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 use MediaWiki\Linker\LinkTarget;
  25
  26 /**
  27  * Represents a title within MediaWiki.
  28  * Optionally may contain an interwiki designation or namespace.
  29  * @note This class can fetch various kinds of data from the database;
  30  *       however, it does so inefficiently.
  31  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  32  *       and does not rely on global state or the database.
  33  */
  34 class Title implements LinkTarget {
  35         /** @var HashBagOStuff */
  36         static private $titleCache = null;
  37
  38         /**
  39          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  40          * commonly used titles. On a batch operation this can become a memory leak
  41          * if not bounded. After hitting this many titles reset the cache.
  42          */
  43         const CACHE_MAX = 1000;
  44
  45         /**
  46          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  47          * to use the master DB
  48          */
  49         const GAID_FOR_UPDATE = 1;
  50
  51         /**
  52          * @name Private member variables
  53          * Please use the accessor functions instead.
  54          * @private
  55          */
  56         // @{
  57
  58         /** @var string Text form (spaces not underscores) of the main part */
  59         public $mTextform = '';
  60
  61         /** @var string URL-encoded form of the main part */
  62         public $mUrlform = '';
  63
  64         /** @var string Main part with underscores */
  65         public $mDbkeyform = '';
  66
  67         /** @var string Database key with the initial letter in the case specified by the user */
  68         protected $mUserCaseDBKey;
  69
  70         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  71         public $mNamespace = NS_MAIN;
  72
  73         /** @var string Interwiki prefix */
  74         public $mInterwiki = '';
  75
  76         /** @var bool Was this Title created from a string with a local interwiki prefix? */
  77         private $mLocalInterwiki = false;
  78
  79         /** @var string Title fragment (i.e. the bit after the #) */
  80         public $mFragment = '';
  81
  82         /** @var int Article ID, fetched from the link cache on demand */
  83         public $mArticleID = -1;
  84
  85         /** @var bool|int ID of most recent revision */
  86         protected $mLatestID = false;
  87
  88         /**
  89          * @var bool|string ID of the page's content model, i.e. one of the
  90          *   CONTENT_MODEL_XXX constants
  91          */
  92         public $mContentModel = false;
  93
  94         /** @var int Estimated number of revisions; null of not loaded */
  95         private $mEstimateRevisions;
  96
  97         /** @var array Array of groups allowed to edit this article */
  98         public $mRestrictions = [];
  99
 100         /** @var string|bool */
 101         protected $mOldRestrictions = false;
 102
 103         /** @var bool Cascade restrictions on this page to included templates and images? */
 104         public $mCascadeRestriction;
 105
 106         /** Caching the results of getCascadeProtectionSources */
 107         public $mCascadingRestrictions;
 108
 109         /** @var array When do the restrictions on this page expire? */
 110         protected $mRestrictionsExpiry = [];
 111
 112         /** @var bool Are cascading restrictions in effect on this page? */
 113         protected $mHasCascadingRestrictions;
 114
 115         /** @var array Where are the cascading restrictions coming from on this page? */
 116         public $mCascadeSources;
 117
 118         /** @var bool Boolean for initialisation on demand */
 119         public $mRestrictionsLoaded = false;
 120
 121         /** @var string Text form including namespace/interwiki, initialised on demand */
 122         protected $mPrefixedText = null;
 123
 124         /** @var mixed Cached value for getTitleProtection (create protection) */
 125         public $mTitleProtection;
 126
 127         /**
 128          * @var int Namespace index when there is no namespace. Don't change the
 129          *   following default, NS_MAIN is hardcoded in several places. See bug 696.
 130          *   Zero except in {{transclusion}} tags.
 131          */
 132         public $mDefaultNamespace = NS_MAIN;
 133
 134         /** @var int The page length, 0 for special pages */
 135         protected $mLength = -1;
 136
 137         /** @var null Is the article at this title a redirect? */
 138         public $mRedirect = null;
 139
 140         /** @var array Associative array of user ID -> timestamp/false */
 141         private $mNotificationTimestamp = [];
 142
 143         /** @var bool Whether a page has any subpages */
 144         private $mHasSubpages;
 145
 146         /** @var bool The (string) language code of the page's language and content code. */
 147         private $mPageLanguage = false;
 148
 149         /** @var string|bool|null The page language code from the database, null if not saved in
 150          * the database or false if not loaded, yet. */
 151         private $mDbPageLanguage = false;
 152
 153         /** @var TitleValue A corresponding TitleValue object */
 154         private $mTitleValue = null;
 155
 156         /** @var bool Would deleting this page be a big deletion? */
 157         private $mIsBigDeletion = null;
 158         // @}
 159
 160         /**
 161          * B/C kludge: provide a TitleParser for use by Title.
 162          * Ideally, Title would have no methods that need this.
 163          * Avoid usage of this singleton by using TitleValue
 164          * and the associated services when possible.
 165          *
 166          * @return MediaWikiTitleCodec
 167          */
 168         private static function getMediaWikiTitleCodec() {
 169                 global $wgContLang, $wgLocalInterwikis;
 170
 171                 static $titleCodec = null;
 172                 static $titleCodecFingerprint = null;
 173
 174                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 175                 // make sure we are using the right one. To detect changes over the course
 176                 // of a request, we remember a fingerprint of the config used to create the
 177                 // codec singleton, and re-create it if the fingerprint doesn't match.
 178                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . implode( '+', $wgLocalInterwikis );
 179
 180                 if ( $fingerprint !== $titleCodecFingerprint ) {
 181                         $titleCodec = null;
 182                 }
 183
 184                 if ( !$titleCodec ) {
 185                         $titleCodec = new MediaWikiTitleCodec(
 186                                 $wgContLang,
 187                                 GenderCache::singleton(),
 188                                 $wgLocalInterwikis
 189                         );
 190                         $titleCodecFingerprint = $fingerprint;
 191                 }
 192
 193                 return $titleCodec;
 194         }
 195
 196         /**
 197          * B/C kludge: provide a TitleParser for use by Title.
 198          * Ideally, Title would have no methods that need this.
 199          * Avoid usage of this singleton by using TitleValue
 200          * and the associated services when possible.
 201          *
 202          * @return TitleFormatter
 203          */
 204         private static function getTitleFormatter() {
 205                 // NOTE: we know that getMediaWikiTitleCodec() returns a MediaWikiTitleCodec,
 206                 //      which implements TitleFormatter.
 207                 return self::getMediaWikiTitleCodec();
 208         }
 209
 210         function __construct() {
 211         }
 212
 213         /**
 214          * Create a new Title from a prefixed DB key
 215          *
 216          * @param string $key The database key, which has underscores
 217          *      instead of spaces, possibly including namespace and
 218          *      interwiki prefixes
 219          * @return Title|null Title, or null on an error
 220          */
 221         public static function newFromDBkey( $key ) {
 222                 $t = new Title();
 223                 $t->mDbkeyform = $key;
 224
 225                 try {
 226                         $t->secureAndSplit();
 227                         return $t;
 228                 } catch ( MalformedTitleException $ex ) {
 229                         return null;
 230                 }
 231         }
 232
 233         /**
 234          * Create a new Title from a TitleValue
 235          *
 236          * @param TitleValue $titleValue Assumed to be safe.
 237          *
 238          * @return Title
 239          */
 240         public static function newFromTitleValue( TitleValue $titleValue ) {
 241                 return self::newFromLinkTarget( $titleValue );
 242         }
 243
 244         /**
 245          * Create a new Title from a LinkTarget
 246          *
 247          * @param LinkTarget $linkTarget Assumed to be safe.
 248          *
 249          * @return Title
 250          */
 251         public static function newFromLinkTarget( LinkTarget $linkTarget ) {
 252                 if ( $linkTarget instanceof Title ) {
 253                         // Special case if it's already a Title object
 254                         return $linkTarget;
 255                 }
 256                 return self::makeTitle(
 257                         $linkTarget->getNamespace(),
 258                         $linkTarget->getText(),
 259                         $linkTarget->getFragment(),
 260                         $linkTarget->getInterwiki()
 261                 );
 262         }
 263
 264         /**
 265          * Create a new Title from text, such as what one would find in a link. De-
 266          * codes any HTML entities in the text.
 267          *
 268          * @param string|int|null $text The link text; spaces, prefixes, and an
 269          *   initial ':' indicating the main namespace are accepted.
 270          * @param int $defaultNamespace The namespace to use if none is specified
 271          *   by a prefix.  If you want to force a specific namespace even if
 272          *   $text might begin with a namespace prefix, use makeTitle() or
 273          *   makeTitleSafe().
 274          * @throws InvalidArgumentException
 275          * @return Title|null Title or null on an error.
 276          */
 277         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 278                 // DWIM: Integers can be passed in here when page titles are used as array keys.
 279                 if ( $text !== null && !is_string( $text ) && !is_int( $text ) ) {
 280                         throw new InvalidArgumentException( '$text must be a string.' );
 281                 }
 282                 if ( $text === null ) {
 283                         return null;
 284                 }
 285
 286                 try {
 287                         return Title::newFromTextThrow( strval( $text ), $defaultNamespace );
 288                 } catch ( MalformedTitleException $ex ) {
 289                         return null;
 290                 }
 291         }
 292
 293         /**
 294          * Like Title::newFromText(), but throws MalformedTitleException when the title is invalid,
 295          * rather than returning null.
 296          *
 297          * The exception subclasses encode detailed information about why the title is invalid.
 298          *
 299          * @see Title::newFromText
 300          *
 301          * @since 1.25
 302          * @param string $text Title text to check
 303          * @param int $defaultNamespace
 304          * @throws MalformedTitleException If the title is invalid
 305          * @return Title
 306          */
 307         public static function newFromTextThrow( $text, $defaultNamespace = NS_MAIN ) {
 308                 if ( is_object( $text ) ) {
 309                         throw new MWException( '$text must be a string, given an object' );
 310                 }
 311
 312                 $titleCache = self::getTitleCache();
 313
 314                 // Wiki pages often contain multiple links to the same page.
 315                 // Title normalization and parsing can become expensive on pages with many
 316                 // links, so we can save a little time by caching them.
 317                 // In theory these are value objects and won't get changed...
 318                 if ( $defaultNamespace == NS_MAIN ) {
 319                         $t = $titleCache->get( $text );
 320                         if ( $t ) {
 321                                 return $t;
 322                         }
 323                 }
 324
 325                 // Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 326                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 327
 328                 $t = new Title();
 329                 $t->mDbkeyform = strtr( $filteredText, ' ', '_' );
 330                 $t->mDefaultNamespace = intval( $defaultNamespace );
 331
 332                 $t->secureAndSplit();
 333                 if ( $defaultNamespace == NS_MAIN ) {
 334                         $titleCache->set( $text, $t );
 335                 }
 336                 return $t;
 337         }
 338
 339         /**
 340          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 341          *
 342          * Example of wrong and broken code:
 343          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 344          *
 345          * Example of right code:
 346          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 347          *
 348          * Create a new Title from URL-encoded text. Ensures that
 349          * the given title's length does not exceed the maximum.
 350          *
 351          * @param string $url The title, as might be taken from a URL
 352          * @return Title|null The new object, or null on an error
 353          */
 354         public static function newFromURL( $url ) {
 355                 $t = new Title();
 356
 357                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 358                 # but some URLs used it as a space replacement and they still come
 359                 # from some external search tools.
 360                 if ( strpos( self::legalChars(), '+' ) === false ) {
 361                         $url = strtr( $url, '+', ' ' );
 362                 }
 363
 364                 $t->mDbkeyform = strtr( $url, ' ', '_' );
 365
 366                 try {
 367                         $t->secureAndSplit();
 368                         return $t;
 369                 } catch ( MalformedTitleException $ex ) {
 370                         return null;
 371                 }
 372         }
 373
 374         /**
 375          * @return HashBagOStuff
 376          */
 377         private static function getTitleCache() {
 378                 if ( self::$titleCache == null ) {
 379                         self::$titleCache = new HashBagOStuff( [ 'maxKeys' => self::CACHE_MAX ] );
 380                 }
 381                 return self::$titleCache;
 382         }
 383
 384         /**
 385          * Returns a list of fields that are to be selected for initializing Title
 386          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 387          * whether to include page_content_model.
 388          *
 389          * @return array
 390          */
 391         protected static function getSelectFields() {
 392                 global $wgContentHandlerUseDB, $wgPageLanguageUseDB;
 393
 394                 $fields = [
 395                         'page_namespace', 'page_title', 'page_id',
 396                         'page_len', 'page_is_redirect', 'page_latest',
 397                 ];
 398
 399                 if ( $wgContentHandlerUseDB ) {
 400                         $fields[] = 'page_content_model';
 401                 }
 402
 403                 if ( $wgPageLanguageUseDB ) {
 404                         $fields[] = 'page_lang';
 405                 }
 406
 407                 return $fields;
 408         }
 409
 410         /**
 411          * Create a new Title from an article ID
 412          *
 413          * @param int $id The page_id corresponding to the Title to create
 414          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 415          * @return Title|null The new object, or null on an error
 416          */
 417         public static function newFromID( $id, $flags = 0 ) {
 418                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 419                 $row = $db->selectRow(
 420                         'page',
 421                         self::getSelectFields(),
 422                         [ 'page_id' => $id ],
 423                         __METHOD__
 424                 );
 425                 if ( $row !== false ) {
 426                         $title = Title::newFromRow( $row );
 427                 } else {
 428                         $title = null;
 429                 }
 430                 return $title;
 431         }
 432
 433         /**
 434          * Make an array of titles from an array of IDs
 435          *
 436          * @param int[] $ids Array of IDs
 437          * @return Title[] Array of Titles
 438          */
 439         public static function newFromIDs( $ids ) {
 440                 if ( !count( $ids ) ) {
 441                         return [];
 442                 }
 443                 $dbr = wfGetDB( DB_SLAVE );
 444
 445                 $res = $dbr->select(
 446                         'page',
 447                         self::getSelectFields(),
 448                         [ 'page_id' => $ids ],
 449                         __METHOD__
 450                 );
 451
 452                 $titles = [];
 453                 foreach ( $res as $row ) {
 454                         $titles[] = Title::newFromRow( $row );
 455                 }
 456                 return $titles;
 457         }
 458
 459         /**
 460          * Make a Title object from a DB row
 461          *
 462          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 463          * @return Title Corresponding Title
 464          */
 465         public static function newFromRow( $row ) {
 466                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 467                 $t->loadFromRow( $row );
 468                 return $t;
 469         }
 470
 471         /**
 472          * Load Title object fields from a DB row.
 473          * If false is given, the title will be treated as non-existing.
 474          *
 475          * @param stdClass|bool $row Database row
 476          */
 477         public function loadFromRow( $row ) {
 478                 if ( $row ) { // page found
 479                         if ( isset( $row->page_id ) ) {
 480                                 $this->mArticleID = (int)$row->page_id;
 481                         }
 482                         if ( isset( $row->page_len ) ) {
 483                                 $this->mLength = (int)$row->page_len;
 484                         }
 485                         if ( isset( $row->page_is_redirect ) ) {
 486                                 $this->mRedirect = (bool)$row->page_is_redirect;
 487                         }
 488                         if ( isset( $row->page_latest ) ) {
 489                                 $this->mLatestID = (int)$row->page_latest;
 490                         }
 491                         if ( isset( $row->page_content_model ) ) {
 492                                 $this->mContentModel = strval( $row->page_content_model );
 493                         } else {
 494                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 495                         }
 496                         if ( isset( $row->page_lang ) ) {
 497                                 $this->mDbPageLanguage = (string)$row->page_lang;
 498                         }
 499                         if ( isset( $row->page_restrictions ) ) {
 500                                 $this->mOldRestrictions = $row->page_restrictions;
 501                         }
 502                 } else { // page not found
 503                         $this->mArticleID = 0;
 504                         $this->mLength = 0;
 505                         $this->mRedirect = false;
 506                         $this->mLatestID = 0;
 507                         $this->mContentModel = false; # initialized lazily in getContentModel()
 508                 }
 509         }
 510
 511         /**
 512          * Create a new Title from a namespace index and a DB key.
 513          * It's assumed that $ns and $title are *valid*, for instance when
 514          * they came directly from the database or a special page name.
 515          * For convenience, spaces are converted to underscores so that
 516          * eg user_text fields can be used directly.
 517          *
 518          * @param int $ns The namespace of the article
 519          * @param string $title The unprefixed database key form
 520          * @param string $fragment The link fragment (after the "#")
 521          * @param string $interwiki The interwiki prefix
 522          * @return Title The new object
 523          */
 524         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 525                 $t = new Title();
 526                 $t->mInterwiki = $interwiki;
 527                 $t->mFragment = $fragment;
 528                 $t->mNamespace = $ns = intval( $ns );
 529                 $t->mDbkeyform = strtr( $title, ' ', '_' );
 530                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 531                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 532                 $t->mTextform = strtr( $title, '_', ' ' );
 533                 $t->mContentModel = false; # initialized lazily in getContentModel()
 534                 return $t;
 535         }
 536
 537         /**
 538          * Create a new Title from a namespace index and a DB key.
 539          * The parameters will be checked for validity, which is a bit slower
 540          * than makeTitle() but safer for user-provided data.
 541          *
 542          * @param int $ns The namespace of the article
 543          * @param string $title Database key form
 544          * @param string $fragment The link fragment (after the "#")
 545          * @param string $interwiki Interwiki prefix
 546          * @return Title|null The new object, or null on an error
 547          */
 548         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 549                 if ( !MWNamespace::exists( $ns ) ) {
 550                         return null;
 551                 }
 552
 553                 $t = new Title();
 554                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 555
 556                 try {
 557                         $t->secureAndSplit();
 558                         return $t;
 559                 } catch ( MalformedTitleException $ex ) {
 560                         return null;
 561                 }
 562         }
 563
 564         /**
 565          * Create a new Title for the Main Page
 566          *
 567          * @return Title The new object
 568          */
 569         public static function newMainPage() {
 570                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 571                 // Don't give fatal errors if the message is broken
 572                 if ( !$title ) {
 573                         $title = Title::newFromText( 'Main Page' );
 574                 }
 575                 return $title;
 576         }
 577
 578         /**
 579          * Get the prefixed DB key associated with an ID
 580          *
 581          * @param int $id The page_id of the article
 582          * @return Title|null An object representing the article, or null if no such article was found
 583          */
 584         public static function nameOf( $id ) {
 585                 $dbr = wfGetDB( DB_SLAVE );
 586
 587                 $s = $dbr->selectRow(
 588                         'page',
 589                         [ 'page_namespace', 'page_title' ],
 590                         [ 'page_id' => $id ],
 591                         __METHOD__
 592                 );
 593                 if ( $s === false ) {
 594                         return null;
 595                 }
 596
 597                 $n = self::makeName( $s->page_namespace, $s->page_title );
 598                 return $n;
 599         }
 600
 601         /**
 602          * Get a regex character class describing the legal characters in a link
 603          *
 604          * @return string The list of characters, not delimited
 605          */
 606         public static function legalChars() {
 607                 global $wgLegalTitleChars;
 608                 return $wgLegalTitleChars;
 609         }
 610
 611         /**
 612          * Returns a simple regex that will match on characters and sequences invalid in titles.
 613          * Note that this doesn't pick up many things that could be wrong with titles, but that
 614          * replacing this regex with something valid will make many titles valid.
 615          *
 616          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 617          *
 618          * @return string Regex string
 619          */
 620         static function getTitleInvalidRegex() {
 621                 wfDeprecated( __METHOD__, '1.25' );
 622                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 623         }
 624
 625         /**
 626          * Utility method for converting a character sequence from bytes to Unicode.
 627          *
 628          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 629          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 630          *
 631          * @param string $byteClass
 632          * @return string
 633          */
 634         public static function convertByteClassToUnicodeClass( $byteClass ) {
 635                 $length = strlen( $byteClass );
 636                 // Input token queue
 637                 $x0 = $x1 = $x2 = '';
 638                 // Decoded queue
 639                 $d0 = $d1 = $d2 = '';
 640                 // Decoded integer codepoints
 641                 $ord0 = $ord1 = $ord2 = 0;
 642                 // Re-encoded queue
 643                 $r0 = $r1 = $r2 = '';
 644                 // Output
 645                 $out = '';
 646                 // Flags
 647                 $allowUnicode = false;
 648                 for ( $pos = 0; $pos < $length; $pos++ ) {
 649                         // Shift the queues down
 650                         $x2 = $x1;
 651                         $x1 = $x0;
 652                         $d2 = $d1;
 653                         $d1 = $d0;
 654                         $ord2 = $ord1;
 655                         $ord1 = $ord0;
 656                         $r2 = $r1;
 657                         $r1 = $r0;
 658                         // Load the current input token and decoded values
 659                         $inChar = $byteClass[$pos];
 660                         if ( $inChar == '\\' ) {
 661                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 662                                         $x0 = $inChar . $m[0];
 663                                         $d0 = chr( hexdec( $m[1] ) );
 664                                         $pos += strlen( $m[0] );
 665                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 666                                         $x0 = $inChar . $m[0];
 667                                         $d0 = chr( octdec( $m[0] ) );
 668                                         $pos += strlen( $m[0] );
 669                                 } elseif ( $pos + 1 >= $length ) {
 670                                         $x0 = $d0 = '\\';
 671                                 } else {
 672                                         $d0 = $byteClass[$pos + 1];
 673                                         $x0 = $inChar . $d0;
 674                                         $pos += 1;
 675                                 }
 676                         } else {
 677                                 $x0 = $d0 = $inChar;
 678                         }
 679                         $ord0 = ord( $d0 );
 680                         // Load the current re-encoded value
 681                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 682                                 $r0 = sprintf( '\x%02x', $ord0 );
 683                         } elseif ( $ord0 >= 0x80 ) {
 684                                 // Allow unicode if a single high-bit character appears
 685                                 $r0 = sprintf( '\x%02x', $ord0 );
 686                                 $allowUnicode = true;
 687                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 688                                 $r0 = '\\' . $d0;
 689                         } else {
 690                                 $r0 = $d0;
 691                         }
 692                         // Do the output
 693                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 694                                 // Range
 695                                 if ( $ord2 > $ord0 ) {
 696                                         // Empty range
 697                                 } elseif ( $ord0 >= 0x80 ) {
 698                                         // Unicode range
 699                                         $allowUnicode = true;
 700                                         if ( $ord2 < 0x80 ) {
 701                                                 // Keep the non-unicode section of the range
 702                                                 $out .= "$r2-\\x7F";
 703                                         }
 704                                 } else {
 705                                         // Normal range
 706                                         $out .= "$r2-$r0";
 707                                 }
 708                                 // Reset state to the initial value
 709                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 710                         } elseif ( $ord2 < 0x80 ) {
 711                                 // ASCII character
 712                                 $out .= $r2;
 713                         }
 714                 }
 715                 if ( $ord1 < 0x80 ) {
 716                         $out .= $r1;
 717                 }
 718                 if ( $ord0 < 0x80 ) {
 719                         $out .= $r0;
 720                 }
 721                 if ( $allowUnicode ) {
 722                         $out .= '\u0080-\uFFFF';
 723                 }
 724                 return $out;
 725         }
 726
 727         /**
 728          * Make a prefixed DB key from a DB key and a namespace index
 729          *
 730          * @param int $ns Numerical representation of the namespace
 731          * @param string $title The DB key form the title
 732          * @param string $fragment The link fragment (after the "#")
 733          * @param string $interwiki The interwiki prefix
 734          * @param bool $canonicalNamespace If true, use the canonical name for
 735          *   $ns instead of the localized version.
 736          * @return string The prefixed form of the title
 737          */
 738         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 739                 $canonicalNamespace = false
 740         ) {
 741                 global $wgContLang;
 742
 743                 if ( $canonicalNamespace ) {
 744                         $namespace = MWNamespace::getCanonicalName( $ns );
 745                 } else {
 746                         $namespace = $wgContLang->getNsText( $ns );
 747                 }
 748                 $name = $namespace == '' ? $title : "$namespace:$title";
 749                 if ( strval( $interwiki ) != '' ) {
 750                         $name = "$interwiki:$name";
 751                 }
 752                 if ( strval( $fragment ) != '' ) {
 753                         $name .= '#' . $fragment;
 754                 }
 755                 return $name;
 756         }
 757
 758         /**
 759          * Escape a text fragment, say from a link, for a URL
 760          *
 761          * @param string $fragment Containing a URL or link fragment (after the "#")
 762          * @return string Escaped string
 763          */
 764         static function escapeFragmentForURL( $fragment ) {
 765                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 766                 # fragments appear not to work in IE (at least up to 7) or in at least
 767                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 768                 # to care if they aren't encoded.
 769                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 770         }
 771
 772         /**
 773          * Callback for usort() to do title sorts by (namespace, title)
 774          *
 775          * @param Title $a
 776          * @param Title $b
 777          *
 778          * @return int Result of string comparison, or namespace comparison
 779          */
 780         public static function compare( $a, $b ) {
 781                 if ( $a->getNamespace() == $b->getNamespace() ) {
 782                         return strcmp( $a->getText(), $b->getText() );
 783                 } else {
 784                         return $a->getNamespace() - $b->getNamespace();
 785                 }
 786         }
 787
 788         /**
 789          * Determine whether the object refers to a page within
 790          * this project (either this wiki or a wiki with a local
 791          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 792          *
 793          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 794          */
 795         public function isLocal() {
 796                 if ( $this->isExternal() ) {
 797                         $iw = Interwiki::fetch( $this->mInterwiki );
 798                         if ( $iw ) {
 799                                 return $iw->isLocal();
 800                         }
 801                 }
 802                 return true;
 803         }
 804
 805         /**
 806          * Is this Title interwiki?
 807          *
 808          * @return bool
 809          */
 810         public function isExternal() {
 811                 return $this->mInterwiki !== '';
 812         }
 813
 814         /**
 815          * Get the interwiki prefix
 816          *
 817          * Use Title::isExternal to check if a interwiki is set
 818          *
 819          * @return string Interwiki prefix
 820          */
 821         public function getInterwiki() {
 822                 return $this->mInterwiki;
 823         }
 824
 825         /**
 826          * Was this a local interwiki link?
 827          *
 828          * @return bool
 829          */
 830         public function wasLocalInterwiki() {
 831                 return $this->mLocalInterwiki;
 832         }
 833
 834         /**
 835          * Determine whether the object refers to a page within
 836          * this project and is transcludable.
 837          *
 838          * @return bool True if this is transcludable
 839          */
 840         public function isTrans() {
 841                 if ( !$this->isExternal() ) {
 842                         return false;
 843                 }
 844
 845                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 846         }
 847
 848         /**
 849          * Returns the DB name of the distant wiki which owns the object.
 850          *
 851          * @return string The DB name
 852          */
 853         public function getTransWikiID() {
 854                 if ( !$this->isExternal() ) {
 855                         return false;
 856                 }
 857
 858                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 859         }
 860
 861         /**
 862          * Get a TitleValue object representing this Title.
 863          *
 864          * @note Not all valid Titles have a corresponding valid TitleValue
 865          * (e.g. TitleValues cannot represent page-local links that have a
 866          * fragment but no title text).
 867          *
 868          * @return TitleValue|null
 869          */
 870         public function getTitleValue() {
 871                 if ( $this->mTitleValue === null ) {
 872                         try {
 873                                 $this->mTitleValue = new TitleValue(
 874                                         $this->getNamespace(),
 875                                         $this->getDBkey(),
 876                                         $this->getFragment(),
 877                                         $this->getInterwiki()
 878                                 );
 879                         } catch ( InvalidArgumentException $ex ) {
 880                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 881                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 882                         }
 883                 }
 884
 885                 return $this->mTitleValue;
 886         }
 887
 888         /**
 889          * Get the text form (spaces not underscores) of the main part
 890          *
 891          * @return string Main part of the title
 892          */
 893         public function getText() {
 894                 return $this->mTextform;
 895         }
 896
 897         /**
 898          * Get the URL-encoded form of the main part
 899          *
 900          * @return string Main part of the title, URL-encoded
 901          */
 902         public function getPartialURL() {
 903                 return $this->mUrlform;
 904         }
 905
 906         /**
 907          * Get the main part with underscores
 908          *
 909          * @return string Main part of the title, with underscores
 910          */
 911         public function getDBkey() {
 912                 return $this->mDbkeyform;
 913         }
 914
 915         /**
 916          * Get the DB key with the initial letter case as specified by the user
 917          *
 918          * @return string DB key
 919          */
 920         function getUserCaseDBKey() {
 921                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 922                         return $this->mUserCaseDBKey;
 923                 } else {
 924                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 925                         return $this->mDbkeyform;
 926                 }
 927         }
 928
 929         /**
 930          * Get the namespace index, i.e. one of the NS_xxxx constants.
 931          *
 932          * @return int Namespace index
 933          */
 934         public function getNamespace() {
 935                 return $this->mNamespace;
 936         }
 937
 938         /**
 939          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 940          *
 941          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 942          * @return string Content model id
 943          */
 944         public function getContentModel( $flags = 0 ) {
 945                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 946                         $linkCache = LinkCache::singleton();
 947                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 948                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 949                 }
 950
 951                 if ( !$this->mContentModel ) {
 952                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 953                 }
 954
 955                 return $this->mContentModel;
 956         }
 957
 958         /**
 959          * Convenience method for checking a title's content model name
 960          *
 961          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 962          * @return bool True if $this->getContentModel() == $id
 963          */
 964         public function hasContentModel( $id ) {
 965                 return $this->getContentModel() == $id;
 966         }
 967
 968         /**
 969          * Get the namespace text
 970          *
 971          * @return string Namespace text
 972          */
 973         public function getNsText() {
 974                 if ( $this->isExternal() ) {
 975                         // This probably shouldn't even happen,
 976                         // but for interwiki transclusion it sometimes does.
 977                         // Use the canonical namespaces if possible to try to
 978                         // resolve a foreign namespace.
 979                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 980                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 981                         }
 982                 }
 983
 984                 try {
 985                         $formatter = self::getTitleFormatter();
 986                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 987                 } catch ( InvalidArgumentException $ex ) {
 988                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 989                         return false;
 990                 }
 991         }
 992
 993         /**
 994          * Get the namespace text of the subject (rather than talk) page
 995          *
 996          * @return string Namespace text
 997          */
 998         public function getSubjectNsText() {
 999                 global $wgContLang;
1000                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1001         }
1002
1003         /**
1004          * Get the namespace text of the talk page
1005          *
1006          * @return string Namespace text
1007          */
1008         public function getTalkNsText() {
1009                 global $wgContLang;
1010                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1011         }
1012
1013         /**
1014          * Could this title have a corresponding talk page?
1015          *
1016          * @return bool
1017          */
1018         public function canTalk() {
1019                 return MWNamespace::canTalk( $this->mNamespace );
1020         }
1021
1022         /**
1023          * Is this in a namespace that allows actual pages?
1024          *
1025          * @return bool
1026          */
1027         public function canExist() {
1028                 return $this->mNamespace >= NS_MAIN;
1029         }
1030
1031         /**
1032          * Can this title be added to a user's watchlist?
1033          *
1034          * @return bool
1035          */
1036         public function isWatchable() {
1037                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1038         }
1039
1040         /**
1041          * Returns true if this is a special page.
1042          *
1043          * @return bool
1044          */
1045         public function isSpecialPage() {
1046                 return $this->getNamespace() == NS_SPECIAL;
1047         }
1048
1049         /**
1050          * Returns true if this title resolves to the named special page
1051          *
1052          * @param string $name The special page name
1053          * @return bool
1054          */
1055         public function isSpecial( $name ) {
1056                 if ( $this->isSpecialPage() ) {
1057                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1058                         if ( $name == $thisName ) {
1059                                 return true;
1060                         }
1061                 }
1062                 return false;
1063         }
1064
1065         /**
1066          * If the Title refers to a special page alias which is not the local default, resolve
1067          * the alias, and localise the name as necessary.  Otherwise, return $this
1068          *
1069          * @return Title
1070          */
1071         public function fixSpecialName() {
1072                 if ( $this->isSpecialPage() ) {
1073                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1074                         if ( $canonicalName ) {
1075                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1076                                 if ( $localName != $this->mDbkeyform ) {
1077                                         return Title::makeTitle( NS_SPECIAL, $localName );
1078                                 }
1079                         }
1080                 }
1081                 return $this;
1082         }
1083
1084         /**
1085          * Returns true if the title is inside the specified namespace.
1086          *
1087          * Please make use of this instead of comparing to getNamespace()
1088          * This function is much more resistant to changes we may make
1089          * to namespaces than code that makes direct comparisons.
1090          * @param int $ns The namespace
1091          * @return bool
1092          * @since 1.19
1093          */
1094         public function inNamespace( $ns ) {
1095                 return MWNamespace::equals( $this->getNamespace(), $ns );
1096         }
1097
1098         /**
1099          * Returns true if the title is inside one of the specified namespaces.
1100          *
1101          * @param int $namespaces,... The namespaces to check for
1102          * @return bool
1103          * @since 1.19
1104          */
1105         public function inNamespaces( /* ... */ ) {
1106                 $namespaces = func_get_args();
1107                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1108                         $namespaces = $namespaces[0];
1109                 }
1110
1111                 foreach ( $namespaces as $ns ) {
1112                         if ( $this->inNamespace( $ns ) ) {
1113                                 return true;
1114                         }
1115                 }
1116
1117                 return false;
1118         }
1119
1120         /**
1121          * Returns true if the title has the same subject namespace as the
1122          * namespace specified.
1123          * For example this method will take NS_USER and return true if namespace
1124          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1125          * as their subject namespace.
1126          *
1127          * This is MUCH simpler than individually testing for equivalence
1128          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1129          * @since 1.19
1130          * @param int $ns
1131          * @return bool
1132          */
1133         public function hasSubjectNamespace( $ns ) {
1134                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1135         }
1136
1137         /**
1138          * Is this Title in a namespace which contains content?
1139          * In other words, is this a content page, for the purposes of calculating
1140          * statistics, etc?
1141          *
1142          * @return bool
1143          */
1144         public function isContentPage() {
1145                 return MWNamespace::isContent( $this->getNamespace() );
1146         }
1147
1148         /**
1149          * Would anybody with sufficient privileges be able to move this page?
1150          * Some pages just aren't movable.
1151          *
1152          * @return bool
1153          */
1154         public function isMovable() {
1155                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1156                         // Interwiki title or immovable namespace. Hooks don't get to override here
1157                         return false;
1158                 }
1159
1160                 $result = true;
1161                 Hooks::run( 'TitleIsMovable', [ $this, &$result ] );
1162                 return $result;
1163         }
1164
1165         /**
1166          * Is this the mainpage?
1167          * @note Title::newFromText seems to be sufficiently optimized by the title
1168          * cache that we don't need to over-optimize by doing direct comparisons and
1169          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1170          * ends up reporting something differently than $title->isMainPage();
1171          *
1172          * @since 1.18
1173          * @return bool
1174          */
1175         public function isMainPage() {
1176                 return $this->equals( Title::newMainPage() );
1177         }
1178
1179         /**
1180          * Is this a subpage?
1181          *
1182          * @return bool
1183          */
1184         public function isSubpage() {
1185                 return MWNamespace::hasSubpages( $this->mNamespace )
1186                         ? strpos( $this->getText(), '/' ) !== false
1187                         : false;
1188         }
1189
1190         /**
1191          * Is this a conversion table for the LanguageConverter?
1192          *
1193          * @return bool
1194          */
1195         public function isConversionTable() {
1196                 // @todo ConversionTable should become a separate content model.
1197
1198                 return $this->getNamespace() == NS_MEDIAWIKI &&
1199                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1200         }
1201
1202         /**
1203          * Does that page contain wikitext, or it is JS, CSS or whatever?
1204          *
1205          * @return bool
1206          */
1207         public function isWikitextPage() {
1208                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1209         }
1210
1211         /**
1212          * Could this page contain custom CSS or JavaScript for the global UI.
1213          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1214          * or CONTENT_MODEL_JAVASCRIPT.
1215          *
1216          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1217          * for that!
1218          *
1219          * Note that this method should not return true for pages that contain and
1220          * show "inactive" CSS or JS.
1221          *
1222          * @return bool
1223          * @todo FIXME: Rename to isSiteConfigPage() and remove deprecated hook
1224          */
1225         public function isCssOrJsPage() {
1226                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1227                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1228                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1229
1230                 # @note This hook is also called in ContentHandler::getDefaultModel.
1231                 #   It's called here again to make sure hook functions can force this
1232                 #   method to return true even outside the MediaWiki namespace.
1233
1234                 Hooks::run( 'TitleIsCssOrJsPage', [ $this, &$isCssOrJsPage ], '1.25' );
1235
1236                 return $isCssOrJsPage;
1237         }
1238
1239         /**
1240          * Is this a .css or .js subpage of a user page?
1241          * @return bool
1242          * @todo FIXME: Rename to isUserConfigPage()
1243          */
1244         public function isCssJsSubpage() {
1245                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1246                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1247                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1248         }
1249
1250         /**
1251          * Trim down a .css or .js subpage title to get the corresponding skin name
1252          *
1253          * @return string Containing skin name from .css or .js subpage title
1254          */
1255         public function getSkinFromCssJsSubpage() {
1256                 $subpage = explode( '/', $this->mTextform );
1257                 $subpage = $subpage[count( $subpage ) - 1];
1258                 $lastdot = strrpos( $subpage, '.' );
1259                 if ( $lastdot === false ) {
1260                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1261                 }
1262                 return substr( $subpage, 0, $lastdot );
1263         }
1264
1265         /**
1266          * Is this a .css subpage of a user page?
1267          *
1268          * @return bool
1269          */
1270         public function isCssSubpage() {
1271                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1272                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1273         }
1274
1275         /**
1276          * Is this a .js subpage of a user page?
1277          *
1278          * @return bool
1279          */
1280         public function isJsSubpage() {
1281                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1282                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1283         }
1284
1285         /**
1286          * Is this a talk page of some sort?
1287          *
1288          * @return bool
1289          */
1290         public function isTalkPage() {
1291                 return MWNamespace::isTalk( $this->getNamespace() );
1292         }
1293
1294         /**
1295          * Get a Title object associated with the talk page of this article
1296          *
1297          * @return Title The object for the talk page
1298          */
1299         public function getTalkPage() {
1300                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1301         }
1302
1303         /**
1304          * Get a title object associated with the subject page of this
1305          * talk page
1306          *
1307          * @return Title The object for the subject page
1308          */
1309         public function getSubjectPage() {
1310                 // Is this the same title?
1311                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1312                 if ( $this->getNamespace() == $subjectNS ) {
1313                         return $this;
1314                 }
1315                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1316         }
1317
1318         /**
1319          * Get the other title for this page, if this is a subject page
1320          * get the talk page, if it is a subject page get the talk page
1321          *
1322          * @since 1.25
1323          * @throws MWException
1324          * @return Title
1325          */
1326         public function getOtherPage() {
1327                 if ( $this->isSpecialPage() ) {
1328                         throw new MWException( 'Special pages cannot have other pages' );
1329                 }
1330                 if ( $this->isTalkPage() ) {
1331                         return $this->getSubjectPage();
1332                 } else {
1333                         return $this->getTalkPage();
1334                 }
1335         }
1336
1337         /**
1338          * Get the default namespace index, for when there is no namespace
1339          *
1340          * @return int Default namespace index
1341          */
1342         public function getDefaultNamespace() {
1343                 return $this->mDefaultNamespace;
1344         }
1345
1346         /**
1347          * Get the Title fragment (i.e.\ the bit after the #) in text form
1348          *
1349          * Use Title::hasFragment to check for a fragment
1350          *
1351          * @return string Title fragment
1352          */
1353         public function getFragment() {
1354                 return $this->mFragment;
1355         }
1356
1357         /**
1358          * Check if a Title fragment is set
1359          *
1360          * @return bool
1361          * @since 1.23
1362          */
1363         public function hasFragment() {
1364                 return $this->mFragment !== '';
1365         }
1366
1367         /**
1368          * Get the fragment in URL form, including the "#" character if there is one
1369          * @return string Fragment in URL form
1370          */
1371         public function getFragmentForURL() {
1372                 if ( !$this->hasFragment() ) {
1373                         return '';
1374                 } else {
1375                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1376                 }
1377         }
1378
1379         /**
1380          * Set the fragment for this title. Removes the first character from the
1381          * specified fragment before setting, so it assumes you're passing it with
1382          * an initial "#".
1383          *
1384          * Deprecated for public use, use Title::makeTitle() with fragment parameter,
1385          * or Title::createFragmentTarget().
1386          * Still in active use privately.
1387          *
1388          * @private
1389          * @param string $fragment Text
1390          */
1391         public function setFragment( $fragment ) {
1392                 $this->mFragment = strtr( substr( $fragment, 1 ), '_', ' ' );
1393         }
1394
1395         /**
1396          * Creates a new Title for a different fragment of the same page.
1397          *
1398          * @since 1.27
1399          * @param string $fragment
1400          * @return Title
1401          */
1402         public function createFragmentTarget( $fragment ) {
1403                 return self::makeTitle(
1404                         $this->getNamespace(),
1405                         $this->getText(),
1406                         $fragment,
1407                         $this->getInterwiki()
1408                 );
1409
1410         }
1411
1412         /**
1413          * Prefix some arbitrary text with the namespace or interwiki prefix
1414          * of this object
1415          *
1416          * @param string $name The text
1417          * @return string The prefixed text
1418          */
1419         private function prefix( $name ) {
1420                 $p = '';
1421                 if ( $this->isExternal() ) {
1422                         $p = $this->mInterwiki . ':';
1423                 }
1424
1425                 if ( 0 != $this->mNamespace ) {
1426                         $p .= $this->getNsText() . ':';
1427                 }
1428                 return $p . $name;
1429         }
1430
1431         /**
1432          * Get the prefixed database key form
1433          *
1434          * @return string The prefixed title, with underscores and
1435          *  any interwiki and namespace prefixes
1436          */
1437         public function getPrefixedDBkey() {
1438                 $s = $this->prefix( $this->mDbkeyform );
1439                 $s = strtr( $s, ' ', '_' );
1440                 return $s;
1441         }
1442
1443         /**
1444          * Get the prefixed title with spaces.
1445          * This is the form usually used for display
1446          *
1447          * @return string The prefixed title, with spaces
1448          */
1449         public function getPrefixedText() {
1450                 if ( $this->mPrefixedText === null ) {
1451                         $s = $this->prefix( $this->mTextform );
1452                         $s = strtr( $s, '_', ' ' );
1453                         $this->mPrefixedText = $s;
1454                 }
1455                 return $this->mPrefixedText;
1456         }
1457
1458         /**
1459          * Return a string representation of this title
1460          *
1461          * @return string Representation of this title
1462          */
1463         public function __toString() {
1464                 return $this->getPrefixedText();
1465         }
1466
1467         /**
1468          * Get the prefixed title with spaces, plus any fragment
1469          * (part beginning with '#')
1470          *
1471          * @return string The prefixed title, with spaces and the fragment, including '#'
1472          */
1473         public function getFullText() {
1474                 $text = $this->getPrefixedText();
1475                 if ( $this->hasFragment() ) {
1476                         $text .= '#' . $this->getFragment();
1477                 }
1478                 return $text;
1479         }
1480
1481         /**
1482          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1483          *
1484          * @par Example:
1485          * @code
1486          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1487          * # returns: 'Foo'
1488          * @endcode
1489          *
1490          * @return string Root name
1491          * @since 1.20
1492          */
1493         public function getRootText() {
1494                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1495                         return $this->getText();
1496                 }
1497
1498                 return strtok( $this->getText(), '/' );
1499         }
1500
1501         /**
1502          * Get the root page name title, i.e. the leftmost part before any slashes
1503          *
1504          * @par Example:
1505          * @code
1506          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1507          * # returns: Title{User:Foo}
1508          * @endcode
1509          *
1510          * @return Title Root title
1511          * @since 1.20
1512          */
1513         public function getRootTitle() {
1514                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1515         }
1516
1517         /**
1518          * Get the base page name without a namespace, i.e. the part before the subpage name
1519          *
1520          * @par Example:
1521          * @code
1522          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1523          * # returns: 'Foo/Bar'
1524          * @endcode
1525          *
1526          * @return string Base name
1527          */
1528         public function getBaseText() {
1529                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1530                         return $this->getText();
1531                 }
1532
1533                 $parts = explode( '/', $this->getText() );
1534                 # Don't discard the real title if there's no subpage involved
1535                 if ( count( $parts ) > 1 ) {
1536                         unset( $parts[count( $parts ) - 1] );
1537                 }
1538                 return implode( '/', $parts );
1539         }
1540
1541         /**
1542          * Get the base page name title, i.e. the part before the subpage name
1543          *
1544          * @par Example:
1545          * @code
1546          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1547          * # returns: Title{User:Foo/Bar}
1548          * @endcode
1549          *
1550          * @return Title Base title
1551          * @since 1.20
1552          */
1553         public function getBaseTitle() {
1554                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1555         }
1556
1557         /**
1558          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1559          *
1560          * @par Example:
1561          * @code
1562          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1563          * # returns: "Baz"
1564          * @endcode
1565          *
1566          * @return string Subpage name
1567          */
1568         public function getSubpageText() {
1569                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1570                         return $this->mTextform;
1571                 }
1572                 $parts = explode( '/', $this->mTextform );
1573                 return $parts[count( $parts ) - 1];
1574         }
1575
1576         /**
1577          * Get the title for a subpage of the current page
1578          *
1579          * @par Example:
1580          * @code
1581          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1582          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1583          * @endcode
1584          *
1585          * @param string $text The subpage name to add to the title
1586          * @return Title Subpage title
1587          * @since 1.20
1588          */
1589         public function getSubpage( $text ) {
1590                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1591         }
1592
1593         /**
1594          * Get a URL-encoded form of the subpage text
1595          *
1596          * @return string URL-encoded subpage name
1597          */
1598         public function getSubpageUrlForm() {
1599                 $text = $this->getSubpageText();
1600                 $text = wfUrlencode( strtr( $text, ' ', '_' ) );
1601                 return $text;
1602         }
1603
1604         /**
1605          * Get a URL-encoded title (not an actual URL) including interwiki
1606          *
1607          * @return string The URL-encoded form
1608          */
1609         public function getPrefixedURL() {
1610                 $s = $this->prefix( $this->mDbkeyform );
1611                 $s = wfUrlencode( strtr( $s, ' ', '_' ) );
1612                 return $s;
1613         }
1614
1615         /**
1616          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1617          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1618          * second argument named variant. This was deprecated in favor
1619          * of passing an array of option with a "variant" key
1620          * Once $query2 is removed for good, this helper can be dropped
1621          * and the wfArrayToCgi moved to getLocalURL();
1622          *
1623          * @since 1.19 (r105919)
1624          * @param array|string $query
1625          * @param bool $query2
1626          * @return string
1627          */
1628         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1629                 if ( $query2 !== false ) {
1630                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1631                                 "method called with a second parameter is deprecated. Add your " .
1632                                 "parameter to an array passed as the first parameter.", "1.19" );
1633                 }
1634                 if ( is_array( $query ) ) {
1635                         $query = wfArrayToCgi( $query );
1636                 }
1637                 if ( $query2 ) {
1638                         if ( is_string( $query2 ) ) {
1639                                 // $query2 is a string, we will consider this to be
1640                                 // a deprecated $variant argument and add it to the query
1641                                 $query2 = wfArrayToCgi( [ 'variant' => $query2 ] );
1642                         } else {
1643                                 $query2 = wfArrayToCgi( $query2 );
1644                         }
1645                         // If we have $query content add a & to it first
1646                         if ( $query ) {
1647                                 $query .= '&';
1648                         }
1649                         // Now append the queries together
1650                         $query .= $query2;
1651                 }
1652                 return $query;
1653         }
1654
1655         /**
1656          * Get a real URL referring to this title, with interwiki link and
1657          * fragment
1658          *
1659          * @see self::getLocalURL for the arguments.
1660          * @see wfExpandUrl
1661          * @param array|string $query
1662          * @param bool $query2
1663          * @param string $proto Protocol type to use in URL
1664          * @return string The URL
1665          */
1666         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1667                 $query = self::fixUrlQueryArgs( $query, $query2 );
1668
1669                 # Hand off all the decisions on urls to getLocalURL
1670                 $url = $this->getLocalURL( $query );
1671
1672                 # Expand the url to make it a full url. Note that getLocalURL has the
1673                 # potential to output full urls for a variety of reasons, so we use
1674                 # wfExpandUrl instead of simply prepending $wgServer
1675                 $url = wfExpandUrl( $url, $proto );
1676
1677                 # Finally, add the fragment.
1678                 $url .= $this->getFragmentForURL();
1679
1680                 Hooks::run( 'GetFullURL', [ &$this, &$url, $query ] );
1681                 return $url;
1682         }
1683
1684         /**
1685          * Get a URL with no fragment or server name (relative URL) from a Title object.
1686          * If this page is generated with action=render, however,
1687          * $wgServer is prepended to make an absolute URL.
1688          *
1689          * @see self::getFullURL to always get an absolute URL.
1690          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1691          *  valid to link, locally, to the current Title.
1692          * @see self::newFromText to produce a Title object.
1693          *
1694          * @param string|array $query An optional query string,
1695          *   not used for interwiki links. Can be specified as an associative array as well,
1696          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1697          *   Some query patterns will trigger various shorturl path replacements.
1698          * @param array $query2 An optional secondary query array. This one MUST
1699          *   be an array. If a string is passed it will be interpreted as a deprecated
1700          *   variant argument and urlencoded into a variant= argument.
1701          *   This second query argument will be added to the $query
1702          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1703          *   pair in the first parameter array instead.
1704          *
1705          * @return string String of the URL.
1706          */
1707         public function getLocalURL( $query = '', $query2 = false ) {
1708                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1709
1710                 $query = self::fixUrlQueryArgs( $query, $query2 );
1711
1712                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1713                 if ( $interwiki ) {
1714                         $namespace = $this->getNsText();
1715                         if ( $namespace != '' ) {
1716                                 # Can this actually happen? Interwikis shouldn't be parsed.
1717                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1718                                 $namespace .= ':';
1719                         }
1720                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1721                         $url = wfAppendQuery( $url, $query );
1722                 } else {
1723                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1724                         if ( $query == '' ) {
1725                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1726                                 Hooks::run( 'GetLocalURL::Article', [ &$this, &$url ] );
1727                         } else {
1728                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1729                                 $url = false;
1730                                 $matches = [];
1731
1732                                 if ( !empty( $wgActionPaths )
1733                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1734                                 ) {
1735                                         $action = urldecode( $matches[2] );
1736                                         if ( isset( $wgActionPaths[$action] ) ) {
1737                                                 $query = $matches[1];
1738                                                 if ( isset( $matches[4] ) ) {
1739                                                         $query .= $matches[4];
1740                                                 }
1741                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1742                                                 if ( $query != '' ) {
1743                                                         $url = wfAppendQuery( $url, $query );
1744                                                 }
1745                                         }
1746                                 }
1747
1748                                 if ( $url === false
1749                                         && $wgVariantArticlePath
1750                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1751                                         && $this->getPageLanguage()->hasVariants()
1752                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1753                                 ) {
1754                                         $variant = urldecode( $matches[1] );
1755                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1756                                                 // Only do the variant replacement if the given variant is a valid
1757                                                 // variant for the page's language.
1758                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1759                                                 $url = str_replace( '$1', $dbkey, $url );
1760                                         }
1761                                 }
1762
1763                                 if ( $url === false ) {
1764                                         if ( $query == '-' ) {
1765                                                 $query = '';
1766                                         }
1767                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1768                                 }
1769                         }
1770
1771                         Hooks::run( 'GetLocalURL::Internal', [ &$this, &$url, $query ] );
1772
1773                         // @todo FIXME: This causes breakage in various places when we
1774                         // actually expected a local URL and end up with dupe prefixes.
1775                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1776                                 $url = $wgServer . $url;
1777                         }
1778                 }
1779                 Hooks::run( 'GetLocalURL', [ &$this, &$url, $query ] );
1780                 return $url;
1781         }
1782
1783         /**
1784          * Get a URL that's the simplest URL that will be valid to link, locally,
1785          * to the current Title.  It includes the fragment, but does not include
1786          * the server unless action=render is used (or the link is external).  If
1787          * there's a fragment but the prefixed text is empty, we just return a link
1788          * to the fragment.
1789          *
1790          * The result obviously should not be URL-escaped, but does need to be
1791          * HTML-escaped if it's being output in HTML.
1792          *
1793          * @param array $query
1794          * @param bool $query2
1795          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1796          * @see self::getLocalURL for the arguments.
1797          * @return string The URL
1798          */
1799         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1800                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1801                         $ret = $this->getFullURL( $query, $query2, $proto );
1802                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1803                         $ret = $this->getFragmentForURL();
1804                 } else {
1805                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1806                 }
1807                 return $ret;
1808         }
1809
1810         /**
1811          * Get the URL form for an internal link.
1812          * - Used in various CDN-related code, in case we have a different
1813          * internal hostname for the server from the exposed one.
1814          *
1815          * This uses $wgInternalServer to qualify the path, or $wgServer
1816          * if $wgInternalServer is not set. If the server variable used is
1817          * protocol-relative, the URL will be expanded to http://
1818          *
1819          * @see self::getLocalURL for the arguments.
1820          * @return string The URL
1821          */
1822         public function getInternalURL( $query = '', $query2 = false ) {
1823                 global $wgInternalServer, $wgServer;
1824                 $query = self::fixUrlQueryArgs( $query, $query2 );
1825                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1826                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1827                 Hooks::run( 'GetInternalURL', [ &$this, &$url, $query ] );
1828                 return $url;
1829         }
1830
1831         /**
1832          * Get the URL for a canonical link, for use in things like IRC and
1833          * e-mail notifications. Uses $wgCanonicalServer and the
1834          * GetCanonicalURL hook.
1835          *
1836          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1837          *
1838          * @see self::getLocalURL for the arguments.
1839          * @return string The URL
1840          * @since 1.18
1841          */
1842         public function getCanonicalURL( $query = '', $query2 = false ) {
1843                 $query = self::fixUrlQueryArgs( $query, $query2 );
1844                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1845                 Hooks::run( 'GetCanonicalURL', [ &$this, &$url, $query ] );
1846                 return $url;
1847         }
1848
1849         /**
1850          * Get the edit URL for this Title
1851          *
1852          * @return string The URL, or a null string if this is an interwiki link
1853          */
1854         public function getEditURL() {
1855                 if ( $this->isExternal() ) {
1856                         return '';
1857                 }
1858                 $s = $this->getLocalURL( 'action=edit' );
1859
1860                 return $s;
1861         }
1862
1863         /**
1864          * Can $user perform $action on this page?
1865          * This skips potentially expensive cascading permission checks
1866          * as well as avoids expensive error formatting
1867          *
1868          * Suitable for use for nonessential UI controls in common cases, but
1869          * _not_ for functional access control.
1870          *
1871          * May provide false positives, but should never provide a false negative.
1872          *
1873          * @param string $action Action that permission needs to be checked for
1874          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1875          * @return bool
1876          */
1877         public function quickUserCan( $action, $user = null ) {
1878                 return $this->userCan( $action, $user, false );
1879         }
1880
1881         /**
1882          * Can $user perform $action on this page?
1883          *
1884          * @param string $action Action that permission needs to be checked for
1885          * @param User $user User to check (since 1.19); $wgUser will be used if not
1886          *   provided.
1887          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1888          * @return bool
1889          */
1890         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1891                 if ( !$user instanceof User ) {
1892                         global $wgUser;
1893                         $user = $wgUser;
1894                 }
1895
1896                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1897         }
1898
1899         /**
1900          * Can $user perform $action on this page?
1901          *
1902          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1903          *
1904          * @param string $action Action that permission needs to be checked for
1905          * @param User $user User to check
1906          * @param string $rigor One of (quick,full,secure)
1907          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
1908          *   - full   : does cheap and expensive checks possibly from a slave
1909          *   - secure : does cheap and expensive checks, using the master as needed
1910          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1911          *   whose corresponding errors may be ignored.
1912          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
1913          */
1914         public function getUserPermissionsErrors(
1915                 $action, $user, $rigor = 'secure', $ignoreErrors = []
1916         ) {
1917                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1918
1919                 // Remove the errors being ignored.
1920                 foreach ( $errors as $index => $error ) {
1921                         $errKey = is_array( $error ) ? $error[0] : $error;
1922
1923                         if ( in_array( $errKey, $ignoreErrors ) ) {
1924                                 unset( $errors[$index] );
1925                         }
1926                         if ( $errKey instanceof MessageSpecifier && in_array( $errKey->getKey(), $ignoreErrors ) ) {
1927                                 unset( $errors[$index] );
1928                         }
1929                 }
1930
1931                 return $errors;
1932         }
1933
1934         /**
1935          * Permissions checks that fail most often, and which are easiest to test.
1936          *
1937          * @param string $action The action to check
1938          * @param User $user User to check
1939          * @param array $errors List of current errors
1940          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1941          * @param bool $short Short circuit on first error
1942          *
1943          * @return array List of errors
1944          */
1945         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1946                 if ( !Hooks::run( 'TitleQuickPermissions',
1947                         [ $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ] )
1948                 ) {
1949                         return $errors;
1950                 }
1951
1952                 if ( $action == 'create' ) {
1953                         if (
1954                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1955                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1956                         ) {
1957                                 $errors[] = $user->isAnon() ? [ 'nocreatetext' ] : [ 'nocreate-loggedin' ];
1958                         }
1959                 } elseif ( $action == 'move' ) {
1960                         if ( !$user->isAllowed( 'move-rootuserpages' )
1961                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1962                                 // Show user page-specific message only if the user can move other pages
1963                                 $errors[] = [ 'cant-move-user-page' ];
1964                         }
1965
1966                         // Check if user is allowed to move files if it's a file
1967                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1968                                 $errors[] = [ 'movenotallowedfile' ];
1969                         }
1970
1971                         // Check if user is allowed to move category pages if it's a category page
1972                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1973                                 $errors[] = [ 'cant-move-category-page' ];
1974                         }
1975
1976                         if ( !$user->isAllowed( 'move' ) ) {
1977                                 // User can't move anything
1978                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1979                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1980                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1981                                         // custom message if logged-in users without any special rights can move
1982                                         $errors[] = [ 'movenologintext' ];
1983                                 } else {
1984                                         $errors[] = [ 'movenotallowed' ];
1985                                 }
1986                         }
1987                 } elseif ( $action == 'move-target' ) {
1988                         if ( !$user->isAllowed( 'move' ) ) {
1989                                 // User can't move anything
1990                                 $errors[] = [ 'movenotallowed' ];
1991                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1992                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1993                                 // Show user page-specific message only if the user can move other pages
1994                                 $errors[] = [ 'cant-move-to-user-page' ];
1995                         } elseif ( !$user->isAllowed( 'move-categorypages' )
1996                                         && $this->mNamespace == NS_CATEGORY ) {
1997                                 // Show category page-specific message only if the user can move other pages
1998                                 $errors[] = [ 'cant-move-to-category-page' ];
1999                         }
2000                 } elseif ( !$user->isAllowed( $action ) ) {
2001                         $errors[] = $this->missingPermissionError( $action, $short );
2002                 }
2003
2004                 return $errors;
2005         }
2006
2007         /**
2008          * Add the resulting error code to the errors array
2009          *
2010          * @param array $errors List of current errors
2011          * @param array $result Result of errors
2012          *
2013          * @return array List of errors
2014          */
2015         private function resultToError( $errors, $result ) {
2016                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2017                         // A single array representing an error
2018                         $errors[] = $result;
2019                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2020                         // A nested array representing multiple errors
2021                         $errors = array_merge( $errors, $result );
2022                 } elseif ( $result !== '' && is_string( $result ) ) {
2023                         // A string representing a message-id
2024                         $errors[] = [ $result ];
2025                 } elseif ( $result instanceof MessageSpecifier ) {
2026                         // A message specifier representing an error
2027                         $errors[] = [ $result ];
2028                 } elseif ( $result === false ) {
2029                         // a generic "We don't want them to do that"
2030                         $errors[] = [ 'badaccess-group0' ];
2031                 }
2032                 return $errors;
2033         }
2034
2035         /**
2036          * Check various permission hooks
2037          *
2038          * @param string $action The action to check
2039          * @param User $user User to check
2040          * @param array $errors List of current errors
2041          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2042          * @param bool $short Short circuit on first error
2043          *
2044          * @return array List of errors
2045          */
2046         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2047                 // Use getUserPermissionsErrors instead
2048                 $result = '';
2049                 if ( !Hooks::run( 'userCan', [ &$this, &$user, $action, &$result ] ) ) {
2050                         return $result ? [] : [ [ 'badaccess-group0' ] ];
2051                 }
2052                 // Check getUserPermissionsErrors hook
2053                 if ( !Hooks::run( 'getUserPermissionsErrors', [ &$this, &$user, $action, &$result ] ) ) {
2054                         $errors = $this->resultToError( $errors, $result );
2055                 }
2056                 // Check getUserPermissionsErrorsExpensive hook
2057                 if (
2058                         $rigor !== 'quick'
2059                         && !( $short && count( $errors ) > 0 )
2060                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', [ &$this, &$user, $action, &$result ] )
2061                 ) {
2062                         $errors = $this->resultToError( $errors, $result );
2063                 }
2064
2065                 return $errors;
2066         }
2067
2068         /**
2069          * Check permissions on special pages & namespaces
2070          *
2071          * @param string $action The action to check
2072          * @param User $user User to check
2073          * @param array $errors List of current errors
2074          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2075          * @param bool $short Short circuit on first error
2076          *
2077          * @return array List of errors
2078          */
2079         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2080                 # Only 'createaccount' can be performed on special pages,
2081                 # which don't actually exist in the DB.
2082                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2083                         $errors[] = [ 'ns-specialprotected' ];
2084                 }
2085
2086                 # Check $wgNamespaceProtection for restricted namespaces
2087                 if ( $this->isNamespaceProtected( $user ) ) {
2088                         $ns = $this->mNamespace == NS_MAIN ?
2089                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2090                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2091                                 [ 'protectedinterface', $action ] : [ 'namespaceprotected', $ns, $action ];
2092                 }
2093
2094                 return $errors;
2095         }
2096
2097         /**
2098          * Check CSS/JS sub-page permissions
2099          *
2100          * @param string $action The action to check
2101          * @param User $user User to check
2102          * @param array $errors List of current errors
2103          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2104          * @param bool $short Short circuit on first error
2105          *
2106          * @return array List of errors
2107          */
2108         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2109                 # Protect css/js subpages of user pages
2110                 # XXX: this might be better using restrictions
2111                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2112                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2113                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2114                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2115                                         $errors[] = [ 'mycustomcssprotected', $action ];
2116                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2117                                         $errors[] = [ 'mycustomjsprotected', $action ];
2118                                 }
2119                         } else {
2120                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2121                                         $errors[] = [ 'customcssprotected', $action ];
2122                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2123                                         $errors[] = [ 'customjsprotected', $action ];
2124                                 }
2125                         }
2126                 }
2127
2128                 return $errors;
2129         }
2130
2131         /**
2132          * Check against page_restrictions table requirements on this
2133          * page. The user must possess all required rights for this
2134          * action.
2135          *
2136          * @param string $action The action to check
2137          * @param User $user User to check
2138          * @param array $errors List of current errors
2139          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2140          * @param bool $short Short circuit on first error
2141          *
2142          * @return array List of errors
2143          */
2144         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2145                 foreach ( $this->getRestrictions( $action ) as $right ) {
2146                         // Backwards compatibility, rewrite sysop -> editprotected
2147                         if ( $right == 'sysop' ) {
2148                                 $right = 'editprotected';
2149                         }
2150                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2151                         if ( $right == 'autoconfirmed' ) {
2152                                 $right = 'editsemiprotected';
2153                         }
2154                         if ( $right == '' ) {
2155                                 continue;
2156                         }
2157                         if ( !$user->isAllowed( $right ) ) {
2158                                 $errors[] = [ 'protectedpagetext', $right, $action ];
2159                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2160                                 $errors[] = [ 'protectedpagetext', 'protect', $action ];
2161                         }
2162                 }
2163
2164                 return $errors;
2165         }
2166
2167         /**
2168          * Check restrictions on cascading pages.
2169          *
2170          * @param string $action The action to check
2171          * @param User $user User to check
2172          * @param array $errors List of current errors
2173          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2174          * @param bool $short Short circuit on first error
2175          *
2176          * @return array List of errors
2177          */
2178         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2179                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2180                         # We /could/ use the protection level on the source page, but it's
2181                         # fairly ugly as we have to establish a precedence hierarchy for pages
2182                         # included by multiple cascade-protected pages. So just restrict
2183                         # it to people with 'protect' permission, as they could remove the
2184                         # protection anyway.
2185                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2186                         # Cascading protection depends on more than this page...
2187                         # Several cascading protected pages may include this page...
2188                         # Check each cascading level
2189                         # This is only for protection restrictions, not for all actions
2190                         if ( isset( $restrictions[$action] ) ) {
2191                                 foreach ( $restrictions[$action] as $right ) {
2192                                         // Backwards compatibility, rewrite sysop -> editprotected
2193                                         if ( $right == 'sysop' ) {
2194                                                 $right = 'editprotected';
2195                                         }
2196                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2197                                         if ( $right == 'autoconfirmed' ) {
2198                                                 $right = 'editsemiprotected';
2199                                         }
2200                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2201                                                 $pages = '';
2202                                                 foreach ( $cascadingSources as $page ) {
2203                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2204                                                 }
2205                                                 $errors[] = [ 'cascadeprotected', count( $cascadingSources ), $pages, $action ];
2206                                         }
2207                                 }
2208                         }
2209                 }
2210
2211                 return $errors;
2212         }
2213
2214         /**
2215          * Check action permissions not already checked in checkQuickPermissions
2216          *
2217          * @param string $action The action to check
2218          * @param User $user User to check
2219          * @param array $errors List of current errors
2220          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2221          * @param bool $short Short circuit on first error
2222          *
2223          * @return array List of errors
2224          */
2225         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2226                 global $wgDeleteRevisionsLimit, $wgLang;
2227
2228                 if ( $action == 'protect' ) {
2229                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2230                                 // If they can't edit, they shouldn't protect.
2231                                 $errors[] = [ 'protect-cantedit' ];
2232                         }
2233                 } elseif ( $action == 'create' ) {
2234                         $title_protection = $this->getTitleProtection();
2235                         if ( $title_protection ) {
2236                                 if ( $title_protection['permission'] == ''
2237                                         || !$user->isAllowed( $title_protection['permission'] )
2238                                 ) {
2239                                         $errors[] = [
2240                                                 'titleprotected',
2241                                                 User::whoIs( $title_protection['user'] ),
2242                                                 $title_protection['reason']
2243                                         ];
2244                                 }
2245                         }
2246                 } elseif ( $action == 'move' ) {
2247                         // Check for immobile pages
2248                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2249                                 // Specific message for this case
2250                                 $errors[] = [ 'immobile-source-namespace', $this->getNsText() ];
2251                         } elseif ( !$this->isMovable() ) {
2252                                 // Less specific message for rarer cases
2253                                 $errors[] = [ 'immobile-source-page' ];
2254                         }
2255                 } elseif ( $action == 'move-target' ) {
2256                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2257                                 $errors[] = [ 'immobile-target-namespace', $this->getNsText() ];
2258                         } elseif ( !$this->isMovable() ) {
2259                                 $errors[] = [ 'immobile-target-page' ];
2260                         }
2261                 } elseif ( $action == 'delete' ) {
2262                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, [], $rigor, true );
2263                         if ( !$tempErrors ) {
2264                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2265                                         $user, $tempErrors, $rigor, true );
2266                         }
2267                         if ( $tempErrors ) {
2268                                 // If protection keeps them from editing, they shouldn't be able to delete.
2269                                 $errors[] = [ 'deleteprotected' ];
2270                         }
2271                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2272                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2273                         ) {
2274                                 $errors[] = [ 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) ];
2275                         }
2276                 }
2277                 return $errors;
2278         }
2279
2280         /**
2281          * Check that the user isn't blocked from editing.
2282          *
2283          * @param string $action The action to check
2284          * @param User $user User to check
2285          * @param array $errors List of current errors
2286          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2287          * @param bool $short Short circuit on first error
2288          *
2289          * @return array List of errors
2290          */
2291         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2292                 // Account creation blocks handled at userlogin.
2293                 // Unblocking handled in SpecialUnblock
2294                 if ( $rigor === 'quick' || in_array( $action, [ 'createaccount', 'unblock' ] ) ) {
2295                         return $errors;
2296                 }
2297
2298                 global $wgEmailConfirmToEdit;
2299
2300                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2301                         $errors[] = [ 'confirmedittext' ];
2302                 }
2303
2304                 $useSlave = ( $rigor !== 'secure' );
2305                 if ( ( $action == 'edit' || $action == 'create' )
2306                         && !$user->isBlockedFrom( $this, $useSlave )
2307                 ) {
2308                         // Don't block the user from editing their own talk page unless they've been
2309                         // explicitly blocked from that too.
2310                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2311                         // @todo FIXME: Pass the relevant context into this function.
2312                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2313                 }
2314
2315                 return $errors;
2316         }
2317
2318         /**
2319          * Check that the user is allowed to read this page.
2320          *
2321          * @param string $action The action to check
2322          * @param User $user User to check
2323          * @param array $errors List of current errors
2324          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2325          * @param bool $short Short circuit on first error
2326          *
2327          * @return array List of errors
2328          */
2329         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2330                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2331
2332                 $whitelisted = false;
2333                 if ( User::isEveryoneAllowed( 'read' ) ) {
2334                         # Shortcut for public wikis, allows skipping quite a bit of code
2335                         $whitelisted = true;
2336                 } elseif ( $user->isAllowed( 'read' ) ) {
2337                         # If the user is allowed to read pages, he is allowed to read all pages
2338                         $whitelisted = true;
2339                 } elseif ( $this->isSpecial( 'Userlogin' )
2340                         || $this->isSpecial( 'ChangePassword' )
2341                         || $this->isSpecial( 'PasswordReset' )
2342                 ) {
2343                         # Always grant access to the login page.
2344                         # Even anons need to be able to log in.
2345                         $whitelisted = true;
2346                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2347                         # Time to check the whitelist
2348                         # Only do these checks is there's something to check against
2349                         $name = $this->getPrefixedText();
2350                         $dbName = $this->getPrefixedDBkey();
2351
2352                         // Check for explicit whitelisting with and without underscores
2353                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2354                                 $whitelisted = true;
2355                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2356                                 # Old settings might have the title prefixed with
2357                                 # a colon for main-namespace pages
2358                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2359                                         $whitelisted = true;
2360                                 }
2361                         } elseif ( $this->isSpecialPage() ) {
2362                                 # If it's a special page, ditch the subpage bit and check again
2363                                 $name = $this->getDBkey();
2364                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2365                                 if ( $name ) {
2366                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2367                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2368                                                 $whitelisted = true;
2369                                         }
2370                                 }
2371                         }
2372                 }
2373
2374                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2375                         $name = $this->getPrefixedText();
2376                         // Check for regex whitelisting
2377                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2378                                 if ( preg_match( $listItem, $name ) ) {
2379                                         $whitelisted = true;
2380                                         break;
2381                                 }
2382                         }
2383                 }
2384
2385                 if ( !$whitelisted ) {
2386                         # If the title is not whitelisted, give extensions a chance to do so...
2387                         Hooks::run( 'TitleReadWhitelist', [ $this, $user, &$whitelisted ] );
2388                         if ( !$whitelisted ) {
2389                                 $errors[] = $this->missingPermissionError( $action, $short );
2390                         }
2391                 }
2392
2393                 return $errors;
2394         }
2395
2396         /**
2397          * Get a description array when the user doesn't have the right to perform
2398          * $action (i.e. when User::isAllowed() returns false)
2399          *
2400          * @param string $action The action to check
2401          * @param bool $short Short circuit on first error
2402          * @return array List of errors
2403          */
2404         private function missingPermissionError( $action, $short ) {
2405                 // We avoid expensive display logic for quickUserCan's and such
2406                 if ( $short ) {
2407                         return [ 'badaccess-group0' ];
2408                 }
2409
2410                 $groups = array_map( [ 'User', 'makeGroupLinkWiki' ],
2411                         User::getGroupsWithPermission( $action ) );
2412
2413                 if ( count( $groups ) ) {
2414                         global $wgLang;
2415                         return [
2416                                 'badaccess-groups',
2417                                 $wgLang->commaList( $groups ),
2418                                 count( $groups )
2419                         ];
2420                 } else {
2421                         return [ 'badaccess-group0' ];
2422                 }
2423         }
2424
2425         /**
2426          * Can $user perform $action on this page? This is an internal function,
2427          * with multiple levels of checks depending on performance needs; see $rigor below.
2428          * It does not check wfReadOnly().
2429          *
2430          * @param string $action Action that permission needs to be checked for
2431          * @param User $user User to check
2432          * @param string $rigor One of (quick,full,secure)
2433          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
2434          *   - full   : does cheap and expensive checks possibly from a slave
2435          *   - secure : does cheap and expensive checks, using the master as needed
2436          * @param bool $short Set this to true to stop after the first permission error.
2437          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2438          */
2439         protected function getUserPermissionsErrorsInternal(
2440                 $action, $user, $rigor = 'secure', $short = false
2441         ) {
2442                 if ( $rigor === true ) {
2443                         $rigor = 'secure'; // b/c
2444                 } elseif ( $rigor === false ) {
2445                         $rigor = 'quick'; // b/c
2446                 } elseif ( !in_array( $rigor, [ 'quick', 'full', 'secure' ] ) ) {
2447                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2448                 }
2449
2450                 # Read has special handling
2451                 if ( $action == 'read' ) {
2452                         $checks = [
2453                                 'checkPermissionHooks',
2454                                 'checkReadPermissions',
2455                         ];
2456                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2457                 # here as it will lead to duplicate error messages. This is okay to do
2458                 # since anywhere that checks for create will also check for edit, and
2459                 # those checks are called for edit.
2460                 } elseif ( $action == 'create' ) {
2461                         $checks = [
2462                                 'checkQuickPermissions',
2463                                 'checkPermissionHooks',
2464                                 'checkPageRestrictions',
2465                                 'checkCascadingSourcesRestrictions',
2466                                 'checkActionPermissions',
2467                                 'checkUserBlock'
2468                         ];
2469                 } else {
2470                         $checks = [
2471                                 'checkQuickPermissions',
2472                                 'checkPermissionHooks',
2473                                 'checkSpecialsAndNSPermissions',
2474                                 'checkCSSandJSPermissions',
2475                                 'checkPageRestrictions',
2476                                 'checkCascadingSourcesRestrictions',
2477                                 'checkActionPermissions',
2478                                 'checkUserBlock'
2479                         ];
2480                 }
2481
2482                 $errors = [];
2483                 while ( count( $checks ) > 0 &&
2484                                 !( $short && count( $errors ) > 0 ) ) {
2485                         $method = array_shift( $checks );
2486                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2487                 }
2488
2489                 return $errors;
2490         }
2491
2492         /**
2493          * Get a filtered list of all restriction types supported by this wiki.
2494          * @param bool $exists True to get all restriction types that apply to
2495          * titles that do exist, False for all restriction types that apply to
2496          * titles that do not exist
2497          * @return array
2498          */
2499         public static function getFilteredRestrictionTypes( $exists = true ) {
2500                 global $wgRestrictionTypes;
2501                 $types = $wgRestrictionTypes;
2502                 if ( $exists ) {
2503                         # Remove the create restriction for existing titles
2504                         $types = array_diff( $types, [ 'create' ] );
2505                 } else {
2506                         # Only the create and upload restrictions apply to non-existing titles
2507                         $types = array_intersect( $types, [ 'create', 'upload' ] );
2508                 }
2509                 return $types;
2510         }
2511
2512         /**
2513          * Returns restriction types for the current Title
2514          *
2515          * @return array Applicable restriction types
2516          */
2517         public function getRestrictionTypes() {
2518                 if ( $this->isSpecialPage() ) {
2519                         return [];
2520                 }
2521
2522                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2523
2524                 if ( $this->getNamespace() != NS_FILE ) {
2525                         # Remove the upload restriction for non-file titles
2526                         $types = array_diff( $types, [ 'upload' ] );
2527                 }
2528
2529                 Hooks::run( 'TitleGetRestrictionTypes', [ $this, &$types ] );
2530
2531                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2532                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2533
2534                 return $types;
2535         }
2536
2537         /**
2538          * Is this title subject to title protection?
2539          * Title protection is the one applied against creation of such title.
2540          *
2541          * @return array|bool An associative array representing any existent title
2542          *   protection, or false if there's none.
2543          */
2544         public function getTitleProtection() {
2545                 // Can't protect pages in special namespaces
2546                 if ( $this->getNamespace() < 0 ) {
2547                         return false;
2548                 }
2549
2550                 // Can't protect pages that exist.
2551                 if ( $this->exists() ) {
2552                         return false;
2553                 }
2554
2555                 if ( $this->mTitleProtection === null ) {
2556                         $dbr = wfGetDB( DB_SLAVE );
2557                         $res = $dbr->select(
2558                                 'protected_titles',
2559                                 [
2560                                         'user' => 'pt_user',
2561                                         'reason' => 'pt_reason',
2562                                         'expiry' => 'pt_expiry',
2563                                         'permission' => 'pt_create_perm'
2564                                 ],
2565                                 [ 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ],
2566                                 __METHOD__
2567                         );
2568
2569                         // fetchRow returns false if there are no rows.
2570                         $row = $dbr->fetchRow( $res );
2571                         if ( $row ) {
2572                                 if ( $row['permission'] == 'sysop' ) {
2573                                         $row['permission'] = 'editprotected'; // B/C
2574                                 }
2575                                 if ( $row['permission'] == 'autoconfirmed' ) {
2576                                         $row['permission'] = 'editsemiprotected'; // B/C
2577                                 }
2578                                 $row['expiry'] = $dbr->decodeExpiry( $row['expiry'] );
2579                         }
2580                         $this->mTitleProtection = $row;
2581                 }
2582                 return $this->mTitleProtection;
2583         }
2584
2585         /**
2586          * Remove any title protection due to page existing
2587          */
2588         public function deleteTitleProtection() {
2589                 $dbw = wfGetDB( DB_MASTER );
2590
2591                 $dbw->delete(
2592                         'protected_titles',
2593                         [ 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ],
2594                         __METHOD__
2595                 );
2596                 $this->mTitleProtection = false;
2597         }
2598
2599         /**
2600          * Is this page "semi-protected" - the *only* protection levels are listed
2601          * in $wgSemiprotectedRestrictionLevels?
2602          *
2603          * @param string $action Action to check (default: edit)
2604          * @return bool
2605          */
2606         public function isSemiProtected( $action = 'edit' ) {
2607                 global $wgSemiprotectedRestrictionLevels;
2608
2609                 $restrictions = $this->getRestrictions( $action );
2610                 $semi = $wgSemiprotectedRestrictionLevels;
2611                 if ( !$restrictions || !$semi ) {
2612                         // Not protected, or all protection is full protection
2613                         return false;
2614                 }
2615
2616                 // Remap autoconfirmed to editsemiprotected for BC
2617                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2618                         $semi[$key] = 'editsemiprotected';
2619                 }
2620                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2621                         $restrictions[$key] = 'editsemiprotected';
2622                 }
2623
2624                 return !array_diff( $restrictions, $semi );
2625         }
2626
2627         /**
2628          * Does the title correspond to a protected article?
2629          *
2630          * @param string $action The action the page is protected from,
2631          * by default checks all actions.
2632          * @return bool
2633          */
2634         public function isProtected( $action = '' ) {
2635                 global $wgRestrictionLevels;
2636
2637                 $restrictionTypes = $this->getRestrictionTypes();
2638
2639                 # Special pages have inherent protection
2640                 if ( $this->isSpecialPage() ) {
2641                         return true;
2642                 }
2643
2644                 # Check regular protection levels
2645                 foreach ( $restrictionTypes as $type ) {
2646                         if ( $action == $type || $action == '' ) {
2647                                 $r = $this->getRestrictions( $type );
2648                                 foreach ( $wgRestrictionLevels as $level ) {
2649                                         if ( in_array( $level, $r ) && $level != '' ) {
2650                                                 return true;
2651                                         }
2652                                 }
2653                         }
2654                 }
2655
2656                 return false;
2657         }
2658
2659         /**
2660          * Determines if $user is unable to edit this page because it has been protected
2661          * by $wgNamespaceProtection.
2662          *
2663          * @param User $user User object to check permissions
2664          * @return bool
2665          */
2666         public function isNamespaceProtected( User $user ) {
2667                 global $wgNamespaceProtection;
2668
2669                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2670                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2671                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2672                                         return true;
2673                                 }
2674                         }
2675                 }
2676                 return false;
2677         }
2678
2679         /**
2680          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2681          *
2682          * @return bool If the page is subject to cascading restrictions.
2683          */
2684         public function isCascadeProtected() {
2685                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2686                 return ( $sources > 0 );
2687         }
2688
2689         /**
2690          * Determines whether cascading protection sources have already been loaded from
2691          * the database.
2692          *
2693          * @param bool $getPages True to check if the pages are loaded, or false to check
2694          * if the status is loaded.
2695          * @return bool Whether or not the specified information has been loaded
2696          * @since 1.23
2697          */
2698         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2699                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2700         }
2701
2702         /**
2703          * Cascading protection: Get the source of any cascading restrictions on this page.
2704          *
2705          * @param bool $getPages Whether or not to retrieve the actual pages
2706          *        that the restrictions have come from and the actual restrictions
2707          *        themselves.
2708          * @return array Two elements: First is an array of Title objects of the
2709          *        pages from which cascading restrictions have come, false for
2710          *        none, or true if such restrictions exist but $getPages was not
2711          *        set. Second is an array like that returned by
2712          *        Title::getAllRestrictions(), or an empty array if $getPages is
2713          *        false.
2714          */
2715         public function getCascadeProtectionSources( $getPages = true ) {
2716                 $pagerestrictions = [];
2717
2718                 if ( $this->mCascadeSources !== null && $getPages ) {
2719                         return [ $this->mCascadeSources, $this->mCascadingRestrictions ];
2720                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2721                         return [ $this->mHasCascadingRestrictions, $pagerestrictions ];
2722                 }
2723
2724                 $dbr = wfGetDB( DB_SLAVE );
2725
2726                 if ( $this->getNamespace() == NS_FILE ) {
2727                         $tables = [ 'imagelinks', 'page_restrictions' ];
2728                         $where_clauses = [
2729                                 'il_to' => $this->getDBkey(),
2730                                 'il_from=pr_page',
2731                                 'pr_cascade' => 1
2732                         ];
2733                 } else {
2734                         $tables = [ 'templatelinks', 'page_restrictions' ];
2735                         $where_clauses = [
2736                                 'tl_namespace' => $this->getNamespace(),
2737                                 'tl_title' => $this->getDBkey(),
2738                                 'tl_from=pr_page',
2739                                 'pr_cascade' => 1
2740                         ];
2741                 }
2742
2743                 if ( $getPages ) {
2744                         $cols = [ 'pr_page', 'page_namespace', 'page_title',
2745                                 'pr_expiry', 'pr_type', 'pr_level' ];
2746                         $where_clauses[] = 'page_id=pr_page';
2747                         $tables[] = 'page';
2748                 } else {
2749                         $cols = [ 'pr_expiry' ];
2750                 }
2751
2752                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2753
2754                 $sources = $getPages ? [] : false;
2755                 $now = wfTimestampNow();
2756
2757                 foreach ( $res as $row ) {
2758                         $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2759                         if ( $expiry > $now ) {
2760                                 if ( $getPages ) {
2761                                         $page_id = $row->pr_page;
2762                                         $page_ns = $row->page_namespace;
2763                                         $page_title = $row->page_title;
2764                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2765                                         # Add groups needed for each restriction type if its not already there
2766                                         # Make sure this restriction type still exists
2767
2768                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2769                                                 $pagerestrictions[$row->pr_type] = [];
2770                                         }
2771
2772                                         if (
2773                                                 isset( $pagerestrictions[$row->pr_type] )
2774                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2775                                         ) {
2776                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2777                                         }
2778                                 } else {
2779                                         $sources = true;
2780                                 }
2781                         }
2782                 }
2783
2784                 if ( $getPages ) {
2785                         $this->mCascadeSources = $sources;
2786                         $this->mCascadingRestrictions = $pagerestrictions;
2787                 } else {
2788                         $this->mHasCascadingRestrictions = $sources;
2789                 }
2790
2791                 return [ $sources, $pagerestrictions ];
2792         }
2793
2794         /**
2795          * Accessor for mRestrictionsLoaded
2796          *
2797          * @return bool Whether or not the page's restrictions have already been
2798          * loaded from the database
2799          * @since 1.23
2800          */
2801         public function areRestrictionsLoaded() {
2802                 return $this->mRestrictionsLoaded;
2803         }
2804
2805         /**
2806          * Accessor/initialisation for mRestrictions
2807          *
2808          * @param string $action Action that permission needs to be checked for
2809          * @return array Restriction levels needed to take the action. All levels are
2810          *     required. Note that restriction levels are normally user rights, but 'sysop'
2811          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2812          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2813          */
2814         public function getRestrictions( $action ) {
2815                 if ( !$this->mRestrictionsLoaded ) {
2816                         $this->loadRestrictions();
2817                 }
2818                 return isset( $this->mRestrictions[$action] )
2819                                 ? $this->mRestrictions[$action]
2820                                 : [];
2821         }
2822
2823         /**
2824          * Accessor/initialisation for mRestrictions
2825          *
2826          * @return array Keys are actions, values are arrays as returned by
2827          *     Title::getRestrictions()
2828          * @since 1.23
2829          */
2830         public function getAllRestrictions() {
2831                 if ( !$this->mRestrictionsLoaded ) {
2832                         $this->loadRestrictions();
2833                 }
2834                 return $this->mRestrictions;
2835         }
2836
2837         /**
2838          * Get the expiry time for the restriction against a given action
2839          *
2840          * @param string $action
2841          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2842          *     or not protected at all, or false if the action is not recognised.
2843          */
2844         public function getRestrictionExpiry( $action ) {
2845                 if ( !$this->mRestrictionsLoaded ) {
2846                         $this->loadRestrictions();
2847                 }
2848                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2849         }
2850
2851         /**
2852          * Returns cascading restrictions for the current article
2853          *
2854          * @return bool
2855          */
2856         function areRestrictionsCascading() {
2857                 if ( !$this->mRestrictionsLoaded ) {
2858                         $this->loadRestrictions();
2859                 }
2860
2861                 return $this->mCascadeRestriction;
2862         }
2863
2864         /**
2865          * Loads a string into mRestrictions array
2866          *
2867          * @param ResultWrapper $res Resource restrictions as an SQL result.
2868          * @param string $oldFashionedRestrictions Comma-separated list of page
2869          *        restrictions from page table (pre 1.10)
2870          */
2871         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2872                 $rows = [];
2873
2874                 foreach ( $res as $row ) {
2875                         $rows[] = $row;
2876                 }
2877
2878                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2879         }
2880
2881         /**
2882          * Compiles list of active page restrictions from both page table (pre 1.10)
2883          * and page_restrictions table for this existing page.
2884          * Public for usage by LiquidThreads.
2885          *
2886          * @param array $rows Array of db result objects
2887          * @param string $oldFashionedRestrictions Comma-separated list of page
2888          *   restrictions from page table (pre 1.10)
2889          */
2890         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2891                 $dbr = wfGetDB( DB_SLAVE );
2892
2893                 $restrictionTypes = $this->getRestrictionTypes();
2894
2895                 foreach ( $restrictionTypes as $type ) {
2896                         $this->mRestrictions[$type] = [];
2897                         $this->mRestrictionsExpiry[$type] = 'infinity';
2898                 }
2899
2900                 $this->mCascadeRestriction = false;
2901
2902                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2903                 if ( $oldFashionedRestrictions !== null ) {
2904                         $this->mOldRestrictions = $oldFashionedRestrictions;
2905                 }
2906
2907                 if ( $this->mOldRestrictions === false ) {
2908                         $this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2909                                 [ 'page_id' => $this->getArticleID() ], __METHOD__ );
2910                 }
2911
2912                 if ( $this->mOldRestrictions != '' ) {
2913                         foreach ( explode( ':', trim( $this->mOldRestrictions ) ) as $restrict ) {
2914                                 $temp = explode( '=', trim( $restrict ) );
2915                                 if ( count( $temp ) == 1 ) {
2916                                         // old old format should be treated as edit/move restriction
2917                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2918                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2919                                 } else {
2920                                         $restriction = trim( $temp[1] );
2921                                         if ( $restriction != '' ) { // some old entries are empty
2922                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2923                                         }
2924                                 }
2925                         }
2926                 }
2927
2928                 if ( count( $rows ) ) {
2929                         # Current system - load second to make them override.
2930                         $now = wfTimestampNow();
2931
2932                         # Cycle through all the restrictions.
2933                         foreach ( $rows as $row ) {
2934
2935                                 // Don't take care of restrictions types that aren't allowed
2936                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2937                                         continue;
2938                                 }
2939
2940                                 // This code should be refactored, now that it's being used more generally,
2941                                 // But I don't really see any harm in leaving it in Block for now -werdna
2942                                 $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2943
2944                                 // Only apply the restrictions if they haven't expired!
2945                                 if ( !$expiry || $expiry > $now ) {
2946                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2947                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2948
2949                                         $this->mCascadeRestriction |= $row->pr_cascade;
2950                                 }
2951                         }
2952                 }
2953
2954                 $this->mRestrictionsLoaded = true;
2955         }
2956
2957         /**
2958          * Load restrictions from the page_restrictions table
2959          *
2960          * @param string $oldFashionedRestrictions Comma-separated list of page
2961          *   restrictions from page table (pre 1.10)
2962          */
2963         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2964                 if ( !$this->mRestrictionsLoaded ) {
2965                         $dbr = wfGetDB( DB_SLAVE );
2966                         if ( $this->exists() ) {
2967                                 $res = $dbr->select(
2968                                         'page_restrictions',
2969                                         [ 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ],
2970                                         [ 'pr_page' => $this->getArticleID() ],
2971                                         __METHOD__
2972                                 );
2973
2974                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2975                         } else {
2976                                 $title_protection = $this->getTitleProtection();
2977
2978                                 if ( $title_protection ) {
2979                                         $now = wfTimestampNow();
2980                                         $expiry = $dbr->decodeExpiry( $title_protection['expiry'] );
2981
2982                                         if ( !$expiry || $expiry > $now ) {
2983                                                 // Apply the restrictions
2984                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2985                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
2986                                         } else { // Get rid of the old restrictions
2987                                                 $this->mTitleProtection = false;
2988                                         }
2989                                 } else {
2990                                         $this->mRestrictionsExpiry['create'] = 'infinity';
2991                                 }
2992                                 $this->mRestrictionsLoaded = true;
2993                         }
2994                 }
2995         }
2996
2997         /**
2998          * Flush the protection cache in this object and force reload from the database.
2999          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3000          */
3001         public function flushRestrictions() {
3002                 $this->mRestrictionsLoaded = false;
3003                 $this->mTitleProtection = null;
3004         }
3005
3006         /**
3007          * Purge expired restrictions from the page_restrictions table
3008          */
3009         static function purgeExpiredRestrictions() {
3010                 if ( wfReadOnly() ) {
3011                         return;
3012                 }
3013
3014                 DeferredUpdates::addUpdate( new AtomicSectionUpdate(
3015                         wfGetDB( DB_MASTER ),
3016                         __METHOD__,
3017                         function ( IDatabase $dbw, $fname ) {
3018                                 $dbw->delete(
3019                                         'page_restrictions',
3020                                         [ 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ],
3021                                         $fname
3022                                 );
3023                                 $dbw->delete(
3024                                         'protected_titles',
3025                                         [ 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ],
3026                                         $fname
3027                                 );
3028                         }
3029                 ) );
3030         }
3031
3032         /**
3033          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3034          *
3035          * @return bool
3036          */
3037         public function hasSubpages() {
3038                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3039                         # Duh
3040                         return false;
3041                 }
3042
3043                 # We dynamically add a member variable for the purpose of this method
3044                 # alone to cache the result.  There's no point in having it hanging
3045                 # around uninitialized in every Title object; therefore we only add it
3046                 # if needed and don't declare it statically.
3047                 if ( $this->mHasSubpages === null ) {
3048                         $this->mHasSubpages = false;
3049                         $subpages = $this->getSubpages( 1 );
3050                         if ( $subpages instanceof TitleArray ) {
3051                                 $this->mHasSubpages = (bool)$subpages->count();
3052                         }
3053                 }
3054
3055                 return $this->mHasSubpages;
3056         }
3057
3058         /**
3059          * Get all subpages of this page.
3060          *
3061          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3062          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3063          *  doesn't allow subpages
3064          */
3065         public function getSubpages( $limit = -1 ) {
3066                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3067                         return [];
3068                 }
3069
3070                 $dbr = wfGetDB( DB_SLAVE );
3071                 $conds['page_namespace'] = $this->getNamespace();
3072                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3073                 $options = [];
3074                 if ( $limit > -1 ) {
3075                         $options['LIMIT'] = $limit;
3076                 }
3077                 $this->mSubpages = TitleArray::newFromResult(
3078                         $dbr->select( 'page',
3079                                 [ 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ],
3080                                 $conds,
3081                                 __METHOD__,
3082                                 $options
3083                         )
3084                 );
3085                 return $this->mSubpages;
3086         }
3087
3088         /**
3089          * Is there a version of this page in the deletion archive?
3090          *
3091          * @return int The number of archived revisions
3092          */
3093         public function isDeleted() {
3094                 if ( $this->getNamespace() < 0 ) {
3095                         $n = 0;
3096                 } else {
3097                         $dbr = wfGetDB( DB_SLAVE );
3098
3099                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3100                                 [ 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ],
3101                                 __METHOD__
3102                         );
3103                         if ( $this->getNamespace() == NS_FILE ) {
3104                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3105                                         [ 'fa_name' => $this->getDBkey() ],
3106                                         __METHOD__
3107                                 );
3108                         }
3109                 }
3110                 return (int)$n;
3111         }
3112
3113         /**
3114          * Is there a version of this page in the deletion archive?
3115          *
3116          * @return bool
3117          */
3118         public function isDeletedQuick() {
3119                 if ( $this->getNamespace() < 0 ) {
3120                         return false;
3121                 }
3122                 $dbr = wfGetDB( DB_SLAVE );
3123                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3124                         [ 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ],
3125                         __METHOD__
3126                 );
3127                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3128                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3129                                 [ 'fa_name' => $this->getDBkey() ],
3130                                 __METHOD__
3131                         );
3132                 }
3133                 return $deleted;
3134         }
3135
3136         /**
3137          * Get the article ID for this Title from the link cache,
3138          * adding it if necessary
3139          *
3140          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3141          *  for update
3142          * @return int The ID
3143          */
3144         public function getArticleID( $flags = 0 ) {
3145                 if ( $this->getNamespace() < 0 ) {
3146                         $this->mArticleID = 0;
3147                         return $this->mArticleID;
3148                 }
3149                 $linkCache = LinkCache::singleton();
3150                 if ( $flags & self::GAID_FOR_UPDATE ) {
3151                         $oldUpdate = $linkCache->forUpdate( true );
3152                         $linkCache->clearLink( $this );
3153                         $this->mArticleID = $linkCache->addLinkObj( $this );
3154                         $linkCache->forUpdate( $oldUpdate );
3155                 } else {
3156                         if ( -1 == $this->mArticleID ) {
3157                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3158                         }
3159                 }
3160                 return $this->mArticleID;
3161         }
3162
3163         /**
3164          * Is this an article that is a redirect page?
3165          * Uses link cache, adding it if necessary
3166          *
3167          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3168          * @return bool
3169          */
3170         public function isRedirect( $flags = 0 ) {
3171                 if ( !is_null( $this->mRedirect ) ) {
3172                         return $this->mRedirect;
3173                 }
3174                 if ( !$this->getArticleID( $flags ) ) {
3175                         $this->mRedirect = false;
3176                         return $this->mRedirect;
3177                 }
3178
3179                 $linkCache = LinkCache::singleton();
3180                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3181                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3182                 if ( $cached === null ) {
3183                         # Trust LinkCache's state over our own
3184                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3185                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3186                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3187                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3188                         # LinkCache to refresh its data from the master.
3189                         $this->mRedirect = false;
3190                         return $this->mRedirect;
3191                 }
3192
3193                 $this->mRedirect = (bool)$cached;
3194
3195                 return $this->mRedirect;
3196         }
3197
3198         /**
3199          * What is the length of this page?
3200          * Uses link cache, adding it if necessary
3201          *
3202          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3203          * @return int
3204          */
3205         public function getLength( $flags = 0 ) {
3206                 if ( $this->mLength != -1 ) {
3207                         return $this->mLength;
3208                 }
3209                 if ( !$this->getArticleID( $flags ) ) {
3210                         $this->mLength = 0;
3211                         return $this->mLength;
3212                 }
3213                 $linkCache = LinkCache::singleton();
3214                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3215                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3216                 if ( $cached === null ) {
3217                         # Trust LinkCache's state over our own, as for isRedirect()
3218                         $this->mLength = 0;
3219                         return $this->mLength;
3220                 }
3221
3222                 $this->mLength = intval( $cached );
3223
3224                 return $this->mLength;
3225         }
3226
3227         /**
3228          * What is the page_latest field for this page?
3229          *
3230          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3231          * @return int Int or 0 if the page doesn't exist
3232          */
3233         public function getLatestRevID( $flags = 0 ) {
3234                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3235                         return intval( $this->mLatestID );
3236                 }
3237                 if ( !$this->getArticleID( $flags ) ) {
3238                         $this->mLatestID = 0;
3239                         return $this->mLatestID;
3240                 }
3241                 $linkCache = LinkCache::singleton();
3242                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3243                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3244                 if ( $cached === null ) {
3245                         # Trust LinkCache's state over our own, as for isRedirect()
3246                         $this->mLatestID = 0;
3247                         return $this->mLatestID;
3248                 }
3249
3250                 $this->mLatestID = intval( $cached );
3251
3252                 return $this->mLatestID;
3253         }
3254
3255         /**
3256          * This clears some fields in this object, and clears any associated
3257          * keys in the "bad links" section of the link cache.
3258          *
3259          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3260          * loading of the new page_id. It's also called from
3261          * WikiPage::doDeleteArticleReal()
3262          *
3263          * @param int $newid The new Article ID
3264          */
3265         public function resetArticleID( $newid ) {
3266                 $linkCache = LinkCache::singleton();
3267                 $linkCache->clearLink( $this );
3268
3269                 if ( $newid === false ) {
3270                         $this->mArticleID = -1;
3271                 } else {
3272                         $this->mArticleID = intval( $newid );
3273                 }
3274                 $this->mRestrictionsLoaded = false;
3275                 $this->mRestrictions = [];
3276                 $this->mOldRestrictions = false;
3277                 $this->mRedirect = null;
3278                 $this->mLength = -1;
3279                 $this->mLatestID = false;
3280                 $this->mContentModel = false;
3281                 $this->mEstimateRevisions = null;
3282                 $this->mPageLanguage = false;
3283                 $this->mDbPageLanguage = false;
3284                 $this->mIsBigDeletion = null;
3285         }
3286
3287         public static function clearCaches() {
3288                 $linkCache = LinkCache::singleton();
3289                 $linkCache->clear();
3290
3291                 $titleCache = self::getTitleCache();
3292                 $titleCache->clear();
3293         }
3294
3295         /**
3296          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3297          *
3298          * @param string $text Containing title to capitalize
3299          * @param int $ns Namespace index, defaults to NS_MAIN
3300          * @return string Containing capitalized title
3301          */
3302         public static function capitalize( $text, $ns = NS_MAIN ) {
3303                 global $wgContLang;
3304
3305                 if ( MWNamespace::isCapitalized( $ns ) ) {
3306                         return $wgContLang->ucfirst( $text );
3307                 } else {
3308                         return $text;
3309                 }
3310         }
3311
3312         /**
3313          * Secure and split - main initialisation function for this object
3314          *
3315          * Assumes that mDbkeyform has been set, and is urldecoded
3316          * and uses underscores, but not otherwise munged.  This function
3317          * removes illegal characters, splits off the interwiki and
3318          * namespace prefixes, sets the other forms, and canonicalizes
3319          * everything.
3320          *
3321          * @throws MalformedTitleException On invalid titles
3322          * @return bool True on success
3323          */
3324         private function secureAndSplit() {
3325                 # Initialisation
3326                 $this->mInterwiki = '';
3327                 $this->mFragment = '';
3328                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3329
3330                 $dbkey = $this->mDbkeyform;
3331
3332                 // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3333                 //        the parsing code with Title, while avoiding massive refactoring.
3334                 // @todo: get rid of secureAndSplit, refactor parsing code.
3335                 $titleParser = self::getMediaWikiTitleCodec();
3336                 // MalformedTitleException can be thrown here
3337                 $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3338
3339                 # Fill fields
3340                 $this->setFragment( '#' . $parts['fragment'] );
3341                 $this->mInterwiki = $parts['interwiki'];
3342                 $this->mLocalInterwiki = $parts['local_interwiki'];
3343                 $this->mNamespace = $parts['namespace'];
3344                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3345
3346                 $this->mDbkeyform = $parts['dbkey'];
3347                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3348                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
3349
3350                 # We already know that some pages won't be in the database!
3351                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3352                         $this->mArticleID = 0;
3353                 }
3354
3355                 return true;
3356         }
3357
3358         /**
3359          * Get an array of Title objects linking to this Title
3360          * Also stores the IDs in the link cache.
3361          *
3362          * WARNING: do not use this function on arbitrary user-supplied titles!
3363          * On heavily-used templates it will max out the memory.
3364          *
3365          * @param array $options May be FOR UPDATE
3366          * @param string $table Table name
3367          * @param string $prefix Fields prefix
3368          * @return Title[] Array of Title objects linking here
3369          */
3370         public function getLinksTo( $options = [], $table = 'pagelinks', $prefix = 'pl' ) {
3371                 if ( count( $options ) > 0 ) {
3372                         $db = wfGetDB( DB_MASTER );
3373                 } else {
3374                         $db = wfGetDB( DB_SLAVE );
3375                 }
3376
3377                 $res = $db->select(
3378                         [ 'page', $table ],
3379                         self::getSelectFields(),
3380                         [
3381                                 "{$prefix}_from=page_id",
3382                                 "{$prefix}_namespace" => $this->getNamespace(),
3383                                 "{$prefix}_title" => $this->getDBkey() ],
3384                         __METHOD__,
3385                         $options
3386                 );
3387
3388                 $retVal = [];
3389                 if ( $res->numRows() ) {
3390                         $linkCache = LinkCache::singleton();
3391                         foreach ( $res as $row ) {
3392                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3393                                 if ( $titleObj ) {
3394                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3395                                         $retVal[] = $titleObj;
3396                                 }
3397                         }
3398                 }
3399                 return $retVal;
3400         }
3401
3402         /**
3403          * Get an array of Title objects using this Title as a template
3404          * Also stores the IDs in the link cache.
3405          *
3406          * WARNING: do not use this function on arbitrary user-supplied titles!
3407          * On heavily-used templates it will max out the memory.
3408          *
3409          * @param array $options Query option to Database::select()
3410          * @return Title[] Array of Title the Title objects linking here
3411          */
3412         public function getTemplateLinksTo( $options = [] ) {
3413                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3414         }
3415
3416         /**
3417          * Get an array of Title objects linked from this Title
3418          * Also stores the IDs in the link cache.
3419          *
3420          * WARNING: do not use this function on arbitrary user-supplied titles!
3421          * On heavily-used templates it will max out the memory.
3422          *
3423          * @param array $options Query option to Database::select()
3424          * @param string $table Table name
3425          * @param string $prefix Fields prefix
3426          * @return array Array of Title objects linking here
3427          */
3428         public function getLinksFrom( $options = [], $table = 'pagelinks', $prefix = 'pl' ) {
3429                 $id = $this->getArticleID();
3430
3431                 # If the page doesn't exist; there can't be any link from this page
3432                 if ( !$id ) {
3433                         return [];
3434                 }
3435
3436                 $db = wfGetDB( DB_SLAVE );
3437
3438                 $blNamespace = "{$prefix}_namespace";
3439                 $blTitle = "{$prefix}_title";
3440
3441                 $res = $db->select(
3442                         [ $table, 'page' ],
3443                         array_merge(
3444                                 [ $blNamespace, $blTitle ],
3445                                 WikiPage::selectFields()
3446                         ),
3447                         [ "{$prefix}_from" => $id ],
3448                         __METHOD__,
3449                         $options,
3450                         [ 'page' => [
3451                                 'LEFT JOIN',
3452                                 [ "page_namespace=$blNamespace", "page_title=$blTitle" ]
3453                         ] ]
3454                 );
3455
3456                 $retVal = [];
3457                 $linkCache = LinkCache::singleton();
3458                 foreach ( $res as $row ) {
3459                         if ( $row->page_id ) {
3460                                 $titleObj = Title::newFromRow( $row );
3461                         } else {
3462                                 $titleObj = Title::makeTitle( $row->$blNamespace, $row->$blTitle );
3463                                 $linkCache->addBadLinkObj( $titleObj );
3464                         }
3465                         $retVal[] = $titleObj;
3466                 }
3467
3468                 return $retVal;
3469         }
3470
3471         /**
3472          * Get an array of Title objects used on this Title as a template
3473          * Also stores the IDs in the link cache.
3474          *
3475          * WARNING: do not use this function on arbitrary user-supplied titles!
3476          * On heavily-used templates it will max out the memory.
3477          *
3478          * @param array $options May be FOR UPDATE
3479          * @return Title[] Array of Title the Title objects used here
3480          */
3481         public function getTemplateLinksFrom( $options = [] ) {
3482                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3483         }
3484
3485         /**
3486          * Get an array of Title objects referring to non-existent articles linked
3487          * from this page.
3488          *
3489          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3490          *   should use redirect table in this case).
3491          * @return Title[] Array of Title the Title objects
3492          */
3493         public function getBrokenLinksFrom() {
3494                 if ( $this->getArticleID() == 0 ) {
3495                         # All links from article ID 0 are false positives
3496                         return [];
3497                 }
3498
3499                 $dbr = wfGetDB( DB_SLAVE );
3500                 $res = $dbr->select(
3501                         [ 'page', 'pagelinks' ],
3502                         [ 'pl_namespace', 'pl_title' ],
3503                         [
3504                                 'pl_from' => $this->getArticleID(),
3505                                 'page_namespace IS NULL'
3506                         ],
3507                         __METHOD__, [],
3508                         [
3509                                 'page' => [
3510                                         'LEFT JOIN',
3511                                         [ 'pl_namespace=page_namespace', 'pl_title=page_title' ]
3512                                 ]
3513                         ]
3514                 );
3515
3516                 $retVal = [];
3517                 foreach ( $res as $row ) {
3518                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3519                 }
3520                 return $retVal;
3521         }
3522
3523         /**
3524          * Get a list of URLs to purge from the CDN cache when this
3525          * page changes
3526          *
3527          * @return string[] Array of String the URLs
3528          */
3529         public function getCdnUrls() {
3530                 $urls = [
3531                         $this->getInternalURL(),
3532                         $this->getInternalURL( 'action=history' )
3533                 ];
3534
3535                 $pageLang = $this->getPageLanguage();
3536                 if ( $pageLang->hasVariants() ) {
3537                         $variants = $pageLang->getVariants();
3538                         foreach ( $variants as $vCode ) {
3539                                 $urls[] = $this->getInternalURL( $vCode );
3540                         }
3541                 }
3542
3543                 // If we are looking at a css/js user subpage, purge the action=raw.
3544                 if ( $this->isJsSubpage() ) {
3545                         $urls[] = $this->getInternalURL( 'action=raw&ctype=text/javascript' );
3546                 } elseif ( $this->isCssSubpage() ) {
3547                         $urls[] = $this->getInternalURL( 'action=raw&ctype=text/css' );
3548                 }
3549
3550                 Hooks::run( 'TitleSquidURLs', [ $this, &$urls ] );
3551                 return $urls;
3552         }
3553
3554         /**
3555          * @deprecated since 1.27 use getCdnUrls()
3556          */
3557         public function getSquidURLs() {
3558                 return $this->getCdnUrls();
3559         }
3560
3561         /**
3562          * Purge all applicable CDN URLs
3563          */
3564         public function purgeSquid() {
3565                 DeferredUpdates::addUpdate(
3566                         new CdnCacheUpdate( $this->getCdnUrls() ),
3567                         DeferredUpdates::PRESEND
3568                 );
3569         }
3570
3571         /**
3572          * Move this page without authentication
3573          *
3574          * @deprecated since 1.25 use MovePage class instead
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                 wfDeprecated( __METHOD__, '1.25' );
3580                 return $this->moveTo( $nt, false );
3581         }
3582
3583         /**
3584          * Check whether a given move operation would be valid.
3585          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3586          *
3587          * @deprecated since 1.25, use MovePage's methods instead
3588          * @param Title $nt The new title
3589          * @param bool $auth Whether to check user permissions (uses $wgUser)
3590          * @param string $reason Is the log summary of the move, used for spam checking
3591          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3592          */
3593         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3594                 global $wgUser;
3595
3596                 if ( !( $nt instanceof Title ) ) {
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 [ [ 'badtitletext' ] ];
3600                 }
3601
3602                 $mp = new MovePage( $this, $nt );
3603                 $errors = $mp->isValidMove()->getErrorsArray();
3604                 if ( $auth ) {
3605                         $errors = wfMergeErrorArrays(
3606                                 $errors,
3607                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3608                         );
3609                 }
3610
3611                 return $errors ?: true;
3612         }
3613
3614         /**
3615          * Check if the requested move target is a valid file move target
3616          * @todo move this to MovePage
3617          * @param Title $nt Target title
3618          * @return array List of errors
3619          */
3620         protected function validateFileMoveOperation( $nt ) {
3621                 global $wgUser;
3622
3623                 $errors = [];
3624
3625                 $destFile = wfLocalFile( $nt );
3626                 $destFile->load( File::READ_LATEST );
3627                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3628                         && !$destFile->exists() && wfFindFile( $nt )
3629                 ) {
3630                         $errors[] = [ 'file-exists-sharedrepo' ];
3631                 }
3632
3633                 return $errors;
3634         }
3635
3636         /**
3637          * Move a title to a new location
3638          *
3639          * @deprecated since 1.25, use the MovePage class instead
3640          * @param Title $nt The new title
3641          * @param bool $auth Indicates whether $wgUser's permissions
3642          *  should be checked
3643          * @param string $reason The reason for the move
3644          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3645          *  Ignored if the user doesn't have the suppressredirect right.
3646          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3647          */
3648         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3649                 global $wgUser;
3650                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3651                 if ( is_array( $err ) ) {
3652                         // Auto-block user's IP if the account was "hard" blocked
3653                         $wgUser->spreadAnyEditBlock();
3654                         return $err;
3655                 }
3656                 // Check suppressredirect permission
3657                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3658                         $createRedirect = true;
3659                 }
3660
3661                 $mp = new MovePage( $this, $nt );
3662                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3663                 if ( $status->isOK() ) {
3664                         return true;
3665                 } else {
3666                         return $status->getErrorsArray();
3667                 }
3668         }
3669
3670         /**
3671          * Move this page's subpages to be subpages of $nt
3672          *
3673          * @param Title $nt Move target
3674          * @param bool $auth Whether $wgUser's permissions should be checked
3675          * @param string $reason The reason for the move
3676          * @param bool $createRedirect Whether to create redirects from the old subpages to
3677          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3678          * @return array Array with old page titles as keys, and strings (new page titles) or
3679          *     arrays (errors) as values, or an error array with numeric indices if no pages
3680          *     were moved
3681          */
3682         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3683                 global $wgMaximumMovedPages;
3684                 // Check permissions
3685                 if ( !$this->userCan( 'move-subpages' ) ) {
3686                         return [ 'cant-move-subpages' ];
3687                 }
3688                 // Do the source and target namespaces support subpages?
3689                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3690                         return [ 'namespace-nosubpages',
3691                                 MWNamespace::getCanonicalName( $this->getNamespace() ) ];
3692                 }
3693                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3694                         return [ 'namespace-nosubpages',
3695                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) ];
3696                 }
3697
3698                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3699                 $retval = [];
3700                 $count = 0;
3701                 foreach ( $subpages as $oldSubpage ) {
3702                         $count++;
3703                         if ( $count > $wgMaximumMovedPages ) {
3704                                 $retval[$oldSubpage->getPrefixedText()] =
3705                                                 [ 'movepage-max-pages',
3706                                                         $wgMaximumMovedPages ];
3707                                 break;
3708                         }
3709
3710                         // We don't know whether this function was called before
3711                         // or after moving the root page, so check both
3712                         // $this and $nt
3713                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3714                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3715                         ) {
3716                                 // When moving a page to a subpage of itself,
3717                                 // don't move it twice
3718                                 continue;
3719                         }
3720                         $newPageName = preg_replace(
3721                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3722                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3723                                         $oldSubpage->getDBkey() );
3724                         if ( $oldSubpage->isTalkPage() ) {
3725                                 $newNs = $nt->getTalkPage()->getNamespace();
3726                         } else {
3727                                 $newNs = $nt->getSubjectPage()->getNamespace();
3728                         }
3729                         # Bug 14385: we need makeTitleSafe because the new page names may
3730                         # be longer than 255 characters.
3731                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3732
3733                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3734                         if ( $success === true ) {
3735                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3736                         } else {
3737                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3738                         }
3739                 }
3740                 return $retval;
3741         }
3742
3743         /**
3744          * Checks if this page is just a one-rev redirect.
3745          * Adds lock, so don't use just for light purposes.
3746          *
3747          * @return bool
3748          */
3749         public function isSingleRevRedirect() {
3750                 global $wgContentHandlerUseDB;
3751
3752                 $dbw = wfGetDB( DB_MASTER );
3753
3754                 # Is it a redirect?
3755                 $fields = [ 'page_is_redirect', 'page_latest', 'page_id' ];
3756                 if ( $wgContentHandlerUseDB ) {
3757                         $fields[] = 'page_content_model';
3758                 }
3759
3760                 $row = $dbw->selectRow( 'page',
3761                         $fields,
3762                         $this->pageCond(),
3763                         __METHOD__,
3764                         [ 'FOR UPDATE' ]
3765                 );
3766                 # Cache some fields we may want
3767                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3768                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3769                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3770                 $this->mContentModel = $row && isset( $row->page_content_model )
3771                         ? strval( $row->page_content_model )
3772                         : false;
3773
3774                 if ( !$this->mRedirect ) {
3775                         return false;
3776                 }
3777                 # Does the article have a history?
3778                 $row = $dbw->selectField( [ 'page', 'revision' ],
3779                         'rev_id',
3780                         [ 'page_namespace' => $this->getNamespace(),
3781                                 'page_title' => $this->getDBkey(),
3782                                 'page_id=rev_page',
3783                                 'page_latest != rev_id'
3784                         ],
3785                         __METHOD__,
3786                         [ 'FOR UPDATE' ]
3787                 );
3788                 # Return true if there was no history
3789                 return ( $row === false );
3790         }
3791
3792         /**
3793          * Checks if $this can be moved to a given Title
3794          * - Selects for update, so don't call it unless you mean business
3795          *
3796          * @deprecated since 1.25, use MovePage's methods instead
3797          * @param Title $nt The new title to check
3798          * @return bool
3799          */
3800         public function isValidMoveTarget( $nt ) {
3801                 # Is it an existing file?
3802                 if ( $nt->getNamespace() == NS_FILE ) {
3803                         $file = wfLocalFile( $nt );
3804                         $file->load( File::READ_LATEST );
3805                         if ( $file->exists() ) {
3806                                 wfDebug( __METHOD__ . ": file exists\n" );
3807                                 return false;
3808                         }
3809                 }
3810                 # Is it a redirect with no history?
3811                 if ( !$nt->isSingleRevRedirect() ) {
3812                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3813                         return false;
3814                 }
3815                 # Get the article text
3816                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3817                 if ( !is_object( $rev ) ) {
3818                         return false;
3819                 }
3820                 $content = $rev->getContent();
3821                 # Does the redirect point to the source?
3822                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3823                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3824
3825                 if ( $redirTitle ) {
3826                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3827                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3828                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3829                                 return false;
3830                         } else {
3831                                 return true;
3832                         }
3833                 } else {
3834                         # Fail safe (not a redirect after all. strange.)
3835                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3836                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3837                         return false;
3838                 }
3839         }
3840
3841         /**
3842          * Get categories to which this Title belongs and return an array of
3843          * categories' names.
3844          *
3845          * @return array Array of parents in the form:
3846          *        $parent => $currentarticle
3847          */
3848         public function getParentCategories() {
3849                 global $wgContLang;
3850
3851                 $data = [];
3852
3853                 $titleKey = $this->getArticleID();
3854
3855                 if ( $titleKey === 0 ) {
3856                         return $data;
3857                 }
3858
3859                 $dbr = wfGetDB( DB_SLAVE );
3860
3861                 $res = $dbr->select(
3862                         'categorylinks',
3863                         'cl_to',
3864                         [ 'cl_from' => $titleKey ],
3865                         __METHOD__
3866                 );
3867
3868                 if ( $res->numRows() > 0 ) {
3869                         foreach ( $res as $row ) {
3870                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3871                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3872                         }
3873                 }
3874                 return $data;
3875         }
3876
3877         /**
3878          * Get a tree of parent categories
3879          *
3880          * @param array $children Array with the children in the keys, to check for circular refs
3881          * @return array Tree of parent categories
3882          */
3883         public function getParentCategoryTree( $children = [] ) {
3884                 $stack = [];
3885                 $parents = $this->getParentCategories();
3886
3887                 if ( $parents ) {
3888                         foreach ( $parents as $parent => $current ) {
3889                                 if ( array_key_exists( $parent, $children ) ) {
3890                                         # Circular reference
3891                                         $stack[$parent] = [];
3892                                 } else {
3893                                         $nt = Title::newFromText( $parent );
3894                                         if ( $nt ) {
3895                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + [ $parent => 1 ] );
3896                                         }
3897                                 }
3898                         }
3899                 }
3900
3901                 return $stack;
3902         }
3903
3904         /**
3905          * Get an associative array for selecting this title from
3906          * the "page" table
3907          *
3908          * @return array Array suitable for the $where parameter of DB::select()
3909          */
3910         public function pageCond() {
3911                 if ( $this->mArticleID > 0 ) {
3912                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3913                         return [ 'page_id' => $this->mArticleID ];
3914                 } else {
3915                         return [ 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform ];
3916                 }
3917         }
3918
3919         /**
3920          * Get the revision ID of the previous revision
3921          *
3922          * @param int $revId Revision ID. Get the revision that was before this one.
3923          * @param int $flags Title::GAID_FOR_UPDATE
3924          * @return int|bool Old revision ID, or false if none exists
3925          */
3926         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3927                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3928                 $revId = $db->selectField( 'revision', 'rev_id',
3929                         [
3930                                 'rev_page' => $this->getArticleID( $flags ),
3931                                 'rev_id < ' . intval( $revId )
3932                         ],
3933                         __METHOD__,
3934                         [ 'ORDER BY' => 'rev_id DESC' ]
3935                 );
3936
3937                 if ( $revId === false ) {
3938                         return false;
3939                 } else {
3940                         return intval( $revId );
3941                 }
3942         }
3943
3944         /**
3945          * Get the revision ID of the next revision
3946          *
3947          * @param int $revId Revision ID. Get the revision that was after this one.
3948          * @param int $flags Title::GAID_FOR_UPDATE
3949          * @return int|bool Next revision ID, or false if none exists
3950          */
3951         public function getNextRevisionID( $revId, $flags = 0 ) {
3952                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3953                 $revId = $db->selectField( 'revision', 'rev_id',
3954                         [
3955                                 'rev_page' => $this->getArticleID( $flags ),
3956                                 'rev_id > ' . intval( $revId )
3957                         ],
3958                         __METHOD__,
3959                         [ 'ORDER BY' => 'rev_id' ]
3960                 );
3961
3962                 if ( $revId === false ) {
3963                         return false;
3964                 } else {
3965                         return intval( $revId );
3966                 }
3967         }
3968
3969         /**
3970          * Get the first revision of the page
3971          *
3972          * @param int $flags Title::GAID_FOR_UPDATE
3973          * @return Revision|null If page doesn't exist
3974          */
3975         public function getFirstRevision( $flags = 0 ) {
3976                 $pageId = $this->getArticleID( $flags );
3977                 if ( $pageId ) {
3978                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3979                         $row = $db->selectRow( 'revision', Revision::selectFields(),
3980                                 [ 'rev_page' => $pageId ],
3981                                 __METHOD__,
3982                                 [ 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 ]
3983                         );
3984                         if ( $row ) {
3985                                 return new Revision( $row );
3986                         }
3987                 }
3988                 return null;
3989         }
3990
3991         /**
3992          * Get the oldest revision timestamp of this page
3993          *
3994          * @param int $flags Title::GAID_FOR_UPDATE
3995          * @return string MW timestamp
3996          */
3997         public function getEarliestRevTime( $flags = 0 ) {
3998                 $rev = $this->getFirstRevision( $flags );
3999                 return $rev ? $rev->getTimestamp() : null;
4000         }
4001
4002         /**
4003          * Check if this is a new page
4004          *
4005          * @return bool
4006          */
4007         public function isNewPage() {
4008                 $dbr = wfGetDB( DB_SLAVE );
4009                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4010         }
4011
4012         /**
4013          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4014          *
4015          * @return bool
4016          */
4017         public function isBigDeletion() {
4018                 global $wgDeleteRevisionsLimit;
4019
4020                 if ( !$wgDeleteRevisionsLimit ) {
4021                         return false;
4022                 }
4023
4024                 if ( $this->mIsBigDeletion === null ) {
4025                         $dbr = wfGetDB( DB_SLAVE );
4026
4027                         $revCount = $dbr->selectRowCount(
4028                                 'revision',
4029                                 '1',
4030                                 [ 'rev_page' => $this->getArticleID() ],
4031                                 __METHOD__,
4032                                 [ 'LIMIT' => $wgDeleteRevisionsLimit + 1 ]
4033                         );
4034
4035                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4036                 }
4037
4038                 return $this->mIsBigDeletion;
4039         }
4040
4041         /**
4042          * Get the approximate revision count of this page.
4043          *
4044          * @return int
4045          */
4046         public function estimateRevisionCount() {
4047                 if ( !$this->exists() ) {
4048                         return 0;
4049                 }
4050
4051                 if ( $this->mEstimateRevisions === null ) {
4052                         $dbr = wfGetDB( DB_SLAVE );
4053                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4054                                 [ 'rev_page' => $this->getArticleID() ], __METHOD__ );
4055                 }
4056
4057                 return $this->mEstimateRevisions;
4058         }
4059
4060         /**
4061          * Get the number of revisions between the given revision.
4062          * Used for diffs and other things that really need it.
4063          *
4064          * @param int|Revision $old Old revision or rev ID (first before range)
4065          * @param int|Revision $new New revision or rev ID (first after range)
4066          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4067          * @return int Number of revisions between these revisions.
4068          */
4069         public function countRevisionsBetween( $old, $new, $max = null ) {
4070                 if ( !( $old instanceof Revision ) ) {
4071                         $old = Revision::newFromTitle( $this, (int)$old );
4072                 }
4073                 if ( !( $new instanceof Revision ) ) {
4074                         $new = Revision::newFromTitle( $this, (int)$new );
4075                 }
4076                 if ( !$old || !$new ) {
4077                         return 0; // nothing to compare
4078                 }
4079                 $dbr = wfGetDB( DB_SLAVE );
4080                 $conds = [
4081                         'rev_page' => $this->getArticleID(),
4082                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4083                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4084                 ];
4085                 if ( $max !== null ) {
4086                         return $dbr->selectRowCount( 'revision', '1',
4087                                 $conds,
4088                                 __METHOD__,
4089                                 [ 'LIMIT' => $max + 1 ] // extra to detect truncation
4090                         );
4091                 } else {
4092                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4093                 }
4094         }
4095
4096         /**
4097          * Get the authors between the given revisions or revision IDs.
4098          * Used for diffs and other things that really need it.
4099          *
4100          * @since 1.23
4101          *
4102          * @param int|Revision $old Old revision or rev ID (first before range by default)
4103          * @param int|Revision $new New revision or rev ID (first after range by default)
4104          * @param int $limit Maximum number of authors
4105          * @param string|array $options (Optional): Single option, or an array of options:
4106          *     'include_old' Include $old in the range; $new is excluded.
4107          *     'include_new' Include $new in the range; $old is excluded.
4108          *     'include_both' Include both $old and $new in the range.
4109          *     Unknown option values are ignored.
4110          * @return array|null Names of revision authors in the range; null if not both revisions exist
4111          */
4112         public function getAuthorsBetween( $old, $new, $limit, $options = [] ) {
4113                 if ( !( $old instanceof Revision ) ) {
4114                         $old = Revision::newFromTitle( $this, (int)$old );
4115                 }
4116                 if ( !( $new instanceof Revision ) ) {
4117                         $new = Revision::newFromTitle( $this, (int)$new );
4118                 }
4119                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4120                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4121                 // in the sanity check below?
4122                 if ( !$old || !$new ) {
4123                         return null; // nothing to compare
4124                 }
4125                 $authors = [];
4126                 $old_cmp = '>';
4127                 $new_cmp = '<';
4128                 $options = (array)$options;
4129                 if ( in_array( 'include_old', $options ) ) {
4130                         $old_cmp = '>=';
4131                 }
4132                 if ( in_array( 'include_new', $options ) ) {
4133                         $new_cmp = '<=';
4134                 }
4135                 if ( in_array( 'include_both', $options ) ) {
4136                         $old_cmp = '>=';
4137                         $new_cmp = '<=';
4138                 }
4139                 // No DB query needed if $old and $new are the same or successive revisions:
4140                 if ( $old->getId() === $new->getId() ) {
4141                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4142                                 [] :
4143                                 [ $old->getUserText( Revision::RAW ) ];
4144                 } elseif ( $old->getId() === $new->getParentId() ) {
4145                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4146                                 $authors[] = $old->getUserText( Revision::RAW );
4147                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4148                                         $authors[] = $new->getUserText( Revision::RAW );
4149                                 }
4150                         } elseif ( $old_cmp === '>=' ) {
4151                                 $authors[] = $old->getUserText( Revision::RAW );
4152                         } elseif ( $new_cmp === '<=' ) {
4153                                 $authors[] = $new->getUserText( Revision::RAW );
4154                         }
4155                         return $authors;
4156                 }
4157                 $dbr = wfGetDB( DB_SLAVE );
4158                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4159                         [
4160                                 'rev_page' => $this->getArticleID(),
4161                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4162                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4163                         ], __METHOD__,
4164                         [ 'LIMIT' => $limit + 1 ] // add one so caller knows it was truncated
4165                 );
4166                 foreach ( $res as $row ) {
4167                         $authors[] = $row->rev_user_text;
4168                 }
4169                 return $authors;
4170         }
4171
4172         /**
4173          * Get the number of authors between the given revisions or revision IDs.
4174          * Used for diffs and other things that really need it.
4175          *
4176          * @param int|Revision $old Old revision or rev ID (first before range by default)
4177          * @param int|Revision $new New revision or rev ID (first after range by default)
4178          * @param int $limit Maximum number of authors
4179          * @param string|array $options (Optional): Single option, or an array of options:
4180          *     'include_old' Include $old in the range; $new is excluded.
4181          *     'include_new' Include $new in the range; $old is excluded.
4182          *     'include_both' Include both $old and $new in the range.
4183          *     Unknown option values are ignored.
4184          * @return int Number of revision authors in the range; zero if not both revisions exist
4185          */
4186         public function countAuthorsBetween( $old, $new, $limit, $options = [] ) {
4187                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4188                 return $authors ? count( $authors ) : 0;
4189         }
4190
4191         /**
4192          * Compare with another title.
4193          *
4194          * @param Title $title
4195          * @return bool
4196          */
4197         public function equals( Title $title ) {
4198                 // Note: === is necessary for proper matching of number-like titles.
4199                 return $this->getInterwiki() === $title->getInterwiki()
4200                         && $this->getNamespace() == $title->getNamespace()
4201                         && $this->getDBkey() === $title->getDBkey();
4202         }
4203
4204         /**
4205          * Check if this title is a subpage of another title
4206          *
4207          * @param Title $title
4208          * @return bool
4209          */
4210         public function isSubpageOf( Title $title ) {
4211                 return $this->getInterwiki() === $title->getInterwiki()
4212                         && $this->getNamespace() == $title->getNamespace()
4213                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4214         }
4215
4216         /**
4217          * Check if page exists.  For historical reasons, this function simply
4218          * checks for the existence of the title in the page table, and will
4219          * thus return false for interwiki links, special pages and the like.
4220          * If you want to know if a title can be meaningfully viewed, you should
4221          * probably call the isKnown() method instead.
4222          *
4223          * @param int $flags An optional bit field; may be Title::GAID_FOR_UPDATE to check
4224          *   from master/for update
4225          * @return bool
4226          */
4227         public function exists( $flags = 0 ) {
4228                 $exists = $this->getArticleID( $flags ) != 0;
4229                 Hooks::run( 'TitleExists', [ $this, &$exists ] );
4230                 return $exists;
4231         }
4232
4233         /**
4234          * Should links to this title be shown as potentially viewable (i.e. as
4235          * "bluelinks"), even if there's no record by this title in the page
4236          * table?
4237          *
4238          * This function is semi-deprecated for public use, as well as somewhat
4239          * misleadingly named.  You probably just want to call isKnown(), which
4240          * calls this function internally.
4241          *
4242          * (ISSUE: Most of these checks are cheap, but the file existence check
4243          * can potentially be quite expensive.  Including it here fixes a lot of
4244          * existing code, but we might want to add an optional parameter to skip
4245          * it and any other expensive checks.)
4246          *
4247          * @return bool
4248          */
4249         public function isAlwaysKnown() {
4250                 $isKnown = null;
4251
4252                 /**
4253                  * Allows overriding default behavior for determining if a page exists.
4254                  * If $isKnown is kept as null, regular checks happen. If it's
4255                  * a boolean, this value is returned by the isKnown method.
4256                  *
4257                  * @since 1.20
4258                  *
4259                  * @param Title $title
4260                  * @param bool|null $isKnown
4261                  */
4262                 Hooks::run( 'TitleIsAlwaysKnown', [ $this, &$isKnown ] );
4263
4264                 if ( !is_null( $isKnown ) ) {
4265                         return $isKnown;
4266                 }
4267
4268                 if ( $this->isExternal() ) {
4269                         return true;  // any interwiki link might be viewable, for all we know
4270                 }
4271
4272                 switch ( $this->mNamespace ) {
4273                         case NS_MEDIA:
4274                         case NS_FILE:
4275                                 // file exists, possibly in a foreign repo
4276                                 return (bool)wfFindFile( $this );
4277                         case NS_SPECIAL:
4278                                 // valid special page
4279                                 return SpecialPageFactory::exists( $this->getDBkey() );
4280                         case NS_MAIN:
4281                                 // selflink, possibly with fragment
4282                                 return $this->mDbkeyform == '';
4283                         case NS_MEDIAWIKI:
4284                                 // known system message
4285                                 return $this->hasSourceText() !== false;
4286                         default:
4287                                 return false;
4288                 }
4289         }
4290
4291         /**
4292          * Does this title refer to a page that can (or might) be meaningfully
4293          * viewed?  In particular, this function may be used to determine if
4294          * links to the title should be rendered as "bluelinks" (as opposed to
4295          * "redlinks" to non-existent pages).
4296          * Adding something else to this function will cause inconsistency
4297          * since LinkHolderArray calls isAlwaysKnown() and does its own
4298          * page existence check.
4299          *
4300          * @return bool
4301          */
4302         public function isKnown() {
4303                 return $this->isAlwaysKnown() || $this->exists();
4304         }
4305
4306         /**
4307          * Does this page have source text?
4308          *
4309          * @return bool
4310          */
4311         public function hasSourceText() {
4312                 if ( $this->exists() ) {
4313                         return true;
4314                 }
4315
4316                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4317                         // If the page doesn't exist but is a known system message, default
4318                         // message content will be displayed, same for language subpages-
4319                         // Use always content language to avoid loading hundreds of languages
4320                         // to get the link color.
4321                         global $wgContLang;
4322                         list( $name, ) = MessageCache::singleton()->figureMessage(
4323                                 $wgContLang->lcfirst( $this->getText() )
4324                         );
4325                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4326                         return $message->exists();
4327                 }
4328
4329                 return false;
4330         }
4331
4332         /**
4333          * Get the default message text or false if the message doesn't exist
4334          *
4335          * @return string|bool
4336          */
4337         public function getDefaultMessageText() {
4338                 global $wgContLang;
4339
4340                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4341                         return false;
4342                 }
4343
4344                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4345                         $wgContLang->lcfirst( $this->getText() )
4346                 );
4347                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4348
4349                 if ( $message->exists() ) {
4350                         return $message->plain();
4351                 } else {
4352                         return false;
4353                 }
4354         }
4355
4356         /**
4357          * Updates page_touched for this page; called from LinksUpdate.php
4358          *
4359          * @param string $purgeTime [optional] TS_MW timestamp
4360          * @return bool True if the update succeeded
4361          */
4362         public function invalidateCache( $purgeTime = null ) {
4363                 if ( wfReadOnly() ) {
4364                         return false;
4365                 }
4366
4367                 if ( $this->mArticleID === 0 ) {
4368                         return true; // avoid gap locking if we know it's not there
4369                 }
4370
4371                 $method = __METHOD__;
4372                 $dbw = wfGetDB( DB_MASTER );
4373                 $conds = $this->pageCond();
4374                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method, $purgeTime ) {
4375                         $dbTimestamp = $dbw->timestamp( $purgeTime ?: time() );
4376
4377                         $dbw->update(
4378                                 'page',
4379                                 [ 'page_touched' => $dbTimestamp ],
4380                                 $conds + [ 'page_touched < ' . $dbw->addQuotes( $dbTimestamp ) ],
4381                                 $method
4382                         );
4383                 } );
4384
4385                 return true;
4386         }
4387
4388         /**
4389          * Update page_touched timestamps and send CDN purge messages for
4390          * pages linking to this title. May be sent to the job queue depending
4391          * on the number of links. Typically called on create and delete.
4392          */
4393         public function touchLinks() {
4394                 DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'pagelinks' ) );
4395                 if ( $this->getNamespace() == NS_CATEGORY ) {
4396                         DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'categorylinks' ) );
4397                 }
4398         }
4399
4400         /**
4401          * Get the last touched timestamp
4402          *
4403          * @param IDatabase $db Optional db
4404          * @return string Last-touched timestamp
4405          */
4406         public function getTouched( $db = null ) {
4407                 if ( $db === null ) {
4408                         $db = wfGetDB( DB_SLAVE );
4409                 }
4410                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4411                 return $touched;
4412         }
4413
4414         /**
4415          * Get the timestamp when this page was updated since the user last saw it.
4416          *
4417          * @param User $user
4418          * @return string|null
4419          */
4420         public function getNotificationTimestamp( $user = null ) {
4421                 global $wgUser;
4422
4423                 // Assume current user if none given
4424                 if ( !$user ) {
4425                         $user = $wgUser;
4426                 }
4427                 // Check cache first
4428                 $uid = $user->getId();
4429                 if ( !$uid ) {
4430                         return false;
4431                 }
4432                 // avoid isset here, as it'll return false for null entries
4433                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4434                         return $this->mNotificationTimestamp[$uid];
4435                 }
4436                 // Don't cache too much!
4437                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4438                         $this->mNotificationTimestamp = [];
4439                 }
4440
4441                 $watchedItem = WatchedItemStore::getDefaultInstance()->getWatchedItem( $user, $this );
4442                 if ( $watchedItem ) {
4443                         $this->mNotificationTimestamp[$uid] = $watchedItem->getNotificationTimestamp();
4444                 } else {
4445                         $this->mNotificationTimestamp[$uid] = false;
4446                 }
4447
4448                 return $this->mNotificationTimestamp[$uid];
4449         }
4450
4451         /**
4452          * Generate strings used for xml 'id' names in monobook tabs
4453          *
4454          * @param string $prepend Defaults to 'nstab-'
4455          * @return string XML 'id' name
4456          */
4457         public function getNamespaceKey( $prepend = 'nstab-' ) {
4458                 global $wgContLang;
4459                 // Gets the subject namespace if this title
4460                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4461                 // Checks if canonical namespace name exists for namespace
4462                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4463                         // Uses canonical namespace name
4464                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4465                 } else {
4466                         // Uses text of namespace
4467                         $namespaceKey = $this->getSubjectNsText();
4468                 }
4469                 // Makes namespace key lowercase
4470                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4471                 // Uses main
4472                 if ( $namespaceKey == '' ) {
4473                         $namespaceKey = 'main';
4474                 }
4475                 // Changes file to image for backwards compatibility
4476                 if ( $namespaceKey == 'file' ) {
4477                         $namespaceKey = 'image';
4478                 }
4479                 return $prepend . $namespaceKey;
4480         }
4481
4482         /**
4483          * Get all extant redirects to this Title
4484          *
4485          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4486          * @return Title[] Array of Title redirects to this title
4487          */
4488         public function getRedirectsHere( $ns = null ) {
4489                 $redirs = [];
4490
4491                 $dbr = wfGetDB( DB_SLAVE );
4492                 $where = [
4493                         'rd_namespace' => $this->getNamespace(),
4494                         'rd_title' => $this->getDBkey(),
4495                         'rd_from = page_id'
4496                 ];
4497                 if ( $this->isExternal() ) {
4498                         $where['rd_interwiki'] = $this->getInterwiki();
4499                 } else {
4500                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4501                 }
4502                 if ( !is_null( $ns ) ) {
4503                         $where['page_namespace'] = $ns;
4504                 }
4505
4506                 $res = $dbr->select(
4507                         [ 'redirect', 'page' ],
4508                         [ 'page_namespace', 'page_title' ],
4509                         $where,
4510                         __METHOD__
4511                 );
4512
4513                 foreach ( $res as $row ) {
4514                         $redirs[] = self::newFromRow( $row );
4515                 }
4516                 return $redirs;
4517         }
4518
4519         /**
4520          * Check if this Title is a valid redirect target
4521          *
4522          * @return bool
4523          */
4524         public function isValidRedirectTarget() {
4525                 global $wgInvalidRedirectTargets;
4526
4527                 if ( $this->isSpecialPage() ) {
4528                         // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4529                         if ( $this->isSpecial( 'Userlogout' ) ) {
4530                                 return false;
4531                         }
4532
4533                         foreach ( $wgInvalidRedirectTargets as $target ) {
4534                                 if ( $this->isSpecial( $target ) ) {
4535                                         return false;
4536                                 }
4537                         }
4538                 }
4539
4540                 return true;
4541         }
4542
4543         /**
4544          * Get a backlink cache object
4545          *
4546          * @return BacklinkCache
4547          */
4548         public function getBacklinkCache() {
4549                 return BacklinkCache::get( $this );
4550         }
4551
4552         /**
4553          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4554          *
4555          * @return bool
4556          */
4557         public function canUseNoindex() {
4558                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4559
4560                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4561                         ? $wgContentNamespaces
4562                         : $wgExemptFromUserRobotsControl;
4563
4564                 return !in_array( $this->mNamespace, $bannedNamespaces );
4565
4566         }
4567
4568         /**
4569          * Returns the raw sort key to be used for categories, with the specified
4570          * prefix.  This will be fed to Collation::getSortKey() to get a
4571          * binary sortkey that can be used for actual sorting.
4572          *
4573          * @param string $prefix The prefix to be used, specified using
4574          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4575          *   prefix.
4576          * @return string
4577          */
4578         public function getCategorySortkey( $prefix = '' ) {
4579                 $unprefixed = $this->getText();
4580
4581                 // Anything that uses this hook should only depend
4582                 // on the Title object passed in, and should probably
4583                 // tell the users to run updateCollations.php --force
4584                 // in order to re-sort existing category relations.
4585                 Hooks::run( 'GetDefaultSortkey', [ $this, &$unprefixed ] );
4586                 if ( $prefix !== '' ) {
4587                         # Separate with a line feed, so the unprefixed part is only used as
4588                         # a tiebreaker when two pages have the exact same prefix.
4589                         # In UCA, tab is the only character that can sort above LF
4590                         # so we strip both of them from the original prefix.
4591                         $prefix = strtr( $prefix, "\n\t", '  ' );
4592                         return "$prefix\n$unprefixed";
4593                 }
4594                 return $unprefixed;
4595         }
4596
4597         /**
4598          * Returns the page language code saved in the database, if $wgPageLanguageUseDB is set
4599          * to true in LocalSettings.php, otherwise returns false. If there is no language saved in
4600          * the db, it will return NULL.
4601          *
4602          * @return string|null|bool
4603          */
4604         private function getDbPageLanguageCode() {
4605                 global $wgPageLanguageUseDB;
4606
4607                 // check, if the page language could be saved in the database, and if so and
4608                 // the value is not requested already, lookup the page language using LinkCache
4609                 if ( $wgPageLanguageUseDB && $this->mDbPageLanguage === false ) {
4610                         $linkCache = LinkCache::singleton();
4611                         $linkCache->addLinkObj( $this );
4612                         $this->mDbPageLanguage = $linkCache->getGoodLinkFieldObj( $this, 'lang' );
4613                 }
4614
4615                 return $this->mDbPageLanguage;
4616         }
4617
4618         /**
4619          * Get the language in which the content of this page is written in
4620          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4621          * e.g. $wgLang (such as special pages, which are in the user language).
4622          *
4623          * @since 1.18
4624          * @return Language
4625          */
4626         public function getPageLanguage() {
4627                 global $wgLang, $wgLanguageCode;
4628                 if ( $this->isSpecialPage() ) {
4629                         // special pages are in the user language
4630                         return $wgLang;
4631                 }
4632
4633                 // Checking if DB language is set
4634                 $dbPageLanguage = $this->getDbPageLanguageCode();
4635                 if ( $dbPageLanguage ) {
4636                         return wfGetLangObj( $dbPageLanguage );
4637                 }
4638
4639                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4640                         // Note that this may depend on user settings, so the cache should
4641                         // be only per-request.
4642                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4643                         // content to determine the page language!
4644                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4645                         // tests.
4646                         $contentHandler = ContentHandler::getForTitle( $this );
4647                         $langObj = $contentHandler->getPageLanguage( $this );
4648                         $this->mPageLanguage = [ $langObj->getCode(), $wgLanguageCode ];
4649                 } else {
4650                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4651                 }
4652
4653                 return $langObj;
4654         }
4655
4656         /**
4657          * Get the language in which the content of this page is written when
4658          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4659          * e.g. $wgLang (such as special pages, which are in the user language).
4660          *
4661          * @since 1.20
4662          * @return Language
4663          */
4664         public function getPageViewLanguage() {
4665                 global $wgLang;
4666
4667                 if ( $this->isSpecialPage() ) {
4668                         // If the user chooses a variant, the content is actually
4669                         // in a language whose code is the variant code.
4670                         $variant = $wgLang->getPreferredVariant();
4671                         if ( $wgLang->getCode() !== $variant ) {
4672                                 return Language::factory( $variant );
4673                         }
4674
4675                         return $wgLang;
4676                 }
4677
4678                 // Checking if DB language is set
4679                 $dbPageLanguage = $this->getDbPageLanguageCode();
4680                 if ( $dbPageLanguage ) {
4681                         $pageLang = wfGetLangObj( $dbPageLanguage );
4682                         $variant = $pageLang->getPreferredVariant();
4683                         if ( $pageLang->getCode() !== $variant ) {
4684                                 $pageLang = Language::factory( $variant );
4685                         }
4686
4687                         return $pageLang;
4688                 }
4689
4690                 // @note Can't be cached persistently, depends on user settings.
4691                 // @note ContentHandler::getPageViewLanguage() may need to load the
4692                 //   content to determine the page language!
4693                 $contentHandler = ContentHandler::getForTitle( $this );
4694                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4695                 return $pageLang;
4696         }
4697
4698         /**
4699          * Get a list of rendered edit notices for this page.
4700          *
4701          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4702          * they will already be wrapped in paragraphs.
4703          *
4704          * @since 1.21
4705          * @param int $oldid Revision ID that's being edited
4706          * @return array
4707          */
4708         public function getEditNotices( $oldid = 0 ) {
4709                 $notices = [];
4710
4711                 // Optional notice for the entire namespace
4712                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4713                 $msg = wfMessage( $editnotice_ns );
4714                 if ( $msg->exists() ) {
4715                         $html = $msg->parseAsBlock();
4716                         // Edit notices may have complex logic, but output nothing (T91715)
4717                         if ( trim( $html ) !== '' ) {
4718                                 $notices[$editnotice_ns] = Html::rawElement(
4719                                         'div',
4720                                         [ 'class' => [
4721                                                 'mw-editnotice',
4722                                                 'mw-editnotice-namespace',
4723                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4724                                         ] ],
4725                                         $html
4726                                 );
4727                         }
4728                 }
4729
4730                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4731                         // Optional notice for page itself and any parent page
4732                         $parts = explode( '/', $this->getDBkey() );
4733                         $editnotice_base = $editnotice_ns;
4734                         while ( count( $parts ) > 0 ) {
4735                                 $editnotice_base .= '-' . array_shift( $parts );
4736                                 $msg = wfMessage( $editnotice_base );
4737                                 if ( $msg->exists() ) {
4738                                         $html = $msg->parseAsBlock();
4739                                         if ( trim( $html ) !== '' ) {
4740                                                 $notices[$editnotice_base] = Html::rawElement(
4741                                                         'div',
4742                                                         [ 'class' => [
4743                                                                 'mw-editnotice',
4744                                                                 'mw-editnotice-base',
4745                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4746                                                         ] ],
4747                                                         $html
4748                                                 );
4749                                         }
4750                                 }
4751                         }
4752                 } else {
4753                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4754                         $editnoticeText = $editnotice_ns . '-' . strtr( $this->getDBkey(), '/', '-' );
4755                         $msg = wfMessage( $editnoticeText );
4756                         if ( $msg->exists() ) {
4757                                 $html = $msg->parseAsBlock();
4758                                 if ( trim( $html ) !== '' ) {
4759                                         $notices[$editnoticeText] = Html::rawElement(
4760                                                 'div',
4761                                                 [ 'class' => [
4762                                                         'mw-editnotice',
4763                                                         'mw-editnotice-page',
4764                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4765                                                 ] ],
4766                                                 $html
4767                                         );
4768                                 }
4769                         }
4770                 }
4771
4772                 Hooks::run( 'TitleGetEditNotices', [ $this, $oldid, &$notices ] );
4773                 return $notices;
4774         }
4775
4776         /**
4777          * @return array
4778          */
4779         public function __sleep() {
4780                 return [
4781                         'mNamespace',
4782                         'mDbkeyform',
4783                         'mFragment',
4784                         'mInterwiki',
4785                         'mLocalInterwiki',
4786                         'mUserCaseDBKey',
4787                         'mDefaultNamespace',
4788                 ];
4789         }
4790
4791         public function __wakeup() {
4792                 $this->mArticleID = ( $this->mNamespace >= 0 ) ? -1 : 0;
4793                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
4794                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
4795         }
4796
4797 }