccess-groups',
2413                                 $wgLang->commaList( $groups ),
2414                                 count( $groups )
2415                         );
2416                 } else {
2417                         return array( 'badaccess-group0' );
2418                 }
2419         }
2420
2421         /**
2422          * Can $user perform $action on this page? This is an internal function,
2423          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2424          * checks on wfReadOnly() and blocks)
2425          *
2426          * @param string $action Action that permission needs to be checked for
2427          * @param User $user User to check
2428          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
2429          * @param bool $short Set this to true to stop after the first permission error.
2430          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2431          */
2432         protected function getUserPermissionsErrorsInternal( $action, $user,
2433                 $doExpensiveQueries = true, $short = false
2434         ) {
2435                 wfProfileIn( __METHOD__ );
2436
2437                 # Read has special handling
2438                 if ( $action == 'read' ) {
2439                         $checks = array(
2440                                 'checkPermissionHooks',
2441                                 'checkReadPermissions',
2442                         );
2443                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2444                 # here as it will lead to duplicate error messages. This is okay to do
2445                 # since anywhere that checks for create will also check for edit, and
2446                 # those checks are called for edit.
2447                 } elseif ( $action == 'create' ) {
2448                         $checks = array(
2449                                 'checkQuickPermissions',
2450                                 'checkPermissionHooks',
2451                                 'checkPageRestrictions',
2452                                 'checkCascadingSourcesRestrictions',
2453                                 'checkActionPermissions',
2454                                 'checkUserBlock'
2455                         );
2456                 } else {
2457                         $checks = array(
2458                                 'checkQuickPermissions',
2459                                 'checkPermissionHooks',
2460                                 'checkSpecialsAndNSPermissions',
2461                                 'checkCSSandJSPermissions',
2462                                 'checkPageRestrictions',
2463                                 'checkCascadingSourcesRestrictions',
2464                                 'checkActionPermissions',
2465                                 'checkUserBlock'
2466                         );
2467                 }
2468
2469                 $errors = array();
2470                 while ( count( $checks ) > 0 &&
2471                                 !( $short && count( $errors ) > 0 ) ) {
2472                         $method = array_shift( $checks );
2473                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2474                 }
2475
2476                 wfProfileOut( __METHOD__ );
2477                 return $errors;
2478         }
2479
2480         /**
2481          * Get a filtered list of all restriction types supported by this wiki.
2482          * @param bool $exists True to get all restriction types that apply to
2483          * titles that do exist, False for all restriction types that apply to
2484          * titles that do not exist
2485          * @return array
2486          */
2487         public static function getFilteredRestrictionTypes( $exists = true ) {
2488                 global $wgRestrictionTypes;
2489                 $types = $wgRestrictionTypes;
2490                 if ( $exists ) {
2491                         # Remove the create restriction for existing titles
2492                         $types = array_diff( $types, array( 'create' ) );
2493                 } else {
2494                         # Only the create and upload restrictions apply to non-existing titles
2495                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2496                 }
2497                 return $types;
2498         }
2499
2500         /**
2501          * Returns restriction types for the current Title
2502          *
2503          * @return array Applicable restriction types
2504          */
2505         public function getRestrictionTypes() {
2506                 if ( $this->isSpecialPage() ) {
2507                         return array();
2508                 }
2509
2510                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2511
2512                 if ( $this->getNamespace() != NS_FILE ) {
2513                         # Remove the upload restriction for non-file titles
2514                         $types = array_diff( $types, array( 'upload' ) );
2515                 }
2516
2517                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2518
2519                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2520                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2521
2522                 return $types;
2523         }
2524
2525         /**
2526          * Is this title subject to title protection?
2527          * Title protection is the one applied against creation of such title.
2528          *
2529          * @return array|bool An associative array representing any existent title
2530          *   protection, or false if there's none.
2531          */
2532         private function getTitleProtection() {
2533                 // Can't protect pages in special namespaces
2534                 if ( $this->getNamespace() < 0 ) {
2535                         return false;
2536                 }
2537
2538                 // Can't protect pages that exist.
2539                 if ( $this->exists() ) {
2540                         return false;
2541                 }
2542
2543                 if ( $this->mTitleProtection === null ) {
2544                         $dbr = wfGetDB( DB_SLAVE );
2545                         $res = $dbr->select(
2546                                 'protected_titles',
2547                                 array( 'pt_user', 'pt_reason', 'pt_expiry', 'pt_create_perm' ),
2548                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2549                                 __METHOD__
2550                         );
2551
2552                         // fetchRow returns false if there are no rows.
2553                         $this->mTitleProtection = $dbr->fetchRow( $res );
2554                 }
2555                 return $this->mTitleProtection;
2556         }
2557
2558         /**
2559          * Remove any title protection due to page existing
2560          */
2561         public function deleteTitleProtection() {
2562                 $dbw = wfGetDB( DB_MASTER );
2563
2564                 $dbw->delete(
2565                         'protected_titles',
2566                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2567                         __METHOD__
2568                 );
2569                 $this->mTitleProtection = false;
2570         }
2571
2572         /**
2573          * Is this page "semi-protected" - the *only* protection levels are listed
2574          * in $wgSemiprotectedRestrictionLevels?
2575          *
2576          * @param string $action Action to check (default: edit)
2577          * @return bool
2578          */
2579         public function isSemiProtected( $action = 'edit' ) {
2580                 global $wgSemiprotectedRestrictionLevels;
2581
2582                 $restrictions = $this->getRestrictions( $action );
2583                 $semi = $wgSemiprotectedRestrictionLevels;
2584                 if ( !$restrictions || !$semi ) {
2585                         // Not protected, or all protection is full protection
2586                         return false;
2587                 }
2588
2589                 // Remap autoconfirmed to editsemiprotected for BC
2590                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2591                         $semi[$key] = 'editsemiprotected';
2592                 }
2593                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2594                         $restrictions[$key] = 'editsemiprotected';
2595                 }
2596
2597                 return !array_diff( $restrictions, $semi );
2598         }
2599
2600         /**
2601          * Does the title correspond to a protected article?
2602          *
2603          * @param string $action The action the page is protected from,
2604          * by default checks all actions.
2605          * @return bool
2606          */
2607         public function isProtected( $action = '' ) {
2608                 global $wgRestrictionLevels;
2609
2610                 $restrictionTypes = $this->getRestrictionTypes();
2611
2612                 # Special pages have inherent protection
2613                 if ( $this->isSpecialPage() ) {
2614                         return true;
2615                 }
2616
2617                 # Check regular protection levels
2618                 foreach ( $restrictionTypes as $type ) {
2619                         if ( $action == $type || $action == '' ) {
2620                                 $r = $this->getRestrictions( $type );
2621                                 foreach ( $wgRestrictionLevels as $level ) {
2622                                         if ( in_array( $level, $r ) && $level != '' ) {
2623                                                 return true;
2624                                         }
2625                                 }
2626                         }
2627                 }
2628
2629                 return false;
2630         }
2631
2632         /**
2633          * Determines if $user is unable to edit this page because it has been protected
2634          * by $wgNamespaceProtection.
2635          *
2636          * @param User $user User object to check permissions
2637          * @return bool
2638          */
2639         public function isNamespaceProtected( User $user ) {
2640                 global $wgNamespaceProtection;
2641
2642                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2643                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2644                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2645                                         return true;
2646                                 }
2647                         }
2648                 }
2649                 return false;
2650         }
2651
2652         /**
2653          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2654          *
2655          * @return bool If the page is subject to cascading restrictions.
2656          */
2657         public function isCascadeProtected() {
2658                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2659                 return ( $sources > 0 );
2660         }
2661
2662         /**
2663          * Determines whether cascading protection sources have already been loaded from
2664          * the database.
2665          *
2666          * @param bool $getPages True to check if the pages are loaded, or false to check
2667          * if the status is loaded.
2668          * @return bool Whether or not the specified information has been loaded
2669          * @since 1.23
2670          */
2671         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2672                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2673         }
2674
2675         /**
2676          * Cascading protection: Get the source of any cascading restrictions on this page.
2677          *
2678          * @param bool $getPages Whether or not to retrieve the actual pages
2679          *        that the restrictions have come from and the actual restrictions
2680          *        themselves.
2681          * @return array Two elements: First is an array of Title objects of the
2682          *        pages from which cascading restrictions have come, false for
2683          *        none, or true if such restrictions exist but $getPages was not
2684          *        set. Second is an array like that returned by
2685          *        Title::getAllRestrictions(), or an empty array if $getPages is
2686          *        false.
2687          */
2688         public function getCascadeProtectionSources( $getPages = true ) {
2689                 global $wgContLang;
2690                 $pagerestrictions = array();
2691
2692                 if ( $this->mCascadeSources !== null && $getPages ) {
2693                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2694                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2695                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2696                 }
2697
2698                 wfProfileIn( __METHOD__ );
2699
2700                 $dbr = wfGetDB( DB_SLAVE );
2701
2702                 if ( $this->getNamespace() == NS_FILE ) {
2703                         $tables = array( 'imagelinks', 'page_restrictions' );
2704                         $where_clauses = array(
2705                                 'il_to' => $this->getDBkey(),
2706                                 'il_from=pr_page',
2707                                 'pr_cascade' => 1
2708                         );
2709                 } else {
2710                         $tables = array( 'templatelinks', 'page_restrictions' );
2711                         $where_clauses = array(
2712                                 'tl_namespace' => $this->getNamespace(),
2713                                 'tl_title' => $this->getDBkey(),
2714                                 'tl_from=pr_page',
2715                                 'pr_cascade' => 1
2716                         );
2717                 }
2718
2719                 if ( $getPages ) {
2720                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2721                                 'pr_expiry', 'pr_type', 'pr_level' );
2722                         $where_clauses[] = 'page_id=pr_page';
2723                         $tables[] = 'page';
2724                 } else {
2725                         $cols = array( 'pr_expiry' );
2726                 }
2727
2728                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2729
2730                 $sources = $getPages ? array() : false;
2731                 $now = wfTimestampNow();
2732                 $purgeExpired = false;
2733
2734                 foreach ( $res as $row ) {
2735                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2736                         if ( $expiry > $now ) {
2737                                 if ( $getPages ) {
2738                                         $page_id = $row->pr_page;
2739                                         $page_ns = $row->page_namespace;
2740                                         $page_title = $row->page_title;
2741                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2742                                         # Add groups needed for each restriction type if its not already there
2743                                         # Make sure this restriction type still exists
2744
2745                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2746                                                 $pagerestrictions[$row->pr_type] = array();
2747                                         }
2748
2749                                         if (
2750                                                 isset( $pagerestrictions[$row->pr_type] )
2751                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2752                                         ) {
2753                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2754                                         }
2755                                 } else {
2756                                         $sources = true;
2757                                 }
2758                         } else {
2759                                 // Trigger lazy purge of expired restrictions from the db
2760                                 $purgeExpired = true;
2761                         }
2762                 }
2763                 if ( $purgeExpired ) {
2764                         Title::purgeExpiredRestrictions();
2765                 }
2766
2767                 if ( $getPages ) {
2768                         $this->mCascadeSources = $sources;
2769                         $this->mCascadingRestrictions = $pagerestrictions;
2770                 } else {
2771                         $this->mHasCascadingRestrictions = $sources;
2772                 }
2773
2774                 wfProfileOut( __METHOD__ );
2775                 return array( $sources, $pagerestrictions );
2776         }
2777
2778         /**
2779          * Accessor for mRestrictionsLoaded
2780          *
2781          * @return bool Whether or not the page's restrictions have already been
2782          * loaded from the database
2783          * @since 1.23
2784          */
2785         public function areRestrictionsLoaded() {
2786                 return $this->mRestrictionsLoaded;
2787         }
2788
2789         /**
2790          * Accessor/initialisation for mRestrictions
2791          *
2792          * @param string $action Action that permission needs to be checked for
2793          * @return array Restriction levels needed to take the action. All levels
2794          *     are required.
2795          */
2796         public function getRestrictions( $action ) {
2797                 if ( !$this->mRestrictionsLoaded ) {
2798                         $this->loadRestrictions();
2799                 }
2800                 return isset( $this->mRestrictions[$action] )
2801                                 ? $this->mRestrictions[$action]
2802                                 : array();
2803         }
2804
2805         /**
2806          * Accessor/initialisation for mRestrictions
2807          *
2808          * @return array Keys are actions, values are arrays as returned by
2809          *     Title::getRestrictions()
2810          * @since 1.23
2811          */
2812         public function getAllRestrictions() {
2813                 if ( !$this->mRestrictionsLoaded ) {
2814                         $this->loadRestrictions();
2815                 }
2816                 return $this->mRestrictions;
2817         }
2818
2819         /**
2820          * Get the expiry time for the restriction against a given action
2821          *
2822          * @param string $action
2823          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2824          *     or not protected at all, or false if the action is not recognised.
2825          */
2826         public function getRestrictionExpiry( $action ) {
2827                 if ( !$this->mRestrictionsLoaded ) {
2828                         $this->loadRestrictions();
2829                 }
2830                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2831         }
2832
2833         /**
2834          * Returns cascading restrictions for the current article
2835          *
2836          * @return bool
2837          */
2838         function areRestrictionsCascading() {
2839                 if ( !$this->mRestrictionsLoaded ) {
2840                         $this->loadRestrictions();
2841                 }
2842
2843                 return $this->mCascadeRestriction;
2844         }
2845
2846         /**
2847          * Loads a string into mRestrictions array
2848          *
2849          * @param ResultWrapper $res Resource restrictions as an SQL result.
2850          * @param string $oldFashionedRestrictions Comma-separated list of page
2851          *        restrictions from page table (pre 1.10)
2852          */
2853         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2854                 $rows = array();
2855
2856                 foreach ( $res as $row ) {
2857                         $rows[] = $row;
2858                 }
2859
2860                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2861         }
2862
2863         /**
2864          * Compiles list of active page restrictions from both page table (pre 1.10)
2865          * and page_restrictions table for this existing page.
2866          * Public for usage by LiquidThreads.
2867          *
2868          * @param array $rows Array of db result objects
2869          * @param string $oldFashionedRestrictions Comma-separated list of page
2870          *   restrictions from page table (pre 1.10)
2871          */
2872         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2873                 global $wgContLang;
2874                 $dbr = wfGetDB( DB_SLAVE );
2875
2876                 $restrictionTypes = $this->getRestrictionTypes();
2877
2878                 foreach ( $restrictionTypes as $type ) {
2879                         $this->mRestrictions[$type] = array();
2880                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2881                 }
2882
2883                 $this->mCascadeRestriction = false;
2884
2885                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2886
2887                 if ( $oldFashionedRestrictions === null ) {
2888                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2889                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2890                 }
2891
2892                 if ( $oldFashionedRestrictions != '' ) {
2893
2894                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2895                                 $temp = explode( '=', trim( $restrict ) );
2896                                 if ( count( $temp ) == 1 ) {
2897                                         // old old format should be treated as edit/move restriction
2898                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2899                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2900                                 } else {
2901                                         $restriction = trim( $temp[1] );
2902                                         if ( $restriction != '' ) { //some old entries are empty
2903                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2904                                         }
2905                                 }
2906                         }
2907
2908                         $this->mOldRestrictions = true;
2909
2910                 }
2911
2912                 if ( count( $rows ) ) {
2913                         # Current system - load second to make them override.
2914                         $now = wfTimestampNow();
2915                         $purgeExpired = false;
2916
2917                         # Cycle through all the restrictions.
2918                         foreach ( $rows as $row ) {
2919
2920                                 // Don't take care of restrictions types that aren't allowed
2921                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2922                                         continue;
2923                                 }
2924
2925                                 // This code should be refactored, now that it's being used more generally,
2926                                 // But I don't really see any harm in leaving it in Block for now -werdna
2927                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2928
2929                                 // Only apply the restrictions if they haven't expired!
2930                                 if ( !$expiry || $expiry > $now ) {
2931                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2932                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2933
2934                                         $this->mCascadeRestriction |= $row->pr_cascade;
2935                                 } else {
2936                                         // Trigger a lazy purge of expired restrictions
2937                                         $purgeExpired = true;
2938                                 }
2939                         }
2940
2941                         if ( $purgeExpired ) {
2942                                 Title::purgeExpiredRestrictions();
2943                         }
2944                 }
2945
2946                 $this->mRestrictionsLoaded = true;
2947         }
2948
2949         /**
2950          * Load restrictions from the page_restrictions table
2951          *
2952          * @param string $oldFashionedRestrictions Comma-separated list of page
2953          *   restrictions from page table (pre 1.10)
2954          */
2955         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2956                 global $wgContLang;
2957                 if ( !$this->mRestrictionsLoaded ) {
2958                         if ( $this->exists() ) {
2959                                 $dbr = wfGetDB( DB_SLAVE );
2960
2961                                 $res = $dbr->select(
2962                                         'page_restrictions',
2963                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2964                                         array( 'pr_page' => $this->getArticleID() ),
2965                                         __METHOD__
2966                                 );
2967
2968                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2969                         } else {
2970                                 $title_protection = $this->getTitleProtection();
2971
2972                                 if ( $title_protection ) {
2973                                         $now = wfTimestampNow();
2974                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2975
2976                                         if ( !$expiry || $expiry > $now ) {
2977                                                 // Apply the restrictions
2978                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2979                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2980                                         } else { // Get rid of the old restrictions
2981                                                 Title::purgeExpiredRestrictions();
2982                                                 $this->mTitleProtection = false;
2983                                         }
2984                                 } else {
2985                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2986                                 }
2987                                 $this->mRestrictionsLoaded = true;
2988                         }
2989                 }
2990         }
2991
2992         /**
2993          * Flush the protection cache in this object and force reload from the database.
2994          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2995          */
2996         public function flushRestrictions() {
2997                 $this->mRestrictionsLoaded = false;
2998                 $this->mTitleProtection = null;
2999         }
3000
3001         /**
3002          * Purge expired restrictions from the page_restrictions table
3003          */
3004         static function purgeExpiredRestrictions() {
3005                 if ( wfReadOnly() ) {
3006                         return;
3007                 }
3008
3009                 $method = __METHOD__;
3010                 $dbw = wfGetDB( DB_MASTER );
3011                 $dbw->onTransactionIdle( function () use ( $dbw, $method ) {
3012                         $dbw->delete(
3013                                 'page_restrictions',
3014                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3015                                 $method
3016                         );
3017                         $dbw->delete(
3018                                 'protected_titles',
3019                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
3020                                 $method
3021                         );
3022                 } );
3023         }
3024
3025         /**
3026          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3027          *
3028          * @return bool
3029          */
3030         public function hasSubpages() {
3031                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3032                         # Duh
3033                         return false;
3034                 }
3035
3036                 # We dynamically add a member variable for the purpose of this method
3037                 # alone to cache the result.  There's no point in having it hanging
3038                 # around uninitialized in every Title object; therefore we only add it
3039                 # if needed and don't declare it statically.
3040                 if ( $this->mHasSubpages === null ) {
3041                         $this->mHasSubpages = false;
3042                         $subpages = $this->getSubpages( 1 );
3043                         if ( $subpages instanceof TitleArray ) {
3044                                 $this->mHasSubpages = (bool)$subpages->count();
3045                         }
3046                 }
3047
3048                 return $this->mHasSubpages;
3049         }
3050
3051         /**
3052          * Get all subpages of this page.
3053          *
3054          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3055          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3056          *  doesn't allow subpages
3057          */
3058         public function getSubpages( $limit = -1 ) {
3059                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3060                         return array();
3061                 }
3062
3063                 $dbr = wfGetDB( DB_SLAVE );
3064                 $conds['page_namespace'] = $this->getNamespace();
3065                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3066                 $options = array();
3067                 if ( $limit > -1 ) {
3068                         $options['LIMIT'] = $limit;
3069                 }
3070                 $this->mSubpages = TitleArray::newFromResult(
3071                         $dbr->select( 'page',
3072                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
3073                                 $conds,
3074                                 __METHOD__,
3075                                 $options
3076                         )
3077                 );
3078                 return $this->mSubpages;
3079         }
3080
3081         /**
3082          * Is there a version of this page in the deletion archive?
3083          *
3084          * @return int The number of archived revisions
3085          */
3086         public function isDeleted() {
3087                 if ( $this->getNamespace() < 0 ) {
3088                         $n = 0;
3089                 } else {
3090                         $dbr = wfGetDB( DB_SLAVE );
3091
3092                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3093                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3094                                 __METHOD__
3095                         );
3096                         if ( $this->getNamespace() == NS_FILE ) {
3097                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3098                                         array( 'fa_name' => $this->getDBkey() ),
3099                                         __METHOD__
3100                                 );
3101                         }
3102                 }
3103                 return (int)$n;
3104         }
3105
3106         /**
3107          * Is there a version of this page in the deletion archive?
3108          *
3109          * @return bool
3110          */
3111         public function isDeletedQuick() {
3112                 if ( $this->getNamespace() < 0 ) {
3113                         return false;
3114                 }
3115                 $dbr = wfGetDB( DB_SLAVE );
3116                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3117                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3118                         __METHOD__
3119                 );
3120                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3121                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3122                                 array( 'fa_name' => $this->getDBkey() ),
3123                                 __METHOD__
3124                         );
3125                 }
3126                 return $deleted;
3127         }
3128
3129         /**
3130          * Get the article ID for this Title from the link cache,
3131          * adding it if necessary
3132          *
3133          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3134          *  for update
3135          * @return int The ID
3136          */
3137         public function getArticleID( $flags = 0 ) {
3138                 if ( $this->getNamespace() < 0 ) {
3139                         $this->mArticleID = 0;
3140                         return $this->mArticleID;
3141                 }
3142                 $linkCache = LinkCache::singleton();
3143                 if ( $flags & self::GAID_FOR_UPDATE ) {
3144                         $oldUpdate = $linkCache->forUpdate( true );
3145                         $linkCache->clearLink( $this );
3146                         $this->mArticleID = $linkCache->addLinkObj( $this );
3147                         $linkCache->forUpdate( $oldUpdate );
3148                 } else {
3149                         if ( -1 == $this->mArticleID ) {
3150                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3151                         }
3152                 }
3153                 return $this->mArticleID;
3154         }
3155
3156         /**
3157          * Is this an article that is a redirect page?
3158          * Uses link cache, adding it if necessary
3159          *
3160          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3161          * @return bool
3162          */
3163         public function isRedirect( $flags = 0 ) {
3164                 if ( !is_null( $this->mRedirect ) ) {
3165                         return $this->mRedirect;
3166                 }
3167                 # Calling getArticleID() loads the field from cache as needed
3168                 if ( !$this->getArticleID( $flags ) ) {
3169                         $this->mRedirect = false;
3170                         return $this->mRedirect;
3171                 }
3172
3173                 $linkCache = LinkCache::singleton();
3174                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3175                 if ( $cached === null ) {
3176                         # Trust LinkCache's state over our own
3177                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3178                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3179                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3180                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3181                         # LinkCache to refresh its data from the master.
3182                         $this->mRedirect = false;
3183                         return $this->mRedirect;
3184                 }
3185
3186                 $this->mRedirect = (bool)$cached;
3187
3188                 return $this->mRedirect;
3189         }
3190
3191         /**
3192          * What is the length of this page?
3193          * Uses link cache, adding it if necessary
3194          *
3195          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3196          * @return int
3197          */
3198         public function getLength( $flags = 0 ) {
3199                 if ( $this->mLength != -1 ) {
3200                         return $this->mLength;
3201                 }
3202                 # Calling getArticleID() loads the field from cache as needed
3203                 if ( !$this->getArticleID( $flags ) ) {
3204                         $this->mLength = 0;
3205                         return $this->mLength;
3206                 }
3207                 $linkCache = LinkCache::singleton();
3208                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3209                 if ( $cached === null ) {
3210                         # Trust LinkCache's state over our own, as for isRedirect()
3211                         $this->mLength = 0;
3212                         return $this->mLength;
3213                 }
3214
3215                 $this->mLength = intval( $cached );
3216
3217                 return $this->mLength;
3218         }
3219
3220         /**
3221          * What is the page_latest field for this page?
3222          *
3223          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3224          * @return int Int or 0 if the page doesn't exist
3225          */
3226         public function getLatestRevID( $flags = 0 ) {
3227                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3228                         return intval( $this->mLatestID );
3229                 }
3230                 # Calling getArticleID() loads the field from cache as needed
3231                 if ( !$this->getArticleID( $flags ) ) {
3232                         $this->mLatestID = 0;
3233                         return $this->mLatestID;
3234                 }
3235                 $linkCache = LinkCache::singleton();
3236                 $linkCache->addLinkObj( $this );
3237                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3238                 if ( $cached === null ) {
3239                         # Trust LinkCache's state over our own, as for isRedirect()
3240                         $this->mLatestID = 0;
3241                         return $this->mLatestID;
3242                 }
3243
3244                 $this->mLatestID = intval( $cached );
3245
3246                 return $this->mLatestID;
3247         }
3248
3249         /**
3250          * This clears some fields in this object, and clears any associated
3251          * keys in the "bad links" section of the link cache.
3252          *
3253          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3254          * loading of the new page_id. It's also called from
3255          * WikiPage::doDeleteArticleReal()
3256          *
3257          * @param int $newid The new Article ID
3258          */
3259         public function resetArticleID( $newid ) {
3260                 $linkCache = LinkCache::singleton();
3261                 $linkCache->clearLink( $this );
3262
3263                 if ( $newid === false ) {
3264                         $this->mArticleID = -1;
3265                 } else {
3266                         $this->mArticleID = intval( $newid );
3267                 }
3268                 $this->mRestrictionsLoaded = false;
3269                 $this->mRestrictions = array();
3270                 $this->mRedirect = null;
3271                 $this->mLength = -1;
3272                 $this->mLatestID = false;
3273                 $this->mContentModel = false;
3274                 $this->mEstimateRevisions = null;
3275                 $this->mPageLanguage = false;
3276                 $this->mDbPageLanguage = null;
3277                 $this->mIsBigDeletion = null;
3278         }
3279
3280         /**
3281          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3282          *
3283          * @param string $text Containing title to capitalize
3284          * @param int $ns Namespace index, defaults to NS_MAIN
3285          * @return string Containing capitalized title
3286          */
3287         public static function capitalize( $text, $ns = NS_MAIN ) {
3288                 global $wgContLang;
3289
3290                 if ( MWNamespace::isCapitalized( $ns ) ) {
3291                         return $wgContLang->ucfirst( $text );
3292                 } else {
3293                         return $text;
3294                 }
3295         }
3296
3297         /**
3298          * Secure and split - main initialisation function for this object
3299          *
3300          * Assumes that mDbkeyform has been set, and is urldecoded
3301          * and uses underscores, but not otherwise munged.  This function
3302          * removes illegal characters, splits off the interwiki and
3303          * namespace prefixes, sets the other forms, and canonicalizes
3304          * everything.
3305          *
3306          * @return bool True on success
3307          */
3308         private function secureAndSplit() {
3309                 # Initialisation
3310                 $this->mInterwiki = '';
3311                 $this->mFragment = '';
3312                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3313
3314                 $dbkey = $this->mDbkeyform;
3315
3316                 try {
3317                         // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3318                         //        the parsing code with Title, while avoiding massive refactoring.
3319                         // @todo: get rid of secureAndSplit, refactor parsing code.
3320                         $parser = self::getTitleParser();
3321                         $parts = $parser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3322                 } catch ( MalformedTitleException $ex ) {
3323                         return false;
3324                 }
3325
3326                 # Fill fields
3327                 $this->setFragment( '#' . $parts['fragment'] );
3328                 $this->mInterwiki = $parts['interwiki'];
3329                 $this->mLocalInterwiki = $parts['local_interwiki'];
3330                 $this->mNamespace = $parts['namespace'];
3331                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3332
3333                 $this->mDbkeyform = $parts['dbkey'];
3334                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3335                 $this->mTextform = str_replace( '_', ' ', $this->mDbkeyform );
3336
3337                 # We already know that some pages won't be in the database!
3338                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3339                         $this->mArticleID = 0;
3340                 }
3341
3342                 return true;
3343         }
3344
3345         /**
3346          * Get an array of Title objects linking to this Title
3347          * Also stores the IDs in the link cache.
3348          *
3349          * WARNING: do not use this function on arbitrary user-supplied titles!
3350          * On heavily-used templates it will max out the memory.
3351          *
3352          * @param array $options May be FOR UPDATE
3353          * @param string $table Table name
3354          * @param string $prefix Fields prefix
3355          * @return Title[] Array of Title objects linking here
3356          */
3357         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3358                 if ( count( $options ) > 0 ) {
3359                         $db = wfGetDB( DB_MASTER );
3360                 } else {
3361                         $db = wfGetDB( DB_SLAVE );
3362                 }
3363
3364                 $res = $db->select(
3365                         array( 'page', $table ),
3366                         self::getSelectFields(),
3367                         array(
3368                                 "{$prefix}_from=page_id",
3369                                 "{$prefix}_namespace" => $this->getNamespace(),
3370                                 "{$prefix}_title" => $this->getDBkey() ),
3371                         __METHOD__,
3372                         $options
3373                 );
3374
3375                 $retVal = array();
3376                 if ( $res->numRows() ) {
3377                         $linkCache = LinkCache::singleton();
3378                         foreach ( $res as $row ) {
3379                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3380                                 if ( $titleObj ) {
3381                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3382                                         $retVal[] = $titleObj;
3383                                 }
3384                         }
3385                 }
3386                 return $retVal;
3387         }
3388
3389         /**
3390          * Get an array of Title objects using this Title as a template
3391          * Also stores the IDs in the link cache.
3392          *
3393          * WARNING: do not use this function on arbitrary user-supplied titles!
3394          * On heavily-used templates it will max out the memory.
3395          *
3396          * @param array $options May be FOR UPDATE
3397          * @return Title[] Array of Title the Title objects linking here
3398          */
3399         public function getTemplateLinksTo( $options = array() ) {
3400                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3401         }
3402
3403         /**
3404          * Get an array of Title objects linked from this Title
3405          * Also stores the IDs in the link cache.
3406          *
3407          * WARNING: do not use this function on arbitrary user-supplied titles!
3408          * On heavily-used templates it will max out the memory.
3409          *
3410          * @param array $options May be FOR UPDATE
3411          * @param string $table Table name
3412          * @param string $prefix Fields prefix
3413          * @return array Array of Title objects linking here
3414          */
3415         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3416                 global $wgContentHandlerUseDB;
3417
3418                 $id = $this->getArticleID();
3419
3420                 # If the page doesn't exist; there can't be any link from this page
3421                 if ( !$id ) {
3422                         return array();
3423                 }
3424
3425                 if ( count( $options ) > 0 ) {
3426                         $db = wfGetDB( DB_MASTER );
3427                 } else {
3428                         $db = wfGetDB( DB_SLAVE );
3429                 }
3430
3431                 $namespaceFiled = "{$prefix}_namespace";
3432                 $titleField = "{$prefix}_title";
3433
3434                 $fields = array(
3435                         $namespaceFiled,
3436                         $titleField,
3437                         'page_id',
3438                         'page_len',
3439                         'page_is_redirect',
3440                         'page_latest'
3441                 );
3442
3443                 if ( $wgContentHandlerUseDB ) {
3444                         $fields[] = 'page_content_model';
3445                 }
3446
3447                 $res = $db->select(
3448                         array( $table, 'page' ),
3449                         $fields,
3450                         array( "{$prefix}_from" => $id ),
3451                         __METHOD__,
3452                         $options,
3453                         array( 'page' => array(
3454                                 'LEFT JOIN',
3455                                 array( "page_namespace=$namespaceFiled", "page_title=$titleField" )
3456                         ) )
3457                 );
3458
3459                 $retVal = array();
3460                 if ( $res->numRows() ) {
3461                         $linkCache = LinkCache::singleton();
3462                         foreach ( $res as $row ) {
3463                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3464                                 if ( $titleObj ) {
3465                                         if ( $row->page_id ) {
3466                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3467                                         } else {
3468                                                 $linkCache->addBadLinkObj( $titleObj );
3469                                         }
3470                                         $retVal[] = $titleObj;
3471                                 }
3472                         }
3473                 }
3474                 return $retVal;
3475         }
3476
3477         /**
3478          * Get an array of Title objects used on this Title as a template
3479          * Also stores the IDs in the link cache.
3480          *
3481          * WARNING: do not use this function on arbitrary user-supplied titles!
3482          * On heavily-used templates it will max out the memory.
3483          *
3484          * @param array $options May be FOR UPDATE
3485          * @return Title[] Array of Title the Title objects used here
3486          */
3487         public function getTemplateLinksFrom( $options = array() ) {
3488                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3489         }
3490
3491         /**
3492          * Get an array of Title objects referring to non-existent articles linked
3493          * from this page.
3494          *
3495          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3496          *   should use redirect table in this case).
3497          * @return Title[] Array of Title the Title objects
3498          */
3499         public function getBrokenLinksFrom() {
3500                 if ( $this->getArticleID() == 0 ) {
3501                         # All links from article ID 0 are false positives
3502                         return array();
3503                 }
3504
3505                 $dbr = wfGetDB( DB_SLAVE );
3506                 $res = $dbr->select(
3507                         array( 'page', 'pagelinks' ),
3508                         array( 'pl_namespace', 'pl_title' ),
3509                         array(
3510                                 'pl_from' => $this->getArticleID(),
3511                                 'page_namespace IS NULL'
3512                         ),
3513                         __METHOD__, array(),
3514                         array(
3515                                 'page' => array(
3516                                         'LEFT JOIN',
3517                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3518                                 )
3519                         )
3520                 );
3521
3522                 $retVal = array();
3523                 foreach ( $res as $row ) {
3524                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3525                 }
3526                 return $retVal;
3527         }
3528
3529         /**
3530          * Get a list of URLs to purge from the Squid cache when this
3531          * page changes
3532          *
3533          * @return string[] Array of String the URLs
3534          */
3535         public function getSquidURLs() {
3536                 $urls = array(
3537                         $this->getInternalURL(),
3538                         $this->getInternalURL( 'action=history' )
3539                 );
3540
3541                 $pageLang = $this->getPageLanguage();
3542                 if ( $pageLang->hasVariants() ) {
3543                         $variants = $pageLang->getVariants();
3544                         foreach ( $variants as $vCode ) {
3545                                 $urls[] = $this->getInternalURL( '', $vCode );
3546                         }
3547                 }
3548
3549                 // If we are looking at a css/js user subpage, purge the action=raw.
3550                 if ( $this->isJsSubpage() ) {
3551                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3552                 } elseif ( $this->isCssSubpage() ) {
3553                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3554                 }
3555
3556                 wfRunHooks( 'TitleSquidURLs', array( $this, &$urls ) );
3557                 return $urls;
3558         }
3559
3560         /**
3561          * Purge all applicable Squid URLs
3562          */
3563         public function purgeSquid() {
3564                 global $wgUseSquid;
3565                 if ( $wgUseSquid ) {
3566                         $urls = $this->getSquidURLs();
3567                         $u = new SquidUpdate( $urls );
3568                         $u->doUpdate();
3569                 }
3570         }
3571
3572         /**
3573          * Move this page without authentication
3574          *
3575          * @param Title $nt The new page Title
3576          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3577          */
3578         public function moveNoAuth( &$nt ) {
3579                 return $this->moveTo( $nt, false );
3580         }
3581
3582         /**
3583          * Check whether a given move operation would be valid.
3584          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3585          *
3586          * @param Title $nt The new title
3587          * @param bool $auth Indicates whether $wgUser's permissions
3588          *  should be checked
3589          * @param string $reason Is the log summary of the move, used for spam checking
3590          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3591          */
3592         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3593                 global $wgUser, $wgContentHandlerUseDB;
3594
3595                 $errors = array();
3596                 if ( !$nt ) {
3597                         // Normally we'd add this to $errors, but we'll get
3598                         // lots of syntax errors if $nt is not an object
3599                         return array( array( 'badtitletext' ) );
3600                 }
3601                 if ( $this->equals( $nt ) ) {
3602                         $errors[] = array( 'selfmove' );
3603                 }
3604                 if ( !$this->isMovable() ) {
3605                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3606                 }
3607                 if ( $nt->isExternal() ) {
3608                         $errors[] = array( 'immobile-target-namespace-iw' );
3609                 }
3610                 if ( !$nt->isMovable() ) {
3611                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3612                 }
3613
3614                 $oldid = $this->getArticleID();
3615                 $newid = $nt->getArticleID();
3616
3617                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3618                         $errors[] = array( 'articleexists' );
3619                 }
3620                 if (
3621                         ( $this->getDBkey() == '' ) ||
3622                         ( !$oldid ) ||
3623                         ( $nt->getDBkey() == '' )
3624                 ) {
3625                         $errors[] = array( 'badarticleerror' );
3626                 }
3627
3628                 // Content model checks
3629                 if ( !$wgContentHandlerUseDB &&
3630                                 $this->getContentModel() !== $nt->getContentModel() ) {
3631                         // can't move a page if that would change the page's content model
3632                         $errors[] = array(
3633                                 'bad-target-model',
3634                                 ContentHandler::getLocalizedName( $this->getContentModel() ),
3635                                 ContentHandler::getLocalizedName( $nt->getContentModel() )
3636                         );
3637                 }
3638
3639                 // Image-specific checks
3640                 if ( $this->getNamespace() == NS_FILE ) {
3641                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3642                 }
3643
3644                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3645                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3646                 }
3647
3648                 if ( $auth ) {
3649                         $errors = wfMergeErrorArrays( $errors,
3650                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3651                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3652                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3653                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3654                 }
3655
3656                 $match = EditPage::matchSummarySpamRegex( $reason );
3657                 if ( $match !== false ) {
3658                         // This is kind of lame, won't display nice
3659                         $errors[] = array( 'spamprotectiontext' );
3660                 }
3661
3662                 $err = null;
3663                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3664                         $errors[] = array( 'hookaborted', $err );
3665                 }
3666
3667                 # The move is allowed only if (1) the target doesn't exist, or
3668                 # (2) the target is a redirect to the source, and has no history
3669                 # (so we can undo bad moves right after they're done).
3670
3671                 if ( 0 != $newid ) { # Target exists; check for validity
3672                         if ( !$this->isValidMoveTarget( $nt ) ) {
3673                                 $errors[] = array( 'articleexists' );
3674                         }
3675                 } else {
3676                         $tp = $nt->getTitleProtection();
3677                         $right = $tp['pt_create_perm'];
3678                         if ( $right == 'sysop' ) {
3679                                 $right = 'editprotected'; // B/C
3680                         }
3681                         if ( $right == 'autoconfirmed' ) {
3682                                 $right = 'editsemiprotected'; // B/C
3683                         }
3684                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3685                                 $errors[] = array( 'cantmove-titleprotected' );
3686                         }
3687                 }
3688                 if ( empty( $errors ) ) {
3689                         return true;
3690                 }
3691                 return $errors;
3692         }
3693
3694         /**
3695          * Check if the requested move target is a valid file move target
3696          * @param Title $nt Target title
3697          * @return array List of errors
3698          */
3699         protected function validateFileMoveOperation( $nt ) {
3700                 global $wgUser;
3701
3702                 $errors = array();
3703
3704                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3705
3706                 $file = wfLocalFile( $this );
3707                 if ( $file->exists() ) {
3708                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3709                                 $errors[] = array( 'imageinvalidfilename' );
3710                         }
3711                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3712                                 $errors[] = array( 'imagetypemismatch' );
3713                         }
3714                 }
3715
3716                 if ( $nt->getNamespace() != NS_FILE ) {
3717                         $errors[] = array( 'imagenocrossnamespace' );
3718                         // From here we want to do checks on a file object, so if we can't
3719                         // create one, we must return.
3720                         return $errors;
3721                 }
3722
3723                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3724
3725                 $destFile = wfLocalFile( $nt );
3726                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3727                         $errors[] = array( 'file-exists-sharedrepo' );
3728                 }
3729
3730                 return $errors;
3731         }
3732
3733         /**
3734          * Move a title to a new location
3735          *
3736          * @param Title $nt The new title
3737          * @param bool $auth Indicates whether $wgUser's permissions
3738          *  should be checked
3739          * @param string $reason The reason for the move
3740          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3741          *  Ignored if the user doesn't have the suppressredirect right.
3742          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3743          */
3744         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3745                 global $wgUser;
3746                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3747                 if ( is_array( $err ) ) {
3748                         // Auto-block user's IP if the account was "hard" blocked
3749                         $wgUser->spreadAnyEditBlock();
3750                         return $err;
3751                 }
3752                 // Check suppressredirect permission
3753                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3754                         $createRedirect = true;
3755                 }
3756
3757                 wfRunHooks( 'TitleMove', array( $this, $nt, $wgUser ) );
3758
3759                 // If it is a file, move it first.
3760                 // It is done before all other moving stuff is done because it's hard to revert.
3761                 $dbw = wfGetDB( DB_MASTER );
3762                 if ( $this->getNamespace() == NS_FILE ) {
3763                         $file = wfLocalFile( $this );
3764                         if ( $file->exists() ) {
3765                                 $status = $file->move( $nt );
3766                                 if ( !$status->isOk() ) {
3767                                         return $status->getErrorsArray();
3768                                 }
3769                         }
3770                         // Clear RepoGroup process cache
3771                         RepoGroup::singleton()->clearCache( $this );
3772                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3773                 }
3774
3775                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3776                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3777                 $protected = $this->isProtected();
3778
3779                 // Do the actual move
3780                 $this->moveToInternal( $nt, $reason, $createRedirect );
3781
3782                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3783                 // cl_timestamp, which may disturb time-based lists on some sites.
3784                 $prefixes = $dbw->select(
3785                         'categorylinks',
3786                         array( 'cl_sortkey_prefix', 'cl_to' ),
3787                         array( 'cl_from' => $pageid ),
3788                         __METHOD__
3789                 );
3790                 foreach ( $prefixes as $prefixRow ) {
3791                         $prefix = $prefixRow->cl_sortkey_prefix;
3792                         $catTo = $prefixRow->cl_to;
3793                         $dbw->update( 'categorylinks',
3794                                 array(
3795                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3796                                                 $nt->getCategorySortkey( $prefix ) ),
3797                                         'cl_timestamp=cl_timestamp' ),
3798                                 array(
3799                                         'cl_from' => $pageid,
3800                                         'cl_to' => $catTo ),
3801                                 __METHOD__
3802                         );
3803                 }
3804
3805                 $redirid = $this->getArticleID();
3806
3807                 if ( $protected ) {
3808                         # Protect the redirect title as the title used to be...
3809                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3810                                 array(
3811                                         'pr_page' => $redirid,
3812                                         'pr_type' => 'pr_type',
3813                                         'pr_level' => 'pr_level',
3814                                         'pr_cascade' => 'pr_cascade',
3815                                         'pr_user' => 'pr_user',
3816                                         'pr_expiry' => 'pr_expiry'
3817                                 ),
3818                                 array( 'pr_page' => $pageid ),
3819                                 __METHOD__,
3820                                 array( 'IGNORE' )
3821                         );
3822                         # Update the protection log
3823                         $log = new LogPage( 'protect' );
3824                         $comment = wfMessage(
3825                                 'prot_1movedto2',
3826                                 $this->getPrefixedText(),
3827                                 $nt->getPrefixedText()
3828                         )->inContentLanguage()->text();
3829                         if ( $reason ) {
3830                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3831                         }
3832                         // @todo FIXME: $params?
3833                         $logId = $log->addEntry(
3834                                 'move_prot',
3835                                 $nt,
3836                                 $comment,
3837                                 array( $this->getPrefixedText() ),
3838                                 $wgUser
3839                         );
3840
3841                         // reread inserted pr_ids for log relation
3842                         $insertedPrIds = $dbw->select(
3843                                 'page_restrictions',
3844                                 'pr_id',
3845                                 array( 'pr_page' => $redirid ),
3846                                 __METHOD__
3847                         );
3848                         $logRelationsValues = array();
3849                         foreach ( $insertedPrIds as $prid ) {
3850                                 $logRelationsValues[] = $prid->pr_id;
3851                         }
3852                         $log->addRelations( 'pr_id', $logRelationsValues, $logId );
3853                 }
3854
3855                 // Update *_from_namespace fields as needed
3856                 if ( $this->getNamespace() != $nt->getNamespace() ) {
3857                         $dbw->update( 'pagelinks',
3858                                 array( 'pl_from_namespace' => $nt->getNamespace() ),
3859                                 array( 'pl_from' => $pageid ),
3860                                 __METHOD__
3861                         );
3862                         $dbw->update( 'templatelinks',
3863                                 array( 'tl_from_namespace' => $nt->getNamespace() ),
3864                                 array( 'tl_from' => $pageid ),
3865                                 __METHOD__
3866                         );
3867                         $dbw->update( 'imagelinks',
3868                                 array( 'il_from_namespace' => $nt->getNamespace() ),
3869                                 array( 'il_from' => $pageid ),
3870                                 __METHOD__
3871                         );
3872                 }
3873
3874                 # Update watchlists
3875                 $oldtitle = $this->getDBkey();
3876                 $newtitle = $nt->getDBkey();
3877                 $oldsnamespace = MWNamespace::getSubject( $this->getNamespace() );
3878                 $newsnamespace = MWNamespace::getSubject( $nt->getNamespace() );
3879                 if ( $oldsnamespace != $newsnamespace || $oldtitle != $newtitle ) {
3880                         WatchedItem::duplicateEntries( $this, $nt );
3881                 }
3882
3883                 $dbw->commit( __METHOD__ );
3884
3885                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid, $reason ) );
3886                 return true;
3887         }
3888
3889         /**
3890          * Move page to a title which is either a redirect to the
3891          * source page or nonexistent
3892          *
3893          * @param Title $nt The page to move to, which should be a redirect or nonexistent
3894          * @param string $reason The reason for the move
3895          * @param bool $createRedirect Whether to leave a redirect at the old title. Does not check
3896          *   if the user has the suppressredirect right
3897          * @throws MWException
3898          */
3899         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3900                 global $wgUser, $wgContLang;
3901
3902                 if ( $nt->exists() ) {
3903                         $moveOverRedirect = true;
3904                         $logType = 'move_redir';
3905                 } else {
3906                         $moveOverRedirect = false;
3907                         $logType = 'move';
3908                 }
3909
3910                 if ( $createRedirect ) {
3911                         if ( $this->getNamespace() == NS_CATEGORY
3912                                 && !wfMessage( 'category-move-redirect-override' )->inContentLanguage()->isDisabled()
3913                         ) {
3914                                 $redirectContent = new WikitextContent(
3915                                         wfMessage( 'category-move-redirect-override' )
3916                                                 ->params( $nt->getPrefixedText() )->inContentLanguage()->plain() );
3917                         } else {
3918                                 $contentHandler = ContentHandler::getForTitle( $this );
3919                                 $redirectContent = $contentHandler->makeRedirectContent( $nt,
3920                                         wfMessage( 'move-redirect-text' )->inContentLanguage()->plain() );
3921                         }
3922
3923                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3924                 } else {
3925                         $redirectContent = null;
3926                 }
3927
3928                 $logEntry = new ManualLogEntry( 'move', $logType );
3929                 $logEntry->setPerformer( $wgUser );
3930                 $logEntry->setTarget( $this );
3931                 $logEntry->setComment( $reason );
3932                 $logEntry->setParameters( array(
3933                         '4::target' => $nt->getPrefixedText(),
3934                         '5::noredir' => $redirectContent ? '0': '1',
3935                 ) );
3936
3937                 $formatter = LogFormatter::newFromEntry( $logEntry );
3938                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3939                 $comment = $formatter->getPlainActionText();
3940                 if ( $reason ) {
3941                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3942                 }
3943                 # Truncate for whole multibyte characters.
3944                 $comment = $wgContLang->truncate( $comment, 255 );
3945
3946                 $oldid = $this->getArticleID();
3947
3948                 $dbw = wfGetDB( DB_MASTER );
3949
3950                 $newpage = WikiPage::factory( $nt );
3951
3952                 if ( $moveOverRedirect ) {
3953                         $newid = $nt->getArticleID();
3954                         $newcontent = $newpage->getContent();
3955
3956                         # Delete the old redirect. We don't save it to history since
3957                         # by definition if we've got here it's rather uninteresting.
3958                         # We have to remove it so that the next step doesn't trigger
3959                         # a conflict on the unique namespace+title index...
3960                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3961
3962                         $newpage->doDeleteUpdates( $newid, $newcontent );
3963                 }
3964
3965                 # Save a null revision in the page's history notifying of the move
3966                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true, $wgUser );
3967                 if ( !is_object( $nullRevision ) ) {
3968                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3969                 }
3970
3971                 $nullRevision->insertOn( $dbw );
3972
3973                 # Change the name of the target page:
3974                 $dbw->update( 'page',
3975                         /* SET */ array(
3976                                 'page_namespace' => $nt->getNamespace(),
3977                                 'page_title' => $nt->getDBkey(),
3978                         ),
3979                         /* WHERE */ array( 'page_id' => $oldid ),
3980                         __METHOD__
3981                 );
3982
3983                 // clean up the old title before reset article id - bug 45348
3984                 if ( !$redirectContent ) {
3985                         WikiPage::onArticleDelete( $this );
3986                 }
3987
3988                 $this->resetArticleID( 0 ); // 0 == non existing
3989                 $nt->resetArticleID( $oldid );
3990                 $newpage->loadPageData( WikiPage::READ_LOCKING ); // bug 46397
3991
3992                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3993
3994                 wfRunHooks( 'NewRevisionFromEditComplete',
3995                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3996
3997                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3998
3999                 if ( !$moveOverRedirect ) {
4000                         WikiPage::onArticleCreate( $nt );
4001                 }
4002
4003                 # Recreate the redirect, this time in the other direction.
4004                 if ( $redirectContent ) {
4005                         $redirectArticle = WikiPage::factory( $this );
4006                         $redirectArticle->loadFromRow( false, WikiPage::READ_LOCKING ); // bug 46397
4007                         $newid = $redirectArticle->insertOn( $dbw );
4008                         if ( $newid ) { // sanity
4009                                 $this->resetArticleID( $newid );
4010                                 $redirectRevision = new Revision( array(
4011                                         'title' => $this, // for determining the default content model
4012                                         'page' => $newid,
4013                                         'user_text' => $wgUser->getName(),
4014                                         'user' => $wgUser->getId(),
4015                                         'comment' => $comment,
4016                                         'content' => $redirectContent ) );
4017                                 $redirectRevision->insertOn( $dbw );
4018                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
4019
4020                                 wfRunHooks( 'NewRevisionFromEditComplete',
4021                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
4022
4023                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
4024                         }
4025                 }
4026
4027                 # Log the move
4028                 $logid = $logEntry->insert();
4029                 $logEntry->publish( $logid );
4030         }
4031
4032         /**
4033          * Move this page's subpages to be subpages of $nt
4034          *
4035          * @param Title $nt Move target
4036          * @param bool $auth Whether $wgUser's permissions should be checked
4037          * @param string $reason The reason for the move
4038          * @param bool $createRedirect Whether to create redirects from the old subpages to
4039          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
4040          * @return array Array with old page titles as keys, and strings (new page titles) or
4041          *     arrays (errors) as values, or an error array with numeric indices if no pages
4042          *     were moved
4043          */
4044         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
4045                 global $wgMaximumMovedPages;
4046                 // Check permissions
4047                 if ( !$this->userCan( 'move-subpages' ) ) {
4048                         return array( 'cant-move-subpages' );
4049                 }
4050                 // Do the source and target namespaces support subpages?
4051                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4052                         return array( 'namespace-nosubpages',
4053                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
4054                 }
4055                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
4056                         return array( 'namespace-nosubpages',
4057                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
4058                 }
4059
4060                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
4061                 $retval = array();
4062                 $count = 0;
4063                 foreach ( $subpages as $oldSubpage ) {
4064                         $count++;
4065                         if ( $count > $wgMaximumMovedPages ) {
4066                                 $retval[$oldSubpage->getPrefixedText()] =
4067                                                 array( 'movepage-max-pages',
4068                                                         $wgMaximumMovedPages );
4069                                 break;
4070                         }
4071
4072                         // We don't know whether this function was called before
4073                         // or after moving the root page, so check both
4074                         // $this and $nt
4075                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
4076                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
4077                         ) {
4078                                 // When moving a page to a subpage of itself,
4079                                 // don't move it twice
4080                                 continue;
4081                         }
4082                         $newPageName = preg_replace(
4083                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
4084                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
4085                                         $oldSubpage->getDBkey() );
4086                         if ( $oldSubpage->isTalkPage() ) {
4087                                 $newNs = $nt->getTalkPage()->getNamespace();
4088                         } else {
4089                                 $newNs = $nt->getSubjectPage()->getNamespace();
4090                         }
4091                         # Bug 14385: we need makeTitleSafe because the new page names may
4092                         # be longer than 255 characters.
4093                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
4094
4095                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
4096                         if ( $success === true ) {
4097                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
4098                         } else {
4099                                 $retval[$oldSubpage->getPrefixedText()] = $success;
4100                         }
4101                 }
4102                 return $retval;
4103         }
4104
4105         /**
4106          * Checks if this page is just a one-rev redirect.
4107          * Adds lock, so don't use just for light purposes.
4108          *
4109          * @return bool
4110          */
4111         public function isSingleRevRedirect() {
4112                 global $wgContentHandlerUseDB;
4113
4114                 $dbw = wfGetDB( DB_MASTER );
4115
4116                 # Is it a redirect?
4117                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
4118                 if ( $wgContentHandlerUseDB ) {
4119                         $fields[] = 'page_content_model';
4120                 }
4121
4122                 $row = $dbw->selectRow( 'page',
4123                         $fields,
4124                         $this->pageCond(),
4125                         __METHOD__,
4126                         array( 'FOR UPDATE' )
4127                 );
4128                 # Cache some fields we may want
4129                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
4130                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
4131                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
4132                 $this->mContentModel = $row && isset( $row->page_content_model )
4133                         ? strval( $row->page_content_model )
4134                         : false;
4135
4136                 if ( !$this->mRedirect ) {
4137                         return false;
4138                 }
4139                 # Does the article have a history?
4140                 $row = $dbw->selectField( array( 'page', 'revision' ),
4141                         'rev_id',
4142                         array( 'page_namespace' => $this->getNamespace(),
4143                                 'page_title' => $this->getDBkey(),
4144                                 'page_id=rev_page',
4145                                 'page_latest != rev_id'
4146                         ),
4147                         __METHOD__,
4148                         array( 'FOR UPDATE' )
4149                 );
4150                 # Return true if there was no history
4151                 return ( $row === false );
4152         }
4153
4154         /**
4155          * Checks if $this can be moved to a given Title
4156          * - Selects for update, so don't call it unless you mean business
4157          *
4158          * @param Title $nt The new title to check
4159          * @return bool
4160          */
4161         public function isValidMoveTarget( $nt ) {
4162                 # Is it an existing file?
4163                 if ( $nt->getNamespace() == NS_FILE ) {
4164                         $file = wfLocalFile( $nt );
4165                         if ( $file->exists() ) {
4166                                 wfDebug( __METHOD__ . ": file exists\n" );
4167                                 return false;
4168                         }
4169                 }
4170                 # Is it a redirect with no history?
4171                 if ( !$nt->isSingleRevRedirect() ) {
4172                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
4173                         return false;
4174                 }
4175                 # Get the article text
4176                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
4177                 if ( !is_object( $rev ) ) {
4178                         return false;
4179                 }
4180                 $content = $rev->getContent();
4181                 # Does the redirect point to the source?
4182                 # Or is it a broken self-redirect, usually caused by namespace collisions?
4183                 $redirTitle = $content ? $content->getRedirectTarget() : null;
4184
4185                 if ( $redirTitle ) {
4186                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
4187                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
4188                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
4189                                 return false;
4190                         } else {
4191                                 return true;
4192                         }
4193                 } else {
4194                         # Fail safe (not a redirect after all. strange.)
4195                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
4196                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
4197                         return false;
4198                 }
4199         }
4200
4201         /**
4202          * Get categories to which this Title belongs and return an array of
4203          * categories' names.
4204          *
4205          * @return array Array of parents in the form:
4206          *        $parent => $currentarticle
4207          */
4208         public function getParentCategories() {
4209                 global $wgContLang;
4210
4211                 $data = array();
4212
4213                 $titleKey = $this->getArticleID();
4214
4215                 if ( $titleKey === 0 ) {
4216                         return $data;
4217                 }
4218
4219                 $dbr = wfGetDB( DB_SLAVE );
4220
4221                 $res = $dbr->select(
4222                         'categorylinks',
4223                         'cl_to',
4224                         array( 'cl_from' => $titleKey ),
4225                         __METHOD__
4226                 );
4227
4228                 if ( $res->numRows() > 0 ) {
4229                         foreach ( $res as $row ) {
4230                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
4231                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4232                         }
4233                 }
4234                 return $data;
4235         }
4236
4237         /**
4238          * Get a tree of parent categories
4239          *
4240          * @param array $children Array with the children in the keys, to check for circular refs
4241          * @return array Tree of parent categories
4242          */
4243         public function getParentCategoryTree( $children = array() ) {
4244                 $stack = array();
4245                 $parents = $this->getParentCategories();
4246
4247                 if ( $parents ) {
4248                         foreach ( $parents as $parent => $current ) {
4249                                 if ( array_key_exists( $parent, $children ) ) {
4250                                         # Circular reference
4251                                         $stack[$parent] = array();
4252                                 } else {
4253                                         $nt = Title::newFromText( $parent );
4254                                         if ( $nt ) {
4255                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4256                                         }
4257                                 }
4258                         }
4259                 }
4260
4261                 return $stack;
4262         }
4263
4264         /**
4265          * Get an associative array for selecting this title from
4266          * the "page" table
4267          *
4268          * @return array Array suitable for the $where parameter of DB::select()
4269          */
4270         public function pageCond() {
4271                 if ( $this->mArticleID > 0 ) {
4272                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4273                         return array( 'page_id' => $this->mArticleID );
4274                 } else {
4275                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4276                 }
4277         }
4278
4279         /**
4280          * Get the revision ID of the previous revision
4281          *
4282          * @param int $revId Revision ID. Get the revision that was before this one.
4283          * @param int $flags Title::GAID_FOR_UPDATE
4284          * @return int|bool Old revision ID, or false if none exists
4285          */
4286         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4287                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4288                 $revId = $db->selectField( 'revision', 'rev_id',
4289                         array(
4290                                 'rev_page' => $this->getArticleID( $flags ),
4291                                 'rev_id < ' . intval( $revId )
4292                         ),
4293                         __METHOD__,
4294                         array( 'ORDER BY' => 'rev_id DESC' )
4295                 );
4296
4297                 if ( $revId === false ) {
4298                         return false;
4299                 } else {
4300                         return intval( $revId );
4301                 }
4302         }
4303
4304         /**
4305          * Get the revision ID of the next revision
4306          *
4307          * @param int $revId Revision ID. Get the revision that was after this one.
4308          * @param int $flags Title::GAID_FOR_UPDATE
4309          * @return int|bool Next revision ID, or false if none exists
4310          */
4311         public function getNextRevisionID( $revId, $flags = 0 ) {
4312                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4313                 $revId = $db->selectField( 'revision', 'rev_id',
4314                         array(
4315                                 'rev_page' => $this->getArticleID( $flags ),
4316                                 'rev_id > ' . intval( $revId )
4317                         ),
4318                         __METHOD__,
4319                         array( 'ORDER BY' => 'rev_id' )
4320                 );
4321
4322                 if ( $revId === false ) {
4323                         return false;
4324                 } else {
4325                         return intval( $revId );
4326                 }
4327         }
4328
4329         /**
4330          * Get the first revision of the page
4331          *
4332          * @param int $flags Title::GAID_FOR_UPDATE
4333          * @return Revision|null If page doesn't exist
4334          */
4335         public function getFirstRevision( $flags = 0 ) {
4336                 $pageId = $this->getArticleID( $flags );
4337                 if ( $pageId ) {
4338                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4339                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4340                                 array( 'rev_page' => $pageId ),
4341                                 __METHOD__,
4342                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4343                         );
4344                         if ( $row ) {
4345                                 return new Revision( $row );
4346                         }
4347                 }
4348                 return null;
4349         }
4350
4351         /**
4352          * Get the oldest revision timestamp of this page
4353          *
4354          * @param int $flags Title::GAID_FOR_UPDATE
4355          * @return string MW timestamp
4356          */
4357         public function getEarliestRevTime( $flags = 0 ) {
4358                 $rev = $this->getFirstRevision( $flags );
4359                 return $rev ? $rev->getTimestamp() : null;
4360         }
4361
4362         /**
4363          * Check if this is a new page
4364          *
4365          * @return bool
4366          */
4367         public function isNewPage() {
4368                 $dbr = wfGetDB( DB_SLAVE );
4369                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4370         }
4371
4372         /**
4373          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4374          *
4375          * @return bool
4376          */
4377         public function isBigDeletion() {
4378                 global $wgDeleteRevisionsLimit;
4379
4380                 if ( !$wgDeleteRevisionsLimit ) {
4381                         return false;
4382                 }
4383
4384                 if ( $this->mIsBigDeletion === null ) {
4385                         $dbr = wfGetDB( DB_SLAVE );
4386
4387                         $innerQuery = $dbr->selectSQLText(
4388                                 'revision',
4389                                 '1',
4390                                 array( 'rev_page' => $this->getArticleID() ),
4391                                 __METHOD__,
4392                                 array( 'LIMIT' => $wgDeleteRevisionsLimit + 1 )
4393                         );
4394
4395                         $revCount = $dbr->query(
4396                                 'SELECT COUNT(*) FROM (' . $innerQuery . ') AS innerQuery',
4397                                 __METHOD__
4398                         );
4399                         $revCount = $revCount->fetchRow();
4400                         $revCount = $revCount['COUNT(*)'];
4401
4402                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4403                 }
4404
4405                 return $this->mIsBigDeletion;
4406         }
4407
4408         /**
4409          * Get the approximate revision count of this page.
4410          *
4411          * @return int
4412          */
4413         public function estimateRevisionCount() {
4414                 if ( !$this->exists() ) {
4415                         return 0;
4416                 }
4417
4418                 if ( $this->mEstimateRevisions === null ) {
4419                         $dbr = wfGetDB( DB_SLAVE );
4420                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4421                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4422                 }
4423
4424                 return $this->mEstimateRevisions;
4425         }
4426
4427         /**
4428          * Get the number of revisions between the given revision.
4429          * Used for diffs and other things that really need it.
4430          *
4431          * @param int|Revision $old Old revision or rev ID (first before range)
4432          * @param int|Revision $new New revision or rev ID (first after range)
4433          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4434          * @return int Number of revisions between these revisions.
4435          */
4436         public function countRevisionsBetween( $old, $new, $max = null ) {
4437                 if ( !( $old instanceof Revision ) ) {
4438                         $old = Revision::newFromTitle( $this, (int)$old );
4439                 }
4440                 if ( !( $new instanceof Revision ) ) {
4441                         $new = Revision::newFromTitle( $this, (int)$new );
4442                 }
4443                 if ( !$old || !$new ) {
4444                         return 0; // nothing to compare
4445                 }
4446                 $dbr = wfGetDB( DB_SLAVE );
4447                 $conds = array(
4448                         'rev_page' => $this->getArticleID(),
4449                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4450                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4451                 );
4452                 if ( $max !== null ) {
4453                         $res = $dbr->select( 'revision', '1',
4454                                 $conds,
4455                                 __METHOD__,
4456                                 array( 'LIMIT' => $max + 1 ) // extra to detect truncation
4457                         );
4458                         return $res->numRows();
4459                 } else {
4460                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4461                 }
4462         }
4463
4464         /**
4465          * Get the authors between the given revisions or revision IDs.
4466          * Used for diffs and other things that really need it.
4467          *
4468          * @since 1.23
4469          *
4470          * @param int|Revision $old Old revision or rev ID (first before range by default)
4471          * @param int|Revision $new New revision or rev ID (first after range by default)
4472          * @param int $limit Maximum number of authors
4473          * @param string|array $options (Optional): Single option, or an array of options:
4474          *     'include_old' Include $old in the range; $new is excluded.
4475          *     'include_new' Include $new in the range; $old is excluded.
4476          *     'include_both' Include both $old and $new in the range.
4477          *     Unknown option values are ignored.
4478          * @return array|null Names of revision authors in the range; null if not both revisions exist
4479          */
4480         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4481                 if ( !( $old instanceof Revision ) ) {
4482                         $old = Revision::newFromTitle( $this, (int)$old );
4483                 }
4484                 if ( !( $new instanceof Revision ) ) {
4485                         $new = Revision::newFromTitle( $this, (int)$new );
4486                 }
4487                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4488                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4489                 // in the sanity check below?
4490                 if ( !$old || !$new ) {
4491                         return null; // nothing to compare
4492                 }
4493                 $authors = array();
4494                 $old_cmp = '>';
4495                 $new_cmp = '<';
4496                 $options = (array)$options;
4497                 if ( in_array( 'include_old', $options ) ) {
4498                         $old_cmp = '>=';
4499                 }
4500                 if ( in_array( 'include_new', $options ) ) {
4501                         $new_cmp = '<=';
4502                 }
4503                 if ( in_array( 'include_both', $options ) ) {
4504                         $old_cmp = '>=';
4505                         $new_cmp = '<=';
4506                 }
4507                 // No DB query needed if $old and $new are the same or successive revisions:
4508                 if ( $old->getId() === $new->getId() ) {
4509                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? array() : array( $old->getRawUserText() );
4510                 } elseif ( $old->getId() === $new->getParentId() ) {
4511                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4512                                 $authors[] = $old->getRawUserText();
4513                                 if ( $old->getRawUserText() != $new->getRawUserText() ) {
4514                                         $authors[] = $new->getRawUserText();
4515                                 }
4516                         } elseif ( $old_cmp === '>=' ) {
4517                                 $authors[] = $old->getRawUserText();
4518                         } elseif ( $new_cmp === '<=' ) {
4519                                 $authors[] = $new->getRawUserText();
4520                         }
4521                         return $authors;
4522                 }
4523                 $dbr = wfGetDB( DB_SLAVE );
4524                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4525                         array(
4526                                 'rev_page' => $this->getArticleID(),
4527                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4528                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4529                         ), __METHOD__,
4530                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4531                 );
4532                 foreach ( $res as $row ) {
4533                         $authors[] = $row->rev_user_text;
4534                 }
4535                 return $authors;
4536         }
4537
4538         /**
4539          * Get the number of authors between the given revisions or revision IDs.
4540          * Used for diffs and other things that really need it.
4541          *
4542          * @param int|Revision $old Old revision or rev ID (first before range by default)
4543          * @param int|Revision $new New revision or rev ID (first after range by default)
4544          * @param int $limit Maximum number of authors
4545          * @param string|array $options (Optional): Single option, or an array of options:
4546          *     'include_old' Include $old in the range; $new is excluded.
4547          *     'include_new' Include $new in the range; $old is excluded.
4548          *     'include_both' Include both $old and $new in the range.
4549          *     Unknown option values are ignored.
4550          * @return int Number of revision authors in the range; zero if not both revisions exist
4551          */
4552         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4553                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4554                 return $authors ? count( $authors ) : 0;
4555         }
4556
4557         /**
4558          * Compare with another title.
4559          *
4560          * @param Title $title
4561          * @return bool
4562          */
4563         public function equals( Title $title ) {
4564                 // Note: === is necessary for proper matching of number-like titles.
4565                 return $this->getInterwiki() === $title->getInterwiki()
4566                         && $this->getNamespace() == $title->getNamespace()
4567                         && $this->getDBkey() === $title->getDBkey();
4568         }
4569
4570         /**
4571          * Check if this title is a subpage of another title
4572          *
4573          * @param Title $title
4574          * @return bool
4575          */
4576         public function isSubpageOf( Title $title ) {
4577                 return $this->getInterwiki() === $title->getInterwiki()
4578                         && $this->getNamespace() == $title->getNamespace()
4579                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4580         }
4581
4582         /**
4583          * Check if page exists.  For historical reasons, this function simply
4584          * checks for the existence of the title in the page table, and will
4585          * thus return false for interwiki links, special pages and the like.
4586          * If you want to know if a title can be meaningfully viewed, you should
4587          * probably call the isKnown() method instead.
4588          *
4589          * @return bool
4590          */
4591         public function exists() {
4592                 return $this->getArticleID() != 0;
4593         }
4594
4595         /**
4596          * Should links to this title be shown as potentially viewable (i.e. as
4597          * "bluelinks"), even if there's no record by this title in the page
4598          * table?
4599          *
4600          * This function is semi-deprecated for public use, as well as somewhat
4601          * misleadingly named.  You probably just want to call isKnown(), which
4602          * calls this function internally.
4603          *
4604          * (ISSUE: Most of these checks are cheap, but the file existence check
4605          * can potentially be quite expensive.  Including it here fixes a lot of
4606          * existing code, but we might want to add an optional parameter to skip
4607          * it and any other expensive checks.)
4608          *
4609          * @return bool
4610          */
4611         public function isAlwaysKnown() {
4612                 $isKnown = null;
4613
4614                 /**
4615                  * Allows overriding default behavior for determining if a page exists.
4616                  * If $isKnown is kept as null, regular checks happen. If it's
4617                  * a boolean, this value is returned by the isKnown method.
4618                  *
4619                  * @since 1.20
4620                  *
4621                  * @param Title $title
4622                  * @param bool|null $isKnown
4623                  */
4624                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4625
4626                 if ( !is_null( $isKnown ) ) {
4627                         return $isKnown;
4628                 }
4629
4630                 if ( $this->isExternal() ) {
4631                         return true;  // any interwiki link might be viewable, for all we know
4632                 }
4633
4634                 switch ( $this->mNamespace ) {
4635                         case NS_MEDIA:
4636                         case NS_FILE:
4637                                 // file exists, possibly in a foreign repo
4638                                 return (bool)wfFindFile( $this );
4639                         case NS_SPECIAL:
4640                                 // valid special page
4641                                 return SpecialPageFactory::exists( $this->getDBkey() );
4642                         case NS_MAIN:
4643                                 // selflink, possibly with fragment
4644                                 return $this->mDbkeyform == '';
4645                         case NS_MEDIAWIKI:
4646                                 // known system message
4647                                 return $this->hasSourceText() !== false;
4648                         default:
4649                                 return false;
4650                 }
4651         }
4652
4653         /**
4654          * Does this title refer to a page that can (or might) be meaningfully
4655          * viewed?  In particular, this function may be used to determine if
4656          * links to the title should be rendered as "bluelinks" (as opposed to
4657          * "redlinks" to non-existent pages).
4658          * Adding something else to this function will cause inconsistency
4659          * since LinkHolderArray calls isAlwaysKnown() and does its own
4660          * page existence check.
4661          *
4662          * @return bool
4663          */
4664         public function isKnown() {
4665                 return $this->isAlwaysKnown() || $this->exists();
4666         }
4667
4668         /**
4669          * Does this page have source text?
4670          *
4671          * @return bool
4672          */
4673         public function hasSourceText() {
4674                 if ( $this->exists() ) {
4675                         return true;
4676                 }
4677
4678                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4679                         // If the page doesn't exist but is a known system message, default
4680                         // message content will be displayed, same for language subpages-
4681                         // Use always content language to avoid loading hundreds of languages
4682                         // to get the link color.
4683                         global $wgContLang;
4684                         list( $name, ) = MessageCache::singleton()->figureMessage(
4685                                 $wgContLang->lcfirst( $this->getText() )
4686                         );
4687                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4688                         return $message->exists();
4689                 }
4690
4691                 return false;
4692         }
4693
4694         /**
4695          * Get the default message text or false if the message doesn't exist
4696          *
4697          * @return string|bool
4698          */
4699         public function getDefaultMessageText() {
4700                 global $wgContLang;
4701
4702                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4703                         return false;
4704                 }
4705
4706                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4707                         $wgContLang->lcfirst( $this->getText() )
4708                 );
4709                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4710
4711                 if ( $message->exists() ) {
4712                         return $message->plain();
4713                 } else {
4714                         return false;
4715                 }
4716         }
4717
4718         /**
4719          * Updates page_touched for this page; called from LinksUpdate.php
4720          *
4721          * @return bool True if the update succeeded
4722          */
4723         public function invalidateCache() {
4724                 if ( wfReadOnly() ) {
4725                         return false;
4726                 }
4727
4728                 if ( $this->mArticleID === 0 ) {
4729                         return true; // avoid gap locking if we know it's not there
4730                 }
4731
4732                 $method = __METHOD__;
4733                 $dbw = wfGetDB( DB_MASTER );
4734                 $conds = $this->pageCond();
4735                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method ) {
4736                         $dbw->update(
4737                                 'page',
4738                                 array( 'page_touched' => $dbw->timestamp() ),
4739                                 $conds,
4740                                 $method
4741                         );
4742                 } );
4743
4744                 return true;
4745         }
4746
4747         /**
4748          * Update page_touched timestamps and send squid purge messages for
4749          * pages linking to this title. May be sent to the job queue depending
4750          * on the number of links. Typically called on create and delete.
4751          */
4752         public function touchLinks() {
4753                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4754                 $u->doUpdate();
4755
4756                 if ( $this->getNamespace() == NS_CATEGORY ) {
4757                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4758                         $u->doUpdate();
4759                 }
4760         }
4761
4762         /**
4763          * Get the last touched timestamp
4764          *
4765          * @param DatabaseBase $db Optional db
4766          * @return string Last-touched timestamp
4767          */
4768         public function getTouched( $db = null ) {
4769                 if ( $db === null ) {
4770                         $db = wfGetDB( DB_SLAVE );
4771                 }
4772                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4773                 return $touched;
4774         }
4775
4776         /**
4777          * Get the timestamp when this page was updated since the user last saw it.
4778          *
4779          * @param User $user
4780          * @return string|null
4781          */
4782         public function getNotificationTimestamp( $user = null ) {
4783                 global $wgUser, $wgShowUpdatedMarker;
4784                 // Assume current user if none given
4785                 if ( !$user ) {
4786                         $user = $wgUser;
4787                 }
4788                 // Check cache first
4789                 $uid = $user->getId();
4790                 // avoid isset here, as it'll return false for null entries
4791                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4792                         return $this->mNotificationTimestamp[$uid];
4793                 }
4794                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4795                         $this->mNotificationTimestamp[$uid] = false;
4796                         return $this->mNotificationTimestamp[$uid];
4797                 }
4798                 // Don't cache too much!
4799                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4800                         $this->mNotificationTimestamp = array();
4801                 }
4802                 $dbr = wfGetDB( DB_SLAVE );
4803                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4804                         'wl_notificationtimestamp',
4805                         array(
4806                                 'wl_user' => $user->getId(),
4807                                 'wl_namespace' => $this->getNamespace(),
4808                                 'wl_title' => $this->getDBkey(),
4809                         ),
4810                         __METHOD__
4811                 );
4812                 return $this->mNotificationTimestamp[$uid];
4813         }
4814
4815         /**
4816          * Generate strings used for xml 'id' names in monobook tabs
4817          *
4818          * @param string $prepend Defaults to 'nstab-'
4819          * @return string XML 'id' name
4820          */
4821         public function getNamespaceKey( $prepend = 'nstab-' ) {
4822                 global $wgContLang;
4823                 // Gets the subject namespace if this title
4824                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4825                 // Checks if canonical namespace name exists for namespace
4826                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4827                         // Uses canonical namespace name
4828                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4829                 } else {
4830                         // Uses text of namespace
4831                         $namespaceKey = $this->getSubjectNsText();
4832                 }
4833                 // Makes namespace key lowercase
4834                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4835                 // Uses main
4836                 if ( $namespaceKey == '' ) {
4837                         $namespaceKey = 'main';
4838                 }
4839                 // Changes file to image for backwards compatibility
4840                 if ( $namespaceKey == 'file' ) {
4841                         $namespaceKey = 'image';
4842                 }
4843                 return $prepend . $namespaceKey;
4844         }
4845
4846         /**
4847          * Get all extant redirects to this Title
4848          *
4849          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4850          * @return Title[] Array of Title redirects to this title
4851          */
4852         public function getRedirectsHere( $ns = null ) {
4853                 $redirs = array();
4854
4855                 $dbr = wfGetDB( DB_SLAVE );
4856                 $where = array(
4857                         'rd_namespace' => $this->getNamespace(),
4858                         'rd_title' => $this->getDBkey(),
4859                         'rd_from = page_id'
4860                 );
4861                 if ( $this->isExternal() ) {
4862                         $where['rd_interwiki'] = $this->getInterwiki();
4863                 } else {
4864                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4865                 }
4866                 if ( !is_null( $ns ) ) {
4867                         $where['page_namespace'] = $ns;
4868                 }
4869
4870                 $res = $dbr->select(
4871                         array( 'redirect', 'page' ),
4872                         array( 'page_namespace', 'page_title' ),
4873                         $where,
4874                         __METHOD__
4875                 );
4876
4877                 foreach ( $res as $row ) {
4878                         $redirs[] = self::newFromRow( $row );
4879                 }
4880                 return $redirs;
4881         }
4882
4883         /**
4884          * Check if this Title is a valid redirect target
4885          *
4886          * @return bool
4887          */
4888         public function isValidRedirectTarget() {
4889                 global $wgInvalidRedirectTargets;
4890
4891                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4892                 if ( $this->isSpecial( 'Userlogout' ) ) {
4893                         return false;
4894                 }
4895
4896                 foreach ( $wgInvalidRedirectTargets as $target ) {
4897                         if ( $this->isSpecial( $target ) ) {
4898                                 return false;
4899                         }
4900                 }
4901
4902                 return true;
4903         }
4904
4905         /**
4906          * Get a backlink cache object
4907          *
4908          * @return BacklinkCache
4909          */
4910         public function getBacklinkCache() {
4911                 return BacklinkCache::get( $this );
4912         }
4913
4914         /**
4915          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4916          *
4917          * @return bool
4918          */
4919         public function canUseNoindex() {
4920                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4921
4922                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4923                         ? $wgContentNamespaces
4924                         : $wgExemptFromUserRobotsControl;
4925
4926                 return !in_array( $this->mNamespace, $bannedNamespaces );
4927
4928         }
4929
4930         /**
4931          * Returns the raw sort key to be used for categories, with the specified
4932          * prefix.  This will be fed to Collation::getSortKey() to get a
4933          * binary sortkey that can be used for actual sorting.
4934          *
4935          * @param string $prefix The prefix to be used, specified using
4936          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4937          *   prefix.
4938          * @return string
4939          */
4940         public function getCategorySortkey( $prefix = '' ) {
4941                 $unprefixed = $this->getText();
4942
4943                 // Anything that uses this hook should only depend
4944                 // on the Title object passed in, and should probably
4945                 // tell the users to run updateCollations.php --force
4946                 // in order to re-sort existing category relations.
4947                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4948                 if ( $prefix !== '' ) {
4949                         # Separate with a line feed, so the unprefixed part is only used as
4950                         # a tiebreaker when two pages have the exact same prefix.
4951                         # In UCA, tab is the only character that can sort above LF
4952                         # so we strip both of them from the original prefix.
4953                         $prefix = strtr( $prefix, "\n\t", '  ' );
4954                         return "$prefix\n$unprefixed";
4955                 }
4956                 return $unprefixed;
4957         }
4958
4959         /**
4960          * Get the language in which the content of this page is written in
4961          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4962          * e.g. $wgLang (such as special pages, which are in the user language).
4963          *
4964          * @since 1.18
4965          * @return Language
4966          */
4967         public function getPageLanguage() {
4968                 global $wgLang, $wgLanguageCode;
4969                 wfProfileIn( __METHOD__ );
4970                 if ( $this->isSpecialPage() ) {
4971                         // special pages are in the user language
4972                         wfProfileOut( __METHOD__ );
4973                         return $wgLang;
4974                 }
4975
4976                 // Checking if DB language is set
4977                 if ( $this->mDbPageLanguage ) {
4978                         wfProfileOut( __METHOD__ );
4979                         return wfGetLangObj( $this->mDbPageLanguage );
4980                 }
4981
4982                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4983                         // Note that this may depend on user settings, so the cache should
4984                         // be only per-request.
4985                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4986                         // content to determine the page language!
4987                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4988                         // tests.
4989                         $contentHandler = ContentHandler::getForTitle( $this );
4990                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4991                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4992                 } else {
4993                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4994                 }
4995
4996                 wfProfileOut( __METHOD__ );
4997                 return $langObj;
4998         }
4999
5000         /**
5001          * Get the language in which the content of this page is written when
5002          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
5003          * e.g. $wgLang (such as special pages, which are in the user language).
5004          *
5005          * @since 1.20
5006          * @return Language
5007          */
5008         public function getPageViewLanguage() {
5009                 global $wgLang;
5010
5011                 if ( $this->isSpecialPage() ) {
5012                         // If the user chooses a variant, the content is actually
5013                         // in a language whose code is the variant code.
5014                         $variant = $wgLang->getPreferredVariant();
5015                         if ( $wgLang->getCode() !== $variant ) {
5016                                 return Language::factory( $variant );
5017                         }
5018
5019                         return $wgLang;
5020                 }
5021
5022                 // @note Can't be cached persistently, depends on user settings.
5023                 // @note ContentHandler::getPageViewLanguage() may need to load the
5024                 //   content to determine the page language!
5025                 $contentHandler = ContentHandler::getForTitle( $this );
5026                 $pageLang = $contentHandler->getPageViewLanguage( $this );
5027                 return $pageLang;
5028         }
5029
5030         /**
5031          * Get a list of rendered edit notices for this page.
5032          *
5033          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
5034          * they will already be wrapped in paragraphs.
5035          *
5036          * @since 1.21
5037          * @param int $oldid Revision ID that's being edited
5038          * @return array
5039          */
5040         public function getEditNotices( $oldid = 0 ) {
5041                 $notices = array();
5042
5043                 # Optional notices on a per-namespace and per-page basis
5044                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
5045                 $editnotice_ns_message = wfMessage( $editnotice_ns );
5046                 if ( $editnotice_ns_message->exists() ) {
5047                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
5048                 }
5049                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
5050                         $parts = explode( '/', $this->getDBkey() );
5051                         $editnotice_base = $editnotice_ns;
5052                         while ( count( $parts ) > 0 ) {
5053                                 $editnotice_base .= '-' . array_shift( $parts );
5054                                 $editnotice_base_msg = wfMessage( $editnotice_base );
5055                                 if ( $editnotice_base_msg->exists() ) {
5056                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
5057                                 }
5058                         }
5059                 } else {
5060                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
5061                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
5062                         $editnoticeMsg = wfMessage( $editnoticeText );
5063                         if ( $editnoticeMsg->exists() ) {
5064                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
5065                         }
5066                 }
5067
5068                 wfRunHooks( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
5069                 return $notices;
5070         }
5071 }