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 use MediaWiki\Interwiki\InterwikiLookup;
  26 use MediaWiki\MediaWikiServices;
  27
  28 /**
  29  * Represents a title within MediaWiki.
  30  * Optionally may contain an interwiki designation or namespace.
  31  * @note This class can fetch various kinds of data from the database;
  32  *       however, it does so inefficiently.
  33  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  34  *       and does not rely on global state or the database.
  35  */
  36 class Title implements LinkTarget {
  37         /** @var HashBagOStuff */
  38         static private $titleCache = null;
  39
  40         /**
  41          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  42          * commonly used titles. On a batch operation this can become a memory leak
  43          * if not bounded. After hitting this many titles reset the cache.
  44          */
  45         const CACHE_MAX = 1000;
  46
  47         /**
  48          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  49          * to use the master DB
  50          */
  51         const GAID_FOR_UPDATE = 1;
  52
  53         /**
  54          * @name Private member variables
  55          * Please use the accessor functions instead.
  56          * @private
  57          */
  58         // @{
  59
  60         /** @var string Text form (spaces not underscores) of the main part */
  61         public $mTextform = '';
  62
  63         /** @var string URL-encoded form of the main part */
  64         public $mUrlform = '';
  65
  66         /** @var string Main part with underscores */
  67         public $mDbkeyform = '';
  68
  69         /** @var string Database key with the initial letter in the case specified by the user */
  70         protected $mUserCaseDBKey;
  71
  72         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  73         public $mNamespace = NS_MAIN;
  74
  75         /** @var string Interwiki prefix */
  76         public $mInterwiki = '';
  77
  78         /** @var bool Was this Title created from a string with a local interwiki prefix? */
  79         private $mLocalInterwiki = false;
  80
  81         /** @var string Title fragment (i.e. the bit after the #) */
  82         public $mFragment = '';
  83
  84         /** @var int Article ID, fetched from the link cache on demand */
  85         public $mArticleID = -1;
  86
  87         /** @var bool|int ID of most recent revision */
  88         protected $mLatestID = false;
  89
  90         /**
  91          * @var bool|string ID of the page's content model, i.e. one of the
  92          *   CONTENT_MODEL_XXX constants
  93          */
  94         public $mContentModel = false;
  95
  96         /** @var int Estimated number of revisions; null of not loaded */
  97         private $mEstimateRevisions;
  98
  99         /** @var array Array of groups allowed to edit this article */
 100         public $mRestrictions = [];
 101
 102         /** @var string|bool */
 103         protected $mOldRestrictions = false;
 104
 105         /** @var bool Cascade restrictions on this page to included templates and images? */
 106         public $mCascadeRestriction;
 107
 108         /** Caching the results of getCascadeProtectionSources */
 109         public $mCascadingRestrictions;
 110
 111         /** @var array When do the restrictions on this page expire? */
 112         protected $mRestrictionsExpiry = [];
 113
 114         /** @var bool Are cascading restrictions in effect on this page? */
 115         protected $mHasCascadingRestrictions;
 116
 117         /** @var array Where are the cascading restrictions coming from on this page? */
 118         public $mCascadeSources;
 119
 120         /** @var bool Boolean for initialisation on demand */
 121         public $mRestrictionsLoaded = false;
 122
 123         /** @var string Text form including namespace/interwiki, initialised on demand */
 124         protected $mPrefixedText = null;
 125
 126         /** @var mixed Cached value for getTitleProtection (create protection) */
 127         public $mTitleProtection;
 128
 129         /**
 130          * @var int Namespace index when there is no namespace. Don't change the
 131          *   following default, NS_MAIN is hardcoded in several places. See bug 696.
 132          *   Zero except in {{transclusion}} tags.
 133          */
 134         public $mDefaultNamespace = NS_MAIN;
 135
 136         /** @var int The page length, 0 for special pages */
 137         protected $mLength = -1;
 138
 139         /** @var null Is the article at this title a redirect? */
 140         public $mRedirect = null;
 141
 142         /** @var array Associative array of user ID -> timestamp/false */
 143         private $mNotificationTimestamp = [];
 144
 145         /** @var bool Whether a page has any subpages */
 146         private $mHasSubpages;
 147
 148         /** @var bool The (string) language code of the page's language and content code. */
 149         private $mPageLanguage = false;
 150
 151         /** @var string|bool|null The page language code from the database, null if not saved in
 152          * the database or false if not loaded, yet. */
 153         private $mDbPageLanguage = false;
 154
 155         /** @var TitleValue A corresponding TitleValue object */
 156         private $mTitleValue = null;
 157
 158         /** @var bool Would deleting this page be a big deletion? */
 159         private $mIsBigDeletion = null;
 160         // @}
 161
 162         /**
 163          * B/C kludge: provide a TitleParser for use by Title.
 164          * Ideally, Title would have no methods that need this.
 165          * Avoid usage of this singleton by using TitleValue
 166          * and the associated services when possible.
 167          *
 168          * @return TitleFormatter
 169          */
 170         private static function getTitleFormatter() {
 171                 return MediaWikiServices::getInstance()->getTitleFormatter();
 172         }
 173
 174         /**
 175          * B/C kludge: provide an InterwikiLookup for use by Title.
 176          * Ideally, Title would have no methods that need this.
 177          * Avoid usage of this singleton by using TitleValue
 178          * and the associated services when possible.
 179          *
 180          * @return InterwikiLookup
 181          */
 182         private static function getInterwikiLookup() {
 183                 return MediaWikiServices::getInstance()->getInterwikiLookup();
 184         }
 185
 186         /**
 187          * @access protected
 188          */
 189         function __construct() {
 190         }
 191
 192         /**
 193          * Create a new Title from a prefixed DB key
 194          *
 195          * @param string $key The database key, which has underscores
 196          *      instead of spaces, possibly including namespace and
 197          *      interwiki prefixes
 198          * @return Title|null Title, or null on an error
 199          */
 200         public static function newFromDBkey( $key ) {
 201                 $t = new Title();
 202                 $t->mDbkeyform = $key;
 203
 204                 try {
 205                         $t->secureAndSplit();
 206                         return $t;
 207                 } catch ( MalformedTitleException $ex ) {
 208                         return null;
 209                 }
 210         }
 211
 212         /**
 213          * Create a new Title from a TitleValue
 214          *
 215          * @param TitleValue $titleValue Assumed to be safe.
 216          *
 217          * @return Title
 218          */
 219         public static function newFromTitleValue( TitleValue $titleValue ) {
 220                 return self::newFromLinkTarget( $titleValue );
 221         }
 222
 223         /**
 224          * Create a new Title from a LinkTarget
 225          *
 226          * @param LinkTarget $linkTarget Assumed to be safe.
 227          *
 228          * @return Title
 229          */
 230         public static function newFromLinkTarget( LinkTarget $linkTarget ) {
 231                 if ( $linkTarget instanceof Title ) {
 232                         // Special case if it's already a Title object
 233                         return $linkTarget;
 234                 }
 235                 return self::makeTitle(
 236                         $linkTarget->getNamespace(),
 237                         $linkTarget->getText(),
 238                         $linkTarget->getFragment(),
 239                         $linkTarget->getInterwiki()
 240                 );
 241         }
 242
 243         /**
 244          * Create a new Title from text, such as what one would find in a link. De-
 245          * codes any HTML entities in the text.
 246          *
 247          * @param string|int|null $text The link text; spaces, prefixes, and an
 248          *   initial ':' indicating the main namespace are accepted.
 249          * @param int $defaultNamespace The namespace to use if none is specified
 250          *   by a prefix.  If you want to force a specific namespace even if
 251          *   $text might begin with a namespace prefix, use makeTitle() or
 252          *   makeTitleSafe().
 253          * @throws InvalidArgumentException
 254          * @return Title|null Title or null on an error.
 255          */
 256         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 257                 // DWIM: Integers can be passed in here when page titles are used as array keys.
 258                 if ( $text !== null && !is_string( $text ) && !is_int( $text ) ) {
 259                         throw new InvalidArgumentException( '$text must be a string.' );
 260                 }
 261                 if ( $text === null ) {
 262                         return null;
 263                 }
 264
 265                 try {
 266                         return Title::newFromTextThrow( strval( $text ), $defaultNamespace );
 267                 } catch ( MalformedTitleException $ex ) {
 268                         return null;
 269                 }
 270         }
 271
 272         /**
 273          * Like Title::newFromText(), but throws MalformedTitleException when the title is invalid,
 274          * rather than returning null.
 275          *
 276          * The exception subclasses encode detailed information about why the title is invalid.
 277          *
 278          * @see Title::newFromText
 279          *
 280          * @since 1.25
 281          * @param string $text Title text to check
 282          * @param int $defaultNamespace
 283          * @throws MalformedTitleException If the title is invalid
 284          * @return Title
 285          */
 286         public static function newFromTextThrow( $text, $defaultNamespace = NS_MAIN ) {
 287                 if ( is_object( $text ) ) {
 288                         throw new MWException( '$text must be a string, given an object' );
 289                 }
 290
 291                 $titleCache = self::getTitleCache();
 292
 293                 // Wiki pages often contain multiple links to the same page.
 294                 // Title normalization and parsing can become expensive on pages with many
 295                 // links, so we can save a little time by caching them.
 296                 // In theory these are value objects and won't get changed...
 297                 if ( $defaultNamespace == NS_MAIN ) {
 298                         $t = $titleCache->get( $text );
 299                         if ( $t ) {
 300                                 return $t;
 301                         }
 302                 }
 303
 304                 // Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 305                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 306
 307                 $t = new Title();
 308                 $t->mDbkeyform = strtr( $filteredText, ' ', '_' );
 309                 $t->mDefaultNamespace = intval( $defaultNamespace );
 310
 311                 $t->secureAndSplit();
 312                 if ( $defaultNamespace == NS_MAIN ) {
 313                         $titleCache->set( $text, $t );
 314                 }
 315                 return $t;
 316         }
 317
 318         /**
 319          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 320          *
 321          * Example of wrong and broken code:
 322          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 323          *
 324          * Example of right code:
 325          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 326          *
 327          * Create a new Title from URL-encoded text. Ensures that
 328          * the given title's length does not exceed the maximum.
 329          *
 330          * @param string $url The title, as might be taken from a URL
 331          * @return Title|null The new object, or null on an error
 332          */
 333         public static function newFromURL( $url ) {
 334                 $t = new Title();
 335
 336                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 337                 # but some URLs used it as a space replacement and they still come
 338                 # from some external search tools.
 339                 if ( strpos( self::legalChars(), '+' ) === false ) {
 340                         $url = strtr( $url, '+', ' ' );
 341                 }
 342
 343                 $t->mDbkeyform = strtr( $url, ' ', '_' );
 344
 345                 try {
 346                         $t->secureAndSplit();
 347                         return $t;
 348                 } catch ( MalformedTitleException $ex ) {
 349                         return null;
 350                 }
 351         }
 352
 353         /**
 354          * @return HashBagOStuff
 355          */
 356         private static function getTitleCache() {
 357                 if ( self::$titleCache == null ) {
 358                         self::$titleCache = new HashBagOStuff( [ 'maxKeys' => self::CACHE_MAX ] );
 359                 }
 360                 return self::$titleCache;
 361         }
 362
 363         /**
 364          * Returns a list of fields that are to be selected for initializing Title
 365          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 366          * whether to include page_content_model.
 367          *
 368          * @return array
 369          */
 370         protected static function getSelectFields() {
 371                 global $wgContentHandlerUseDB, $wgPageLanguageUseDB;
 372
 373                 $fields = [
 374                         'page_namespace', 'page_title', 'page_id',
 375                         'page_len', 'page_is_redirect', 'page_latest',
 376                 ];
 377
 378                 if ( $wgContentHandlerUseDB ) {
 379                         $fields[] = 'page_content_model';
 380                 }
 381
 382                 if ( $wgPageLanguageUseDB ) {
 383                         $fields[] = 'page_lang';
 384                 }
 385
 386                 return $fields;
 387         }
 388
 389         /**
 390          * Create a new Title from an article ID
 391          *
 392          * @param int $id The page_id corresponding to the Title to create
 393          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 394          * @return Title|null The new object, or null on an error
 395          */
 396         public static function newFromID( $id, $flags = 0 ) {
 397                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 398                 $row = $db->selectRow(
 399                         'page',
 400                         self::getSelectFields(),
 401                         [ 'page_id' => $id ],
 402                         __METHOD__
 403                 );
 404                 if ( $row !== false ) {
 405                         $title = Title::newFromRow( $row );
 406                 } else {
 407                         $title = null;
 408                 }
 409                 return $title;
 410         }
 411
 412         /**
 413          * Make an array of titles from an array of IDs
 414          *
 415          * @param int[] $ids Array of IDs
 416          * @return Title[] Array of Titles
 417          */
 418         public static function newFromIDs( $ids ) {
 419                 if ( !count( $ids ) ) {
 420                         return [];
 421                 }
 422                 $dbr = wfGetDB( DB_SLAVE );
 423
 424                 $res = $dbr->select(
 425                         'page',
 426                         self::getSelectFields(),
 427                         [ 'page_id' => $ids ],
 428                         __METHOD__
 429                 );
 430
 431                 $titles = [];
 432                 foreach ( $res as $row ) {
 433                         $titles[] = Title::newFromRow( $row );
 434                 }
 435                 return $titles;
 436         }
 437
 438         /**
 439          * Make a Title object from a DB row
 440          *
 441          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 442          * @return Title Corresponding Title
 443          */
 444         public static function newFromRow( $row ) {
 445                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 446                 $t->loadFromRow( $row );
 447                 return $t;
 448         }
 449
 450         /**
 451          * Load Title object fields from a DB row.
 452          * If false is given, the title will be treated as non-existing.
 453          *
 454          * @param stdClass|bool $row Database row
 455          */
 456         public function loadFromRow( $row ) {
 457                 if ( $row ) { // page found
 458                         if ( isset( $row->page_id ) ) {
 459                                 $this->mArticleID = (int)$row->page_id;
 460                         }
 461                         if ( isset( $row->page_len ) ) {
 462                                 $this->mLength = (int)$row->page_len;
 463                         }
 464                         if ( isset( $row->page_is_redirect ) ) {
 465                                 $this->mRedirect = (bool)$row->page_is_redirect;
 466                         }
 467                         if ( isset( $row->page_latest ) ) {
 468                                 $this->mLatestID = (int)$row->page_latest;
 469                         }
 470                         if ( isset( $row->page_content_model ) ) {
 471                                 $this->mContentModel = strval( $row->page_content_model );
 472                         } else {
 473                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 474                         }
 475                         if ( isset( $row->page_lang ) ) {
 476                                 $this->mDbPageLanguage = (string)$row->page_lang;
 477                         }
 478                         if ( isset( $row->page_restrictions ) ) {
 479                                 $this->mOldRestrictions = $row->page_restrictions;
 480                         }
 481                 } else { // page not found
 482                         $this->mArticleID = 0;
 483                         $this->mLength = 0;
 484                         $this->mRedirect = false;
 485                         $this->mLatestID = 0;
 486                         $this->mContentModel = false; # initialized lazily in getContentModel()
 487                 }
 488         }
 489
 490         /**
 491          * Create a new Title from a namespace index and a DB key.
 492          * It's assumed that $ns and $title are *valid*, for instance when
 493          * they came directly from the database or a special page name.
 494          * For convenience, spaces are converted to underscores so that
 495          * eg user_text fields can be used directly.
 496          *
 497          * @param int $ns The namespace of the article
 498          * @param string $title The unprefixed database key form
 499          * @param string $fragment The link fragment (after the "#")
 500          * @param string $interwiki The interwiki prefix
 501          * @return Title The new object
 502          */
 503         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 504                 $t = new Title();
 505                 $t->mInterwiki = $interwiki;
 506                 $t->mFragment = $fragment;
 507                 $t->mNamespace = $ns = intval( $ns );
 508                 $t->mDbkeyform = strtr( $title, ' ', '_' );
 509                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 510                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 511                 $t->mTextform = strtr( $title, '_', ' ' );
 512                 $t->mContentModel = false; # initialized lazily in getContentModel()
 513                 return $t;
 514         }
 515
 516         /**
 517          * Create a new Title from a namespace index and a DB key.
 518          * The parameters will be checked for validity, which is a bit slower
 519          * than makeTitle() but safer for user-provided data.
 520          *
 521          * @param int $ns The namespace of the article
 522          * @param string $title Database key form
 523          * @param string $fragment The link fragment (after the "#")
 524          * @param string $interwiki Interwiki prefix
 525          * @return Title|null The new object, or null on an error
 526          */
 527         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 528                 if ( !MWNamespace::exists( $ns ) ) {
 529                         return null;
 530                 }
 531
 532                 $t = new Title();
 533                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 534
 535                 try {
 536                         $t->secureAndSplit();
 537                         return $t;
 538                 } catch ( MalformedTitleException $ex ) {
 539                         return null;
 540                 }
 541         }
 542
 543         /**
 544          * Create a new Title for the Main Page
 545          *
 546          * @return Title The new object
 547          */
 548         public static function newMainPage() {
 549                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 550                 // Don't give fatal errors if the message is broken
 551                 if ( !$title ) {
 552                         $title = Title::newFromText( 'Main Page' );
 553                 }
 554                 return $title;
 555         }
 556
 557         /**
 558          * Get the prefixed DB key associated with an ID
 559          *
 560          * @param int $id The page_id of the article
 561          * @return Title|null An object representing the article, or null if no such article was found
 562          */
 563         public static function nameOf( $id ) {
 564                 $dbr = wfGetDB( DB_SLAVE );
 565
 566                 $s = $dbr->selectRow(
 567                         'page',
 568                         [ 'page_namespace', 'page_title' ],
 569                         [ 'page_id' => $id ],
 570                         __METHOD__
 571                 );
 572                 if ( $s === false ) {
 573                         return null;
 574                 }
 575
 576                 $n = self::makeName( $s->page_namespace, $s->page_title );
 577                 return $n;
 578         }
 579
 580         /**
 581          * Get a regex character class describing the legal characters in a link
 582          *
 583          * @return string The list of characters, not delimited
 584          */
 585         public static function legalChars() {
 586                 global $wgLegalTitleChars;
 587                 return $wgLegalTitleChars;
 588         }
 589
 590         /**
 591          * Returns a simple regex that will match on characters and sequences invalid in titles.
 592          * Note that this doesn't pick up many things that could be wrong with titles, but that
 593          * replacing this regex with something valid will make many titles valid.
 594          *
 595          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 596          *
 597          * @return string Regex string
 598          */
 599         static function getTitleInvalidRegex() {
 600                 wfDeprecated( __METHOD__, '1.25' );
 601                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 602         }
 603
 604         /**
 605          * Utility method for converting a character sequence from bytes to Unicode.
 606          *
 607          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 608          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 609          *
 610          * @param string $byteClass
 611          * @return string
 612          */
 613         public static function convertByteClassToUnicodeClass( $byteClass ) {
 614                 $length = strlen( $byteClass );
 615                 // Input token queue
 616                 $x0 = $x1 = $x2 = '';
 617                 // Decoded queue
 618                 $d0 = $d1 = $d2 = '';
 619                 // Decoded integer codepoints
 620                 $ord0 = $ord1 = $ord2 = 0;
 621                 // Re-encoded queue
 622                 $r0 = $r1 = $r2 = '';
 623                 // Output
 624                 $out = '';
 625                 // Flags
 626                 $allowUnicode = false;
 627                 for ( $pos = 0; $pos < $length; $pos++ ) {
 628                         // Shift the queues down
 629                         $x2 = $x1;
 630                         $x1 = $x0;
 631                         $d2 = $d1;
 632                         $d1 = $d0;
 633                         $ord2 = $ord1;
 634                         $ord1 = $ord0;
 635                         $r2 = $r1;
 636                         $r1 = $r0;
 637                         // Load the current input token and decoded values
 638                         $inChar = $byteClass[$pos];
 639                         if ( $inChar == '\\' ) {
 640                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 641                                         $x0 = $inChar . $m[0];
 642                                         $d0 = chr( hexdec( $m[1] ) );
 643                                         $pos += strlen( $m[0] );
 644                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 645                                         $x0 = $inChar . $m[0];
 646                                         $d0 = chr( octdec( $m[0] ) );
 647                                         $pos += strlen( $m[0] );
 648                                 } elseif ( $pos + 1 >= $length ) {
 649                                         $x0 = $d0 = '\\';
 650                                 } else {
 651                                         $d0 = $byteClass[$pos + 1];
 652                                         $x0 = $inChar . $d0;
 653                                         $pos += 1;
 654                                 }
 655                         } else {
 656                                 $x0 = $d0 = $inChar;
 657                         }
 658                         $ord0 = ord( $d0 );
 659                         // Load the current re-encoded value
 660                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 661                                 $r0 = sprintf( '\x%02x', $ord0 );
 662                         } elseif ( $ord0 >= 0x80 ) {
 663                                 // Allow unicode if a single high-bit character appears
 664                                 $r0 = sprintf( '\x%02x', $ord0 );
 665                                 $allowUnicode = true;
 666                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 667                                 $r0 = '\\' . $d0;
 668                         } else {
 669                                 $r0 = $d0;
 670                         }
 671                         // Do the output
 672                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 673                                 // Range
 674                                 if ( $ord2 > $ord0 ) {
 675                                         // Empty range
 676                                 } elseif ( $ord0 >= 0x80 ) {
 677                                         // Unicode range
 678                                         $allowUnicode = true;
 679                                         if ( $ord2 < 0x80 ) {
 680                                                 // Keep the non-unicode section of the range
 681                                                 $out .= "$r2-\\x7F";
 682                                         }
 683                                 } else {
 684                                         // Normal range
 685                                         $out .= "$r2-$r0";
 686                                 }
 687                                 // Reset state to the initial value
 688                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 689                         } elseif ( $ord2 < 0x80 ) {
 690                                 // ASCII character
 691                                 $out .= $r2;
 692                         }
 693                 }
 694                 if ( $ord1 < 0x80 ) {
 695                         $out .= $r1;
 696                 }
 697                 if ( $ord0 < 0x80 ) {
 698                         $out .= $r0;
 699                 }
 700                 if ( $allowUnicode ) {
 701                         $out .= '\u0080-\uFFFF';
 702                 }
 703                 return $out;
 704         }
 705
 706         /**
 707          * Make a prefixed DB key from a DB key and a namespace index
 708          *
 709          * @param int $ns Numerical representation of the namespace
 710          * @param string $title The DB key form the title
 711          * @param string $fragment The link fragment (after the "#")
 712          * @param string $interwiki The interwiki prefix
 713          * @param bool $canonicalNamespace If true, use the canonical name for
 714          *   $ns instead of the localized version.
 715          * @return string The prefixed form of the title
 716          */
 717         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 718                 $canonicalNamespace = false
 719         ) {
 720                 global $wgContLang;
 721
 722                 if ( $canonicalNamespace ) {
 723                         $namespace = MWNamespace::getCanonicalName( $ns );
 724                 } else {
 725                         $namespace = $wgContLang->getNsText( $ns );
 726                 }
 727                 $name = $namespace == '' ? $title : "$namespace:$title";
 728                 if ( strval( $interwiki ) != '' ) {
 729                         $name = "$interwiki:$name";
 730                 }
 731                 if ( strval( $fragment ) != '' ) {
 732                         $name .= '#' . $fragment;
 733                 }
 734                 return $name;
 735         }
 736
 737         /**
 738          * Escape a text fragment, say from a link, for a URL
 739          *
 740          * @param string $fragment Containing a URL or link fragment (after the "#")
 741          * @return string Escaped string
 742          */
 743         static function escapeFragmentForURL( $fragment ) {
 744                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 745                 # fragments appear not to work in IE (at least up to 7) or in at least
 746                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 747                 # to care if they aren't encoded.
 748                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 749         }
 750
 751         /**
 752          * Callback for usort() to do title sorts by (namespace, title)
 753          *
 754          * @param Title $a
 755          * @param Title $b
 756          *
 757          * @return int Result of string comparison, or namespace comparison
 758          */
 759         public static function compare( $a, $b ) {
 760                 if ( $a->getNamespace() == $b->getNamespace() ) {
 761                         return strcmp( $a->getText(), $b->getText() );
 762                 } else {
 763                         return $a->getNamespace() - $b->getNamespace();
 764                 }
 765         }
 766
 767         /**
 768          * Determine whether the object refers to a page within
 769          * this project (either this wiki or a wiki with a local
 770          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 771          *
 772          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 773          */
 774         public function isLocal() {
 775                 if ( $this->isExternal() ) {
 776                         $iw = self::getInterwikiLookup()->fetch( $this->mInterwiki );
 777                         if ( $iw ) {
 778                                 return $iw->isLocal();
 779                         }
 780                 }
 781                 return true;
 782         }
 783
 784         /**
 785          * Is this Title interwiki?
 786          *
 787          * @return bool
 788          */
 789         public function isExternal() {
 790                 return $this->mInterwiki !== '';
 791         }
 792
 793         /**
 794          * Get the interwiki prefix
 795          *
 796          * Use Title::isExternal to check if a interwiki is set
 797          *
 798          * @return string Interwiki prefix
 799          */
 800         public function getInterwiki() {
 801                 return $this->mInterwiki;
 802         }
 803
 804         /**
 805          * Was this a local interwiki link?
 806          *
 807          * @return bool
 808          */
 809         public function wasLocalInterwiki() {
 810                 return $this->mLocalInterwiki;
 811         }
 812
 813         /**
 814          * Determine whether the object refers to a page within
 815          * this project and is transcludable.
 816          *
 817          * @return bool True if this is transcludable
 818          */
 819         public function isTrans() {
 820                 if ( !$this->isExternal() ) {
 821                         return false;
 822                 }
 823
 824                 return self::getInterwikiLookup()->fetch( $this->mInterwiki )->isTranscludable();
 825         }
 826
 827         /**
 828          * Returns the DB name of the distant wiki which owns the object.
 829          *
 830          * @return string The DB name
 831          */
 832         public function getTransWikiID() {
 833                 if ( !$this->isExternal() ) {
 834                         return false;
 835                 }
 836
 837                 return self::getInterwikiLookup()->fetch( $this->mInterwiki )->getWikiID();
 838         }
 839
 840         /**
 841          * Get a TitleValue object representing this Title.
 842          *
 843          * @note Not all valid Titles have a corresponding valid TitleValue
 844          * (e.g. TitleValues cannot represent page-local links that have a
 845          * fragment but no title text).
 846          *
 847          * @return TitleValue|null
 848          */
 849         public function getTitleValue() {
 850                 if ( $this->mTitleValue === null ) {
 851                         try {
 852                                 $this->mTitleValue = new TitleValue(
 853                                         $this->getNamespace(),
 854                                         $this->getDBkey(),
 855                                         $this->getFragment(),
 856                                         $this->getInterwiki()
 857                                 );
 858                         } catch ( InvalidArgumentException $ex ) {
 859                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 860                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 861                         }
 862                 }
 863
 864                 return $this->mTitleValue;
 865         }
 866
 867         /**
 868          * Get the text form (spaces not underscores) of the main part
 869          *
 870          * @return string Main part of the title
 871          */
 872         public function getText() {
 873                 return $this->mTextform;
 874         }
 875
 876         /**
 877          * Get the URL-encoded form of the main part
 878          *
 879          * @return string Main part of the title, URL-encoded
 880          */
 881         public function getPartialURL() {
 882                 return $this->mUrlform;
 883         }
 884
 885         /**
 886          * Get the main part with underscores
 887          *
 888          * @return string Main part of the title, with underscores
 889          */
 890         public function getDBkey() {
 891                 return $this->mDbkeyform;
 892         }
 893
 894         /**
 895          * Get the DB key with the initial letter case as specified by the user
 896          *
 897          * @return string DB key
 898          */
 899         function getUserCaseDBKey() {
 900                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 901                         return $this->mUserCaseDBKey;
 902                 } else {
 903                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 904                         return $this->mDbkeyform;
 905                 }
 906         }
 907
 908         /**
 909          * Get the namespace index, i.e. one of the NS_xxxx constants.
 910          *
 911          * @return int Namespace index
 912          */
 913         public function getNamespace() {
 914                 return $this->mNamespace;
 915         }
 916
 917         /**
 918          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 919          *
 920          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 921          * @return string Content model id
 922          */
 923         public function getContentModel( $flags = 0 ) {
 924                 if ( ( !$this->mContentModel || $flags === Title::GAID_FOR_UPDATE ) &&
 925                         $this->getArticleID( $flags )
 926                 ) {
 927                         $linkCache = LinkCache::singleton();
 928                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 929                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 930                 }
 931
 932                 if ( !$this->mContentModel ) {
 933                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 934                 }
 935
 936                 return $this->mContentModel;
 937         }
 938
 939         /**
 940          * Convenience method for checking a title's content model name
 941          *
 942          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 943          * @return bool True if $this->getContentModel() == $id
 944          */
 945         public function hasContentModel( $id ) {
 946                 return $this->getContentModel() == $id;
 947         }
 948
 949         /**
 950          * Get the namespace text
 951          *
 952          * @return string Namespace text
 953          */
 954         public function getNsText() {
 955                 if ( $this->isExternal() ) {
 956                         // This probably shouldn't even happen,
 957                         // but for interwiki transclusion it sometimes does.
 958                         // Use the canonical namespaces if possible to try to
 959                         // resolve a foreign namespace.
 960                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 961                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 962                         }
 963                 }
 964
 965                 try {
 966                         $formatter = self::getTitleFormatter();
 967                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 968                 } catch ( InvalidArgumentException $ex ) {
 969                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 970                         return false;
 971                 }
 972         }
 973
 974         /**
 975          * Get the namespace text of the subject (rather than talk) page
 976          *
 977          * @return string Namespace text
 978          */
 979         public function getSubjectNsText() {
 980                 global $wgContLang;
 981                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 982         }
 983
 984         /**
 985          * Get the namespace text of the talk page
 986          *
 987          * @return string Namespace text
 988          */
 989         public function getTalkNsText() {
 990                 global $wgContLang;
 991                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
 992         }
 993
 994         /**
 995          * Could this title have a corresponding talk page?
 996          *
 997          * @return bool
 998          */
 999         public function canTalk() {
1000                 return MWNamespace::canTalk( $this->mNamespace );
1001         }
1002
1003         /**
1004          * Is this in a namespace that allows actual pages?
1005          *
1006          * @return bool
1007          */
1008         public function canExist() {
1009                 return $this->mNamespace >= NS_MAIN;
1010         }
1011
1012         /**
1013          * Can this title be added to a user's watchlist?
1014          *
1015          * @return bool
1016          */
1017         public function isWatchable() {
1018                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1019         }
1020
1021         /**
1022          * Returns true if this is a special page.
1023          *
1024          * @return bool
1025          */
1026         public function isSpecialPage() {
1027                 return $this->getNamespace() == NS_SPECIAL;
1028         }
1029
1030         /**
1031          * Returns true if this title resolves to the named special page
1032          *
1033          * @param string $name The special page name
1034          * @return bool
1035          */
1036         public function isSpecial( $name ) {
1037                 if ( $this->isSpecialPage() ) {
1038                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1039                         if ( $name == $thisName ) {
1040                                 return true;
1041                         }
1042                 }
1043                 return false;
1044         }
1045
1046         /**
1047          * If the Title refers to a special page alias which is not the local default, resolve
1048          * the alias, and localise the name as necessary.  Otherwise, return $this
1049          *
1050          * @return Title
1051          */
1052         public function fixSpecialName() {
1053                 if ( $this->isSpecialPage() ) {
1054                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1055                         if ( $canonicalName ) {
1056                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1057                                 if ( $localName != $this->mDbkeyform ) {
1058                                         return Title::makeTitle( NS_SPECIAL, $localName );
1059                                 }
1060                         }
1061                 }
1062                 return $this;
1063         }
1064
1065         /**
1066          * Returns true if the title is inside the specified namespace.
1067          *
1068          * Please make use of this instead of comparing to getNamespace()
1069          * This function is much more resistant to changes we may make
1070          * to namespaces than code that makes direct comparisons.
1071          * @param int $ns The namespace
1072          * @return bool
1073          * @since 1.19
1074          */
1075         public function inNamespace( $ns ) {
1076                 return MWNamespace::equals( $this->getNamespace(), $ns );
1077         }
1078
1079         /**
1080          * Returns true if the title is inside one of the specified namespaces.
1081          *
1082          * @param int $namespaces,... The namespaces to check for
1083          * @return bool
1084          * @since 1.19
1085          */
1086         public function inNamespaces( /* ... */ ) {
1087                 $namespaces = func_get_args();
1088                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1089                         $namespaces = $namespaces[0];
1090                 }
1091
1092                 foreach ( $namespaces as $ns ) {
1093                         if ( $this->inNamespace( $ns ) ) {
1094                                 return true;
1095                         }
1096                 }
1097
1098                 return false;
1099         }
1100
1101         /**
1102          * Returns true if the title has the same subject namespace as the
1103          * namespace specified.
1104          * For example this method will take NS_USER and return true if namespace
1105          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1106          * as their subject namespace.
1107          *
1108          * This is MUCH simpler than individually testing for equivalence
1109          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1110          * @since 1.19
1111          * @param int $ns
1112          * @return bool
1113          */
1114         public function hasSubjectNamespace( $ns ) {
1115                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1116         }
1117
1118         /**
1119          * Is this Title in a namespace which contains content?
1120          * In other words, is this a content page, for the purposes of calculating
1121          * statistics, etc?
1122          *
1123          * @return bool
1124          */
1125         public function isContentPage() {
1126                 return MWNamespace::isContent( $this->getNamespace() );
1127         }
1128
1129         /**
1130          * Would anybody with sufficient privileges be able to move this page?
1131          * Some pages just aren't movable.
1132          *
1133          * @return bool
1134          */
1135         public function isMovable() {
1136                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1137                         // Interwiki title or immovable namespace. Hooks don't get to override here
1138                         return false;
1139                 }
1140
1141                 $result = true;
1142                 Hooks::run( 'TitleIsMovable', [ $this, &$result ] );
1143                 return $result;
1144         }
1145
1146         /**
1147          * Is this the mainpage?
1148          * @note Title::newFromText seems to be sufficiently optimized by the title
1149          * cache that we don't need to over-optimize by doing direct comparisons and
1150          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1151          * ends up reporting something differently than $title->isMainPage();
1152          *
1153          * @since 1.18
1154          * @return bool
1155          */
1156         public function isMainPage() {
1157                 return $this->equals( Title::newMainPage() );
1158         }
1159
1160         /**
1161          * Is this a subpage?
1162          *
1163          * @return bool
1164          */
1165         public function isSubpage() {
1166                 return MWNamespace::hasSubpages( $this->mNamespace )
1167                         ? strpos( $this->getText(), '/' ) !== false
1168                         : false;
1169         }
1170
1171         /**
1172          * Is this a conversion table for the LanguageConverter?
1173          *
1174          * @return bool
1175          */
1176         public function isConversionTable() {
1177                 // @todo ConversionTable should become a separate content model.
1178
1179                 return $this->getNamespace() == NS_MEDIAWIKI &&
1180                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1181         }
1182
1183         /**
1184          * Does that page contain wikitext, or it is JS, CSS or whatever?
1185          *
1186          * @return bool
1187          */
1188         public function isWikitextPage() {
1189                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1190         }
1191
1192         /**
1193          * Could this page contain custom CSS or JavaScript for the global UI.
1194          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1195          * or CONTENT_MODEL_JAVASCRIPT.
1196          *
1197          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1198          * for that!
1199          *
1200          * Note that this method should not return true for pages that contain and
1201          * show "inactive" CSS or JS.
1202          *
1203          * @return bool
1204          * @todo FIXME: Rename to isSiteConfigPage() and remove deprecated hook
1205          */
1206         public function isCssOrJsPage() {
1207                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1208                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1209                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1210
1211                 # @note This hook is also called in ContentHandler::getDefaultModel.
1212                 #   It's called here again to make sure hook functions can force this
1213                 #   method to return true even outside the MediaWiki namespace.
1214
1215                 Hooks::run( 'TitleIsCssOrJsPage', [ $this, &$isCssOrJsPage ], '1.25' );
1216
1217                 return $isCssOrJsPage;
1218         }
1219
1220         /**
1221          * Is this a .css or .js subpage of a user page?
1222          * @return bool
1223          * @todo FIXME: Rename to isUserConfigPage()
1224          */
1225         public function isCssJsSubpage() {
1226                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1227                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1228                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1229         }
1230
1231         /**
1232          * Trim down a .css or .js subpage title to get the corresponding skin name
1233          *
1234          * @return string Containing skin name from .css or .js subpage title
1235          */
1236         public function getSkinFromCssJsSubpage() {
1237                 $subpage = explode( '/', $this->mTextform );
1238                 $subpage = $subpage[count( $subpage ) - 1];
1239                 $lastdot = strrpos( $subpage, '.' );
1240                 if ( $lastdot === false ) {
1241                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1242                 }
1243                 return substr( $subpage, 0, $lastdot );
1244         }
1245
1246         /**
1247          * Is this a .css subpage of a user page?
1248          *
1249          * @return bool
1250          */
1251         public function isCssSubpage() {
1252                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1253                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1254         }
1255
1256         /**
1257          * Is this a .js subpage of a user page?
1258          *
1259          * @return bool
1260          */
1261         public function isJsSubpage() {
1262                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1263                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1264         }
1265
1266         /**
1267          * Is this a talk page of some sort?
1268          *
1269          * @return bool
1270          */
1271         public function isTalkPage() {
1272                 return MWNamespace::isTalk( $this->getNamespace() );
1273         }
1274
1275         /**
1276          * Get a Title object associated with the talk page of this article
1277          *
1278          * @return Title The object for the talk page
1279          */
1280         public function getTalkPage() {
1281                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1282         }
1283
1284         /**
1285          * Get a title object associated with the subject page of this
1286          * talk page
1287          *
1288          * @return Title The object for the subject page
1289          */
1290         public function getSubjectPage() {
1291                 // Is this the same title?
1292                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1293                 if ( $this->getNamespace() == $subjectNS ) {
1294                         return $this;
1295                 }
1296                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1297         }
1298
1299         /**
1300          * Get the other title for this page, if this is a subject page
1301          * get the talk page, if it is a subject page get the talk page
1302          *
1303          * @since 1.25
1304          * @throws MWException
1305          * @return Title
1306          */
1307         public function getOtherPage() {
1308                 if ( $this->isSpecialPage() ) {
1309                         throw new MWException( 'Special pages cannot have other pages' );
1310                 }
1311                 if ( $this->isTalkPage() ) {
1312                         return $this->getSubjectPage();
1313                 } else {
1314                         return $this->getTalkPage();
1315                 }
1316         }
1317
1318         /**
1319          * Get the default namespace index, for when there is no namespace
1320          *
1321          * @return int Default namespace index
1322          */
1323         public function getDefaultNamespace() {
1324                 return $this->mDefaultNamespace;
1325         }
1326
1327         /**
1328          * Get the Title fragment (i.e.\ the bit after the #) in text form
1329          *
1330          * Use Title::hasFragment to check for a fragment
1331          *
1332          * @return string Title fragment
1333          */
1334         public function getFragment() {
1335                 return $this->mFragment;
1336         }
1337
1338         /**
1339          * Check if a Title fragment is set
1340          *
1341          * @return bool
1342          * @since 1.23
1343          */
1344         public function hasFragment() {
1345                 return $this->mFragment !== '';
1346         }
1347
1348         /**
1349          * Get the fragment in URL form, including the "#" character if there is one
1350          * @return string Fragment in URL form
1351          */
1352         public function getFragmentForURL() {
1353                 if ( !$this->hasFragment() ) {
1354                         return '';
1355                 } else {
1356                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1357                 }
1358         }
1359
1360         /**
1361          * Set the fragment for this title. Removes the first character from the
1362          * specified fragment before setting, so it assumes you're passing it with
1363          * an initial "#".
1364          *
1365          * Deprecated for public use, use Title::makeTitle() with fragment parameter,
1366          * or Title::createFragmentTarget().
1367          * Still in active use privately.
1368          *
1369          * @private
1370          * @param string $fragment Text
1371          */
1372         public function setFragment( $fragment ) {
1373                 $this->mFragment = strtr( substr( $fragment, 1 ), '_', ' ' );
1374         }
1375
1376         /**
1377          * Creates a new Title for a different fragment of the same page.
1378          *
1379          * @since 1.27
1380          * @param string $fragment
1381          * @return Title
1382          */
1383         public function createFragmentTarget( $fragment ) {
1384                 return self::makeTitle(
1385                         $this->getNamespace(),
1386                         $this->getText(),
1387                         $fragment,
1388                         $this->getInterwiki()
1389                 );
1390
1391         }
1392
1393         /**
1394          * Prefix some arbitrary text with the namespace or interwiki prefix
1395          * of this object
1396          *
1397          * @param string $name The text
1398          * @return string The prefixed text
1399          */
1400         private function prefix( $name ) {
1401                 $p = '';
1402                 if ( $this->isExternal() ) {
1403                         $p = $this->mInterwiki . ':';
1404                 }
1405
1406                 if ( 0 != $this->mNamespace ) {
1407                         $p .= $this->getNsText() . ':';
1408                 }
1409                 return $p . $name;
1410         }
1411
1412         /**
1413          * Get the prefixed database key form
1414          *
1415          * @return string The prefixed title, with underscores and
1416          *  any interwiki and namespace prefixes
1417          */
1418         public function getPrefixedDBkey() {
1419                 $s = $this->prefix( $this->mDbkeyform );
1420                 $s = strtr( $s, ' ', '_' );
1421                 return $s;
1422         }
1423
1424         /**
1425          * Get the prefixed title with spaces.
1426          * This is the form usually used for display
1427          *
1428          * @return string The prefixed title, with spaces
1429          */
1430         public function getPrefixedText() {
1431                 if ( $this->mPrefixedText === null ) {
1432                         $s = $this->prefix( $this->mTextform );
1433                         $s = strtr( $s, '_', ' ' );
1434                         $this->mPrefixedText = $s;
1435                 }
1436                 return $this->mPrefixedText;
1437         }
1438
1439         /**
1440          * Return a string representation of this title
1441          *
1442          * @return string Representation of this title
1443          */
1444         public function __toString() {
1445                 return $this->getPrefixedText();
1446         }
1447
1448         /**
1449          * Get the prefixed title with spaces, plus any fragment
1450          * (part beginning with '#')
1451          *
1452          * @return string The prefixed title, with spaces and the fragment, including '#'
1453          */
1454         public function getFullText() {
1455                 $text = $this->getPrefixedText();
1456                 if ( $this->hasFragment() ) {
1457                         $text .= '#' . $this->getFragment();
1458                 }
1459                 return $text;
1460         }
1461
1462         /**
1463          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1464          *
1465          * @par Example:
1466          * @code
1467          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1468          * # returns: 'Foo'
1469          * @endcode
1470          *
1471          * @return string Root name
1472          * @since 1.20
1473          */
1474         public function getRootText() {
1475                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1476                         return $this->getText();
1477                 }
1478
1479                 return strtok( $this->getText(), '/' );
1480         }
1481
1482         /**
1483          * Get the root page name title, i.e. the leftmost part before any slashes
1484          *
1485          * @par Example:
1486          * @code
1487          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1488          * # returns: Title{User:Foo}
1489          * @endcode
1490          *
1491          * @return Title Root title
1492          * @since 1.20
1493          */
1494         public function getRootTitle() {
1495                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1496         }
1497
1498         /**
1499          * Get the base page name without a namespace, i.e. the part before the subpage name
1500          *
1501          * @par Example:
1502          * @code
1503          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1504          * # returns: 'Foo/Bar'
1505          * @endcode
1506          *
1507          * @return string Base name
1508          */
1509         public function getBaseText() {
1510                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1511                         return $this->getText();
1512                 }
1513
1514                 $parts = explode( '/', $this->getText() );
1515                 # Don't discard the real title if there's no subpage involved
1516                 if ( count( $parts ) > 1 ) {
1517                         unset( $parts[count( $parts ) - 1] );
1518                 }
1519                 return implode( '/', $parts );
1520         }
1521
1522         /**
1523          * Get the base page name title, i.e. the part before the subpage name
1524          *
1525          * @par Example:
1526          * @code
1527          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1528          * # returns: Title{User:Foo/Bar}
1529          * @endcode
1530          *
1531          * @return Title Base title
1532          * @since 1.20
1533          */
1534         public function getBaseTitle() {
1535                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1536         }
1537
1538         /**
1539          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1540          *
1541          * @par Example:
1542          * @code
1543          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1544          * # returns: "Baz"
1545          * @endcode
1546          *
1547          * @return string Subpage name
1548          */
1549         public function getSubpageText() {
1550                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1551                         return $this->mTextform;
1552                 }
1553                 $parts = explode( '/', $this->mTextform );
1554                 return $parts[count( $parts ) - 1];
1555         }
1556
1557         /**
1558          * Get the title for a subpage of the current page
1559          *
1560          * @par Example:
1561          * @code
1562          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1563          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1564          * @endcode
1565          *
1566          * @param string $text The subpage name to add to the title
1567          * @return Title Subpage title
1568          * @since 1.20
1569          */
1570         public function getSubpage( $text ) {
1571                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1572         }
1573
1574         /**
1575          * Get a URL-encoded form of the subpage text
1576          *
1577          * @return string URL-encoded subpage name
1578          */
1579         public function getSubpageUrlForm() {
1580                 $text = $this->getSubpageText();
1581                 $text = wfUrlencode( strtr( $text, ' ', '_' ) );
1582                 return $text;
1583         }
1584
1585         /**
1586          * Get a URL-encoded title (not an actual URL) including interwiki
1587          *
1588          * @return string The URL-encoded form
1589          */
1590         public function getPrefixedURL() {
1591                 $s = $this->prefix( $this->mDbkeyform );
1592                 $s = wfUrlencode( strtr( $s, ' ', '_' ) );
1593                 return $s;
1594         }
1595
1596         /**
1597          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1598          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1599          * second argument named variant. This was deprecated in favor
1600          * of passing an array of option with a "variant" key
1601          * Once $query2 is removed for good, this helper can be dropped
1602          * and the wfArrayToCgi moved to getLocalURL();
1603          *
1604          * @since 1.19 (r105919)
1605          * @param array|string $query
1606          * @param bool $query2
1607          * @return string
1608          */
1609         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1610                 if ( $query2 !== false ) {
1611                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1612                                 "method called with a second parameter is deprecated. Add your " .
1613                                 "parameter to an array passed as the first parameter.", "1.19" );
1614                 }
1615                 if ( is_array( $query ) ) {
1616                         $query = wfArrayToCgi( $query );
1617                 }
1618                 if ( $query2 ) {
1619                         if ( is_string( $query2 ) ) {
1620                                 // $query2 is a string, we will consider this to be
1621                                 // a deprecated $variant argument and add it to the query
1622                                 $query2 = wfArrayToCgi( [ 'variant' => $query2 ] );
1623                         } else {
1624                                 $query2 = wfArrayToCgi( $query2 );
1625                         }
1626                         // If we have $query content add a & to it first
1627                         if ( $query ) {
1628                                 $query .= '&';
1629                         }
1630                         // Now append the queries together
1631                         $query .= $query2;
1632                 }
1633                 return $query;
1634         }
1635
1636         /**
1637          * Get a real URL referring to this title, with interwiki link and
1638          * fragment
1639          *
1640          * @see self::getLocalURL for the arguments.
1641          * @see wfExpandUrl
1642          * @param array|string $query
1643          * @param bool $query2
1644          * @param string $proto Protocol type to use in URL
1645          * @return string The URL
1646          */
1647         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1648                 $query = self::fixUrlQueryArgs( $query, $query2 );
1649
1650                 # Hand off all the decisions on urls to getLocalURL
1651                 $url = $this->getLocalURL( $query );
1652
1653                 # Expand the url to make it a full url. Note that getLocalURL has the
1654                 # potential to output full urls for a variety of reasons, so we use
1655                 # wfExpandUrl instead of simply prepending $wgServer
1656                 $url = wfExpandUrl( $url, $proto );
1657
1658                 # Finally, add the fragment.
1659                 $url .= $this->getFragmentForURL();
1660
1661                 Hooks::run( 'GetFullURL', [ &$this, &$url, $query ] );
1662                 return $url;
1663         }
1664
1665         /**
1666          * Get a URL with no fragment or server name (relative URL) from a Title object.
1667          * If this page is generated with action=render, however,
1668          * $wgServer is prepended to make an absolute URL.
1669          *
1670          * @see self::getFullURL to always get an absolute URL.
1671          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1672          *  valid to link, locally, to the current Title.
1673          * @see self::newFromText to produce a Title object.
1674          *
1675          * @param string|array $query An optional query string,
1676          *   not used for interwiki links. Can be specified as an associative array as well,
1677          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1678          *   Some query patterns will trigger various shorturl path replacements.
1679          * @param array $query2 An optional secondary query array. This one MUST
1680          *   be an array. If a string is passed it will be interpreted as a deprecated
1681          *   variant argument and urlencoded into a variant= argument.
1682          *   This second query argument will be added to the $query
1683          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1684          *   pair in the first parameter array instead.
1685          *
1686          * @return string String of the URL.
1687          */
1688         public function getLocalURL( $query = '', $query2 = false ) {
1689                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1690
1691                 $query = self::fixUrlQueryArgs( $query, $query2 );
1692
1693                 $interwiki = self::getInterwikiLookup()->fetch( $this->mInterwiki );
1694                 if ( $interwiki ) {
1695                         $namespace = $this->getNsText();
1696                         if ( $namespace != '' ) {
1697                                 # Can this actually happen? Interwikis shouldn't be parsed.
1698                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1699                                 $namespace .= ':';
1700                         }
1701                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1702                         $url = wfAppendQuery( $url, $query );
1703                 } else {
1704                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1705                         if ( $query == '' ) {
1706                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1707                                 Hooks::run( 'GetLocalURL::Article', [ &$this, &$url ] );
1708                         } else {
1709                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1710                                 $url = false;
1711                                 $matches = [];
1712
1713                                 if ( !empty( $wgActionPaths )
1714                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1715                                 ) {
1716                                         $action = urldecode( $matches[2] );
1717                                         if ( isset( $wgActionPaths[$action] ) ) {
1718                                                 $query = $matches[1];
1719                                                 if ( isset( $matches[4] ) ) {
1720                                                         $query .= $matches[4];
1721                                                 }
1722                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1723                                                 if ( $query != '' ) {
1724                                                         $url = wfAppendQuery( $url, $query );
1725                                                 }
1726                                         }
1727                                 }
1728
1729                                 if ( $url === false
1730                                         && $wgVariantArticlePath
1731                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1732                                         && $this->getPageLanguage()->equals( $wgContLang )
1733                                         && $this->getPageLanguage()->hasVariants()
1734                                 ) {
1735                                         $variant = urldecode( $matches[1] );
1736                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1737                                                 // Only do the variant replacement if the given variant is a valid
1738                                                 // variant for the page's language.
1739                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1740                                                 $url = str_replace( '$1', $dbkey, $url );
1741                                         }
1742                                 }
1743
1744                                 if ( $url === false ) {
1745                                         if ( $query == '-' ) {
1746                                                 $query = '';
1747                                         }
1748                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1749                                 }
1750                         }
1751
1752                         Hooks::run( 'GetLocalURL::Internal', [ &$this, &$url, $query ] );
1753
1754                         // @todo FIXME: This causes breakage in various places when we
1755                         // actually expected a local URL and end up with dupe prefixes.
1756                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1757                                 $url = $wgServer . $url;
1758                         }
1759                 }
1760                 Hooks::run( 'GetLocalURL', [ &$this, &$url, $query ] );
1761                 return $url;
1762         }
1763
1764         /**
1765          * Get a URL that's the simplest URL that will be valid to link, locally,
1766          * to the current Title.  It includes the fragment, but does not include
1767          * the server unless action=render is used (or the link is external).  If
1768          * there's a fragment but the prefixed text is empty, we just return a link
1769          * to the fragment.
1770          *
1771          * The result obviously should not be URL-escaped, but does need to be
1772          * HTML-escaped if it's being output in HTML.
1773          *
1774          * @param array $query
1775          * @param bool $query2
1776          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1777          * @see self::getLocalURL for the arguments.
1778          * @return string The URL
1779          */
1780         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1781                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1782                         $ret = $this->getFullURL( $query, $query2, $proto );
1783                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1784                         $ret = $this->getFragmentForURL();
1785                 } else {
1786                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1787                 }
1788                 return $ret;
1789         }
1790
1791         /**
1792          * Get the URL form for an internal link.
1793          * - Used in various CDN-related code, in case we have a different
1794          * internal hostname for the server from the exposed one.
1795          *
1796          * This uses $wgInternalServer to qualify the path, or $wgServer
1797          * if $wgInternalServer is not set. If the server variable used is
1798          * protocol-relative, the URL will be expanded to http://
1799          *
1800          * @see self::getLocalURL for the arguments.
1801          * @return string The URL
1802          */
1803         public function getInternalURL( $query = '', $query2 = false ) {
1804                 global $wgInternalServer, $wgServer;
1805                 $query = self::fixUrlQueryArgs( $query, $query2 );
1806                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1807                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1808                 Hooks::run( 'GetInternalURL', [ &$this, &$url, $query ] );
1809                 return $url;
1810         }
1811
1812         /**
1813          * Get the URL for a canonical link, for use in things like IRC and
1814          * e-mail notifications. Uses $wgCanonicalServer and the
1815          * GetCanonicalURL hook.
1816          *
1817          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1818          *
1819          * @see self::getLocalURL for the arguments.
1820          * @return string The URL
1821          * @since 1.18
1822          */
1823         public function getCanonicalURL( $query = '', $query2 = false ) {
1824                 $query = self::fixUrlQueryArgs( $query, $query2 );
1825                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1826                 Hooks::run( 'GetCanonicalURL', [ &$this, &$url, $query ] );
1827                 return $url;
1828         }
1829
1830         /**
1831          * Get the edit URL for this Title
1832          *
1833          * @return string The URL, or a null string if this is an interwiki link
1834          */
1835         public function getEditURL() {
1836                 if ( $this->isExternal() ) {
1837                         return '';
1838                 }
1839                 $s = $this->getLocalURL( 'action=edit' );
1840
1841                 return $s;
1842         }
1843
1844         /**
1845          * Can $user perform $action on this page?
1846          * This skips potentially expensive cascading permission checks
1847          * as well as avoids expensive error formatting
1848          *
1849          * Suitable for use for nonessential UI controls in common cases, but
1850          * _not_ for functional access control.
1851          *
1852          * May provide false positives, but should never provide a false negative.
1853          *
1854          * @param string $action Action that permission needs to be checked for
1855          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1856          * @return bool
1857          */
1858         public function quickUserCan( $action, $user = null ) {
1859                 return $this->userCan( $action, $user, false );
1860         }
1861
1862         /**
1863          * Can $user perform $action on this page?
1864          *
1865          * @param string $action Action that permission needs to be checked for
1866          * @param User $user User to check (since 1.19); $wgUser will be used if not
1867          *   provided.
1868          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1869          * @return bool
1870          */
1871         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1872                 if ( !$user instanceof User ) {
1873                         global $wgUser;
1874                         $user = $wgUser;
1875                 }
1876
1877                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1878         }
1879
1880         /**
1881          * Can $user perform $action on this page?
1882          *
1883          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1884          *
1885          * @param string $action Action that permission needs to be checked for
1886          * @param User $user User to check
1887          * @param string $rigor One of (quick,full,secure)
1888          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
1889          *   - full   : does cheap and expensive checks possibly from a slave
1890          *   - secure : does cheap and expensive checks, using the master as needed
1891          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1892          *   whose corresponding errors may be ignored.
1893          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
1894          */
1895         public function getUserPermissionsErrors(
1896                 $action, $user, $rigor = 'secure', $ignoreErrors = []
1897         ) {
1898                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1899
1900                 // Remove the errors being ignored.
1901                 foreach ( $errors as $index => $error ) {
1902                         $errKey = is_array( $error ) ? $error[0] : $error;
1903
1904                         if ( in_array( $errKey, $ignoreErrors ) ) {
1905                                 unset( $errors[$index] );
1906                         }
1907                         if ( $errKey instanceof MessageSpecifier && in_array( $errKey->getKey(), $ignoreErrors ) ) {
1908                                 unset( $errors[$index] );
1909                         }
1910                 }
1911
1912                 return $errors;
1913         }
1914
1915         /**
1916          * Permissions checks that fail most often, and which are easiest to test.
1917          *
1918          * @param string $action The action to check
1919          * @param User $user User to check
1920          * @param array $errors List of current errors
1921          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1922          * @param bool $short Short circuit on first error
1923          *
1924          * @return array List of errors
1925          */
1926         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1927                 if ( !Hooks::run( 'TitleQuickPermissions',
1928                         [ $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ] )
1929                 ) {
1930                         return $errors;
1931                 }
1932
1933                 if ( $action == 'create' ) {
1934                         if (
1935                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1936                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1937                         ) {
1938                                 $errors[] = $user->isAnon() ? [ 'nocreatetext' ] : [ 'nocreate-loggedin' ];
1939                         }
1940                 } elseif ( $action == 'move' ) {
1941                         if ( !$user->isAllowed( 'move-rootuserpages' )
1942                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1943                                 // Show user page-specific message only if the user can move other pages
1944                                 $errors[] = [ 'cant-move-user-page' ];
1945                         }
1946
1947                         // Check if user is allowed to move files if it's a file
1948                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1949                                 $errors[] = [ 'movenotallowedfile' ];
1950                         }
1951
1952                         // Check if user is allowed to move category pages if it's a category page
1953                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1954                                 $errors[] = [ 'cant-move-category-page' ];
1955                         }
1956
1957                         if ( !$user->isAllowed( 'move' ) ) {
1958                                 // User can't move anything
1959                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1960                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1961                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1962                                         // custom message if logged-in users without any special rights can move
1963                                         $errors[] = [ 'movenologintext' ];
1964                                 } else {
1965                                         $errors[] = [ 'movenotallowed' ];
1966                                 }
1967                         }
1968                 } elseif ( $action == 'move-target' ) {
1969                         if ( !$user->isAllowed( 'move' ) ) {
1970                                 // User can't move anything
1971                                 $errors[] = [ 'movenotallowed' ];
1972                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1973                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1974                                 // Show user page-specific message only if the user can move other pages
1975                                 $errors[] = [ 'cant-move-to-user-page' ];
1976                         } elseif ( !$user->isAllowed( 'move-categorypages' )
1977                                         && $this->mNamespace == NS_CATEGORY ) {
1978                                 // Show category page-specific message only if the user can move other pages
1979                                 $errors[] = [ 'cant-move-to-category-page' ];
1980                         }
1981                 } elseif ( !$user->isAllowed( $action ) ) {
1982                         $errors[] = $this->missingPermissionError( $action, $short );
1983                 }
1984
1985                 return $errors;
1986         }
1987
1988         /**
1989          * Add the resulting error code to the errors array
1990          *
1991          * @param array $errors List of current errors
1992          * @param array $result Result of errors
1993          *
1994          * @return array List of errors
1995          */
1996         private function resultToError( $errors, $result ) {
1997                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1998                         // A single array representing an error
1999                         $errors[] = $result;
2000                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2001                         // A nested array representing multiple errors
2002                         $errors = array_merge( $errors, $result );
2003                 } elseif ( $result !== '' && is_string( $result ) ) {
2004                         // A string representing a message-id
2005                         $errors[] = [ $result ];
2006                 } elseif ( $result instanceof MessageSpecifier ) {
2007                         // A message specifier representing an error
2008                         $errors[] = [ $result ];
2009                 } elseif ( $result === false ) {
2010                         // a generic "We don't want them to do that"
2011                         $errors[] = [ 'badaccess-group0' ];
2012                 }
2013                 return $errors;
2014         }
2015
2016         /**
2017          * Check various permission hooks
2018          *
2019          * @param string $action The action to check
2020          * @param User $user User to check
2021          * @param array $errors List of current errors
2022          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2023          * @param bool $short Short circuit on first error
2024          *
2025          * @return array List of errors
2026          */
2027         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2028                 // Use getUserPermissionsErrors instead
2029                 $result = '';
2030                 if ( !Hooks::run( 'userCan', [ &$this, &$user, $action, &$result ] ) ) {
2031                         return $result ? [] : [ [ 'badaccess-group0' ] ];
2032                 }
2033                 // Check getUserPermissionsErrors hook
2034                 if ( !Hooks::run( 'getUserPermissionsErrors', [ &$this, &$user, $action, &$result ] ) ) {
2035                         $errors = $this->resultToError( $errors, $result );
2036                 }
2037                 // Check getUserPermissionsErrorsExpensive hook
2038                 if (
2039                         $rigor !== 'quick'
2040                         && !( $short && count( $errors ) > 0 )
2041                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', [ &$this, &$user, $action, &$result ] )
2042                 ) {
2043                         $errors = $this->resultToError( $errors, $result );
2044                 }
2045
2046                 return $errors;
2047         }
2048
2049         /**
2050          * Check permissions on special pages & namespaces
2051          *
2052          * @param string $action The action to check
2053          * @param User $user User to check
2054          * @param array $errors List of current errors
2055          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2056          * @param bool $short Short circuit on first error
2057          *
2058          * @return array List of errors
2059          */
2060         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2061                 # Only 'createaccount' can be performed on special pages,
2062                 # which don't actually exist in the DB.
2063                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2064                         $errors[] = [ 'ns-specialprotected' ];
2065                 }
2066
2067                 # Check $wgNamespaceProtection for restricted namespaces
2068                 if ( $this->isNamespaceProtected( $user ) ) {
2069                         $ns = $this->mNamespace == NS_MAIN ?
2070                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2071                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2072                                 [ 'protectedinterface', $action ] : [ 'namespaceprotected', $ns, $action ];
2073                 }
2074
2075                 return $errors;
2076         }
2077
2078         /**
2079          * Check CSS/JS sub-page permissions
2080          *
2081          * @param string $action The action to check
2082          * @param User $user User to check
2083          * @param array $errors List of current errors
2084          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2085          * @param bool $short Short circuit on first error
2086          *
2087          * @return array List of errors
2088          */
2089         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2090                 # Protect css/js subpages of user pages
2091                 # XXX: this might be better using restrictions
2092                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2093                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2094                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2095                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2096                                         $errors[] = [ 'mycustomcssprotected', $action ];
2097                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2098                                         $errors[] = [ 'mycustomjsprotected', $action ];
2099                                 }
2100                         } else {
2101                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2102                                         $errors[] = [ 'customcssprotected', $action ];
2103                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2104                                         $errors[] = [ 'customjsprotected', $action ];
2105                                 }
2106                         }
2107                 }
2108
2109                 return $errors;
2110         }
2111
2112         /**
2113          * Check against page_restrictions table requirements on this
2114          * page. The user must possess all required rights for this
2115          * action.
2116          *
2117          * @param string $action The action to check
2118          * @param User $user User to check
2119          * @param array $errors List of current errors
2120          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2121          * @param bool $short Short circuit on first error
2122          *
2123          * @return array List of errors
2124          */
2125         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2126                 foreach ( $this->getRestrictions( $action ) as $right ) {
2127                         // Backwards compatibility, rewrite sysop -> editprotected
2128                         if ( $right == 'sysop' ) {
2129                                 $right = 'editprotected';
2130                         }
2131                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2132                         if ( $right == 'autoconfirmed' ) {
2133                                 $right = 'editsemiprotected';
2134                         }
2135                         if ( $right == '' ) {
2136                                 continue;
2137                         }
2138                         if ( !$user->isAllowed( $right ) ) {
2139                                 $errors[] = [ 'protectedpagetext', $right, $action ];
2140                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2141                                 $errors[] = [ 'protectedpagetext', 'protect', $action ];
2142                         }
2143                 }
2144
2145                 return $errors;
2146         }
2147
2148         /**
2149          * Check restrictions on cascading pages.
2150          *
2151          * @param string $action The action to check
2152          * @param User $user User to check
2153          * @param array $errors List of current errors
2154          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2155          * @param bool $short Short circuit on first error
2156          *
2157          * @return array List of errors
2158          */
2159         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2160                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2161                         # We /could/ use the protection level on the source page, but it's
2162                         # fairly ugly as we have to establish a precedence hierarchy for pages
2163                         # included by multiple cascade-protected pages. So just restrict
2164                         # it to people with 'protect' permission, as they could remove the
2165                         # protection anyway.
2166                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2167                         # Cascading protection depends on more than this page...
2168                         # Several cascading protected pages may include this page...
2169                         # Check each cascading level
2170                         # This is only for protection restrictions, not for all actions
2171                         if ( isset( $restrictions[$action] ) ) {
2172                                 foreach ( $restrictions[$action] as $right ) {
2173                                         // Backwards compatibility, rewrite sysop -> editprotected
2174                                         if ( $right == 'sysop' ) {
2175                                                 $right = 'editprotected';
2176                                         }
2177                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2178                                         if ( $right == 'autoconfirmed' ) {
2179                                                 $right = 'editsemiprotected';
2180                                         }
2181                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2182                                                 $pages = '';
2183                                                 foreach ( $cascadingSources as $page ) {
2184                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2185                                                 }
2186                                                 $errors[] = [ 'cascadeprotected', count( $cascadingSources ), $pages, $action ];
2187                                         }
2188                                 }
2189                         }
2190                 }
2191
2192                 return $errors;
2193         }
2194
2195         /**
2196          * Check action permissions not already checked in checkQuickPermissions
2197          *
2198          * @param string $action The action to check
2199          * @param User $user User to check
2200          * @param array $errors List of current errors
2201          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2202          * @param bool $short Short circuit on first error
2203          *
2204          * @return array List of errors
2205          */
2206         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2207                 global $wgDeleteRevisionsLimit, $wgLang;
2208
2209                 if ( $action == 'protect' ) {
2210                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2211                                 // If they can't edit, they shouldn't protect.
2212                                 $errors[] = [ 'protect-cantedit' ];
2213                         }
2214                 } elseif ( $action == 'create' ) {
2215                         $title_protection = $this->getTitleProtection();
2216                         if ( $title_protection ) {
2217                                 if ( $title_protection['permission'] == ''
2218                                         || !$user->isAllowed( $title_protection['permission'] )
2219                                 ) {
2220                                         $errors[] = [
2221                                                 'titleprotected',
2222                                                 User::whoIs( $title_protection['user'] ),
2223                                                 $title_protection['reason']
2224                                         ];
2225                                 }
2226                         }
2227                 } elseif ( $action == 'move' ) {
2228                         // Check for immobile pages
2229                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2230                                 // Specific message for this case
2231                                 $errors[] = [ 'immobile-source-namespace', $this->getNsText() ];
2232                         } elseif ( !$this->isMovable() ) {
2233                                 // Less specific message for rarer cases
2234                                 $errors[] = [ 'immobile-source-page' ];
2235                         }
2236                 } elseif ( $action == 'move-target' ) {
2237                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2238                                 $errors[] = [ 'immobile-target-namespace', $this->getNsText() ];
2239                         } elseif ( !$this->isMovable() ) {
2240                                 $errors[] = [ 'immobile-target-page' ];
2241                         }
2242                 } elseif ( $action == 'delete' ) {
2243                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, [], $rigor, true );
2244                         if ( !$tempErrors ) {
2245                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2246                                         $user, $tempErrors, $rigor, true );
2247                         }
2248                         if ( $tempErrors ) {
2249                                 // If protection keeps them from editing, they shouldn't be able to delete.
2250                                 $errors[] = [ 'deleteprotected' ];
2251                         }
2252                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2253                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2254                         ) {
2255                                 $errors[] = [ 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) ];
2256                         }
2257                 }
2258                 return $errors;
2259         }
2260
2261         /**
2262          * Check that the user isn't blocked from editing.
2263          *
2264          * @param string $action The action to check
2265          * @param User $user User to check
2266          * @param array $errors List of current errors
2267          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2268          * @param bool $short Short circuit on first error
2269          *
2270          * @return array List of errors
2271          */
2272         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2273                 // Account creation blocks handled at userlogin.
2274                 // Unblocking handled in SpecialUnblock
2275                 if ( $rigor === 'quick' || in_array( $action, [ 'createaccount', 'unblock' ] ) ) {
2276                         return $errors;
2277                 }
2278
2279                 global $wgEmailConfirmToEdit;
2280
2281                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2282                         $errors[] = [ 'confirmedittext' ];
2283                 }
2284
2285                 $useSlave = ( $rigor !== 'secure' );
2286                 if ( ( $action == 'edit' || $action == 'create' )
2287                         && !$user->isBlockedFrom( $this, $useSlave )
2288                 ) {
2289                         // Don't block the user from editing their own talk page unless they've been
2290                         // explicitly blocked from that too.
2291                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2292                         // @todo FIXME: Pass the relevant context into this function.
2293                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2294                 }
2295
2296                 return $errors;
2297         }
2298
2299         /**
2300          * Check that the user is allowed to read this page.
2301          *
2302          * @param string $action The action to check
2303          * @param User $user User to check
2304          * @param array $errors List of current errors
2305          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2306          * @param bool $short Short circuit on first error
2307          *
2308          * @return array List of errors
2309          */
2310         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2311                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2312
2313                 $whitelisted = false;
2314                 if ( User::isEveryoneAllowed( 'read' ) ) {
2315                         # Shortcut for public wikis, allows skipping quite a bit of code
2316                         $whitelisted = true;
2317                 } elseif ( $user->isAllowed( 'read' ) ) {
2318                         # If the user is allowed to read pages, he is allowed to read all pages
2319                         $whitelisted = true;
2320                 } elseif ( $this->isSpecial( 'Userlogin' )
2321                         || $this->isSpecial( 'ChangePassword' )
2322                         || $this->isSpecial( 'PasswordReset' )
2323                 ) {
2324                         # Always grant access to the login page.
2325                         # Even anons need to be able to log in.
2326                         $whitelisted = true;
2327                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2328                         # Time to check the whitelist
2329                         # Only do these checks is there's something to check against
2330                         $name = $this->getPrefixedText();
2331                         $dbName = $this->getPrefixedDBkey();
2332
2333                         // Check for explicit whitelisting with and without underscores
2334                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2335                                 $whitelisted = true;
2336                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2337                                 # Old settings might have the title prefixed with
2338                                 # a colon for main-namespace pages
2339                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2340                                         $whitelisted = true;
2341                                 }
2342                         } elseif ( $this->isSpecialPage() ) {
2343                                 # If it's a special page, ditch the subpage bit and check again
2344                                 $name = $this->getDBkey();
2345                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2346                                 if ( $name ) {
2347                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2348                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2349                                                 $whitelisted = true;
2350                                         }
2351                                 }
2352                         }
2353                 }
2354
2355                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2356                         $name = $this->getPrefixedText();
2357                         // Check for regex whitelisting
2358                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2359                                 if ( preg_match( $listItem, $name ) ) {
2360                                         $whitelisted = true;
2361                                         break;
2362                                 }
2363                         }
2364                 }
2365
2366                 if ( !$whitelisted ) {
2367                         # If the title is not whitelisted, give extensions a chance to do so...
2368                         Hooks::run( 'TitleReadWhitelist', [ $this, $user, &$whitelisted ] );
2369                         if ( !$whitelisted ) {
2370                                 $errors[] = $this->missingPermissionError( $action, $short );
2371                         }
2372                 }
2373
2374                 return $errors;
2375         }
2376
2377         /**
2378          * Get a description array when the user doesn't have the right to perform
2379          * $action (i.e. when User::isAllowed() returns false)
2380          *
2381          * @param string $action The action to check
2382          * @param bool $short Short circuit on first error
2383          * @return array List of errors
2384          */
2385         private function missingPermissionError( $action, $short ) {
2386                 // We avoid expensive display logic for quickUserCan's and such
2387                 if ( $short ) {
2388                         return [ 'badaccess-group0' ];
2389                 }
2390
2391                 $groups = array_map( [ 'User', 'makeGroupLinkWiki' ],
2392                         User::getGroupsWithPermission( $action ) );
2393
2394                 if ( count( $groups ) ) {
2395                         global $wgLang;
2396                         return [
2397                                 'badaccess-groups',
2398                                 $wgLang->commaList( $groups ),
2399                                 count( $groups )
2400                         ];
2401                 } else {
2402                         return [ 'badaccess-group0' ];
2403                 }
2404         }
2405
2406         /**
2407          * Can $user perform $action on this page? This is an internal function,
2408          * with multiple levels of checks depending on performance needs; see $rigor below.
2409          * It does not check wfReadOnly().
2410          *
2411          * @param string $action Action that permission needs to be checked for
2412          * @param User $user User to check
2413          * @param string $rigor One of (quick,full,secure)
2414          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
2415          *   - full   : does cheap and expensive checks possibly from a slave
2416          *   - secure : does cheap and expensive checks, using the master as needed
2417          * @param bool $short Set this to true to stop after the first permission error.
2418          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2419          */
2420         protected function getUserPermissionsErrorsInternal(
2421                 $action, $user, $rigor = 'secure', $short = false
2422         ) {
2423                 if ( $rigor === true ) {
2424                         $rigor = 'secure'; // b/c
2425                 } elseif ( $rigor === false ) {
2426                         $rigor = 'quick'; // b/c
2427                 } elseif ( !in_array( $rigor, [ 'quick', 'full', 'secure' ] ) ) {
2428                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2429                 }
2430
2431                 # Read has special handling
2432                 if ( $action == 'read' ) {
2433                         $checks = [
2434                                 'checkPermissionHooks',
2435                                 'checkReadPermissions',
2436                         ];
2437                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2438                 # here as it will lead to duplicate error messages. This is okay to do
2439                 # since anywhere that checks for create will also check for edit, and
2440                 # those checks are called for edit.
2441                 } elseif ( $action == 'create' ) {
2442                         $checks = [
2443                                 'checkQuickPermissions',
2444                                 'checkPermissionHooks',
2445                                 'checkPageRestrictions',
2446                                 'checkCascadingSourcesRestrictions',
2447                                 'checkActionPermissions',
2448                                 'checkUserBlock'
2449                         ];
2450                 } else {
2451                         $checks = [
2452                                 'checkQuickPermissions',
2453                                 'checkPermissionHooks',
2454                                 'checkSpecialsAndNSPermissions',
2455                                 'checkCSSandJSPermissions',
2456                                 'checkPageRestrictions',
2457                                 'checkCascadingSourcesRestrictions',
2458                                 'checkActionPermissions',
2459                                 'checkUserBlock'
2460                         ];
2461                 }
2462
2463                 $errors = [];
2464                 while ( count( $checks ) > 0 &&
2465                                 !( $short && count( $errors ) > 0 ) ) {
2466                         $method = array_shift( $checks );
2467                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2468                 }
2469
2470                 return $errors;
2471         }
2472
2473         /**
2474          * Get a filtered list of all restriction types supported by this wiki.
2475          * @param bool $exists True to get all restriction types that apply to
2476          * titles that do exist, False for all restriction types that apply to
2477          * titles that do not exist
2478          * @return array
2479          */
2480         public static function getFilteredRestrictionTypes( $exists = true ) {
2481                 global $wgRestrictionTypes;
2482                 $types = $wgRestrictionTypes;
2483                 if ( $exists ) {
2484                         # Remove the create restriction for existing titles
2485                         $types = array_diff( $types, [ 'create' ] );
2486                 } else {
2487                         # Only the create and upload restrictions apply to non-existing titles
2488                         $types = array_intersect( $types, [ 'create', 'upload' ] );
2489                 }
2490                 return $types;
2491         }
2492
2493         /**
2494          * Returns restriction types for the current Title
2495          *
2496          * @return array Applicable restriction types
2497          */
2498         public function getRestrictionTypes() {
2499                 if ( $this->isSpecialPage() ) {
2500                         return [];
2501                 }
2502
2503                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2504
2505                 if ( $this->getNamespace() != NS_FILE ) {
2506                         # Remove the upload restriction for non-file titles
2507                         $types = array_diff( $types, [ 'upload' ] );
2508                 }
2509
2510                 Hooks::run( 'TitleGetRestrictionTypes', [ $this, &$types ] );
2511
2512                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2513                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2514
2515                 return $types;
2516         }
2517
2518         /**
2519          * Is this title subject to title protection?
2520          * Title protection is the one applied against creation of such title.
2521          *
2522          * @return array|bool An associative array representing any existent title
2523          *   protection, or false if there's none.
2524          */
2525         public function getTitleProtection() {
2526                 // Can't protect pages in special namespaces
2527                 if ( $this->getNamespace() < 0 ) {
2528                         return false;
2529                 }
2530
2531                 // Can't protect pages that exist.
2532                 if ( $this->exists() ) {
2533                         return false;
2534                 }
2535
2536                 if ( $this->mTitleProtection === null ) {
2537                         $dbr = wfGetDB( DB_SLAVE );
2538                         $res = $dbr->select(
2539                                 'protected_titles',
2540                                 [
2541                                         'user' => 'pt_user',
2542                                         'reason' => 'pt_reason',
2543                                         'expiry' => 'pt_expiry',
2544                                         'permission' => 'pt_create_perm'
2545                                 ],
2546                                 [ 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ],
2547                                 __METHOD__
2548                         );
2549
2550                         // fetchRow returns false if there are no rows.
2551                         $row = $dbr->fetchRow( $res );
2552                         if ( $row ) {
2553                                 if ( $row['permission'] == 'sysop' ) {
2554                                         $row['permission'] = 'editprotected'; // B/C
2555                                 }
2556                                 if ( $row['permission'] == 'autoconfirmed' ) {
2557                                         $row['permission'] = 'editsemiprotected'; // B/C
2558                                 }
2559                                 $row['expiry'] = $dbr->decodeExpiry( $row['expiry'] );
2560                         }
2561                         $this->mTitleProtection = $row;
2562                 }
2563                 return $this->mTitleProtection;
2564         }
2565
2566         /**
2567          * Remove any title protection due to page existing
2568          */
2569         public function deleteTitleProtection() {
2570                 $dbw = wfGetDB( DB_MASTER );
2571
2572                 $dbw->delete(
2573                         'protected_titles',
2574                         [ 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ],
2575                         __METHOD__
2576                 );
2577                 $this->mTitleProtection = false;
2578         }
2579
2580         /**
2581          * Is this page "semi-protected" - the *only* protection levels are listed
2582          * in $wgSemiprotectedRestrictionLevels?
2583          *
2584          * @param string $action Action to check (default: edit)
2585          * @return bool
2586          */
2587         public function isSemiProtected( $action = 'edit' ) {
2588                 global $wgSemiprotectedRestrictionLevels;
2589
2590                 $restrictions = $this->getRestrictions( $action );
2591                 $semi = $wgSemiprotectedRestrictionLevels;
2592                 if ( !$restrictions || !$semi ) {
2593                         // Not protected, or all protection is full protection
2594                         return false;
2595                 }
2596
2597                 // Remap autoconfirmed to editsemiprotected for BC
2598                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2599                         $semi[$key] = 'editsemiprotected';
2600                 }
2601                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2602                         $restrictions[$key] = 'editsemiprotected';
2603                 }
2604
2605                 return !array_diff( $restrictions, $semi );
2606         }
2607
2608         /**
2609          * Does the title correspond to a protected article?
2610          *
2611          * @param string $action The action the page is protected from,
2612          * by default checks all actions.
2613          * @return bool
2614          */
2615         public function isProtected( $action = '' ) {
2616                 global $wgRestrictionLevels;
2617
2618                 $restrictionTypes = $this->getRestrictionTypes();
2619
2620                 # Special pages have inherent protection
2621                 if ( $this->isSpecialPage() ) {
2622                         return true;
2623                 }
2624
2625                 # Check regular protection levels
2626                 foreach ( $restrictionTypes as $type ) {
2627                         if ( $action == $type || $action == '' ) {
2628                                 $r = $this->getRestrictions( $type );
2629                                 foreach ( $wgRestrictionLevels as $level ) {
2630                                         if ( in_array( $level, $r ) && $level != '' ) {
2631                                                 return true;
2632                                         }
2633                                 }
2634                         }
2635                 }
2636
2637                 return false;
2638         }
2639
2640         /**
2641          * Determines if $user is unable to edit this page because it has been protected
2642          * by $wgNamespaceProtection.
2643          *
2644          * @param User $user User object to check permissions
2645          * @return bool
2646          */
2647         public function isNamespaceProtected( User $user ) {
2648                 global $wgNamespaceProtection;
2649
2650                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2651                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2652                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2653                                         return true;
2654                                 }
2655                         }
2656                 }
2657                 return false;
2658         }
2659
2660         /**
2661          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2662          *
2663          * @return bool If the page is subject to cascading restrictions.
2664          */
2665         public function isCascadeProtected() {
2666                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2667                 return ( $sources > 0 );
2668         }
2669
2670         /**
2671          * Determines whether cascading protection sources have already been loaded from
2672          * the database.
2673          *
2674          * @param bool $getPages True to check if the pages are loaded, or false to check
2675          * if the status is loaded.
2676          * @return bool Whether or not the specified information has been loaded
2677          * @since 1.23
2678          */
2679         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2680                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2681         }
2682
2683         /**
2684          * Cascading protection: Get the source of any cascading restrictions on this page.
2685          *
2686          * @param bool $getPages Whether or not to retrieve the actual pages
2687          *        that the restrictions have come from and the actual restrictions
2688          *        themselves.
2689          * @return array Two elements: First is an array of Title objects of the
2690          *        pages from which cascading restrictions have come, false for
2691          *        none, or true if such restrictions exist but $getPages was not
2692          *        set. Second is an array like that returned by
2693          *        Title::getAllRestrictions(), or an empty array if $getPages is
2694          *        false.
2695          */
2696         public function getCascadeProtectionSources( $getPages = true ) {
2697                 $pagerestrictions = [];
2698
2699                 if ( $this->mCascadeSources !== null && $getPages ) {
2700                         return [ $this->mCascadeSources, $this->mCascadingRestrictions ];
2701                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2702                         return [ $this->mHasCascadingRestrictions, $pagerestrictions ];
2703                 }
2704
2705                 $dbr = wfGetDB( DB_SLAVE );
2706
2707                 if ( $this->getNamespace() == NS_FILE ) {
2708                         $tables = [ 'imagelinks', 'page_restrictions' ];
2709                         $where_clauses = [
2710                                 'il_to' => $this->getDBkey(),
2711                                 'il_from=pr_page',
2712                                 'pr_cascade' => 1
2713                         ];
2714                 } else {
2715                         $tables = [ 'templatelinks', 'page_restrictions' ];
2716                         $where_clauses = [
2717                                 'tl_namespace' => $this->getNamespace(),
2718                                 'tl_title' => $this->getDBkey(),
2719                                 'tl_from=pr_page',
2720                                 'pr_cascade' => 1
2721                         ];
2722                 }
2723
2724                 if ( $getPages ) {
2725                         $cols = [ 'pr_page', 'page_namespace', 'page_title',
2726                                 'pr_expiry', 'pr_type', 'pr_level' ];
2727                         $where_clauses[] = 'page_id=pr_page';
2728                         $tables[] = 'page';
2729                 } else {
2730                         $cols = [ 'pr_expiry' ];
2731                 }
2732
2733                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2734
2735                 $sources = $getPages ? [] : false;
2736                 $now = wfTimestampNow();
2737
2738                 foreach ( $res as $row ) {
2739                         $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2740                         if ( $expiry > $now ) {
2741                                 if ( $getPages ) {
2742                                         $page_id = $row->pr_page;
2743                                         $page_ns = $row->page_namespace;
2744                                         $page_title = $row->page_title;
2745                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2746                                         # Add groups needed for each restriction type if its not already there
2747                                         # Make sure this restriction type still exists
2748
2749                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2750                                                 $pagerestrictions[$row->pr_type] = [];
2751                                         }
2752
2753                                         if (
2754                                                 isset( $pagerestrictions[$row->pr_type] )
2755                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2756                                         ) {
2757                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2758                                         }
2759                                 } else {
2760                                         $sources = true;
2761                                 }
2762                         }
2763                 }
2764
2765                 if ( $getPages ) {
2766                         $this->mCascadeSources = $sources;
2767                         $this->mCascadingRestrictions = $pagerestrictions;
2768                 } else {
2769                         $this->mHasCascadingRestrictions = $sources;
2770                 }
2771
2772                 return [ $sources, $pagerestrictions ];
2773         }
2774
2775         /**
2776          * Accessor for mRestrictionsLoaded
2777          *
2778          * @return bool Whether or not the page's restrictions have already been
2779          * loaded from the database
2780          * @since 1.23
2781          */
2782         public function areRestrictionsLoaded() {
2783                 return $this->mRestrictionsLoaded;
2784         }
2785
2786         /**
2787          * Accessor/initialisation for mRestrictions
2788          *
2789          * @param string $action Action that permission needs to be checked for
2790          * @return array Restriction levels needed to take the action. All levels are
2791          *     required. Note that restriction levels are normally user rights, but 'sysop'
2792          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2793          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2794          */
2795         public function getRestrictions( $action ) {
2796                 if ( !$this->mRestrictionsLoaded ) {
2797                         $this->loadRestrictions();
2798                 }
2799                 return isset( $this->mRestrictions[$action] )
2800                                 ? $this->mRestrictions[$action]
2801                                 : [];
2802         }
2803
2804         /**
2805          * Accessor/initialisation for mRestrictions
2806          *
2807          * @return array Keys are actions, values are arrays as returned by
2808          *     Title::getRestrictions()
2809          * @since 1.23
2810          */
2811         public function getAllRestrictions() {
2812                 if ( !$this->mRestrictionsLoaded ) {
2813                         $this->loadRestrictions();
2814                 }
2815                 return $this->mRestrictions;
2816         }
2817
2818         /**
2819          * Get the expiry time for the restriction against a given action
2820          *
2821          * @param string $action
2822          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2823          *     or not protected at all, or false if the action is not recognised.
2824          */
2825         public function getRestrictionExpiry( $action ) {
2826                 if ( !$this->mRestrictionsLoaded ) {
2827                         $this->loadRestrictions();
2828                 }
2829                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2830         }
2831
2832         /**
2833          * Returns cascading restrictions for the current article
2834          *
2835          * @return bool
2836          */
2837         function areRestrictionsCascading() {
2838                 if ( !$this->mRestrictionsLoaded ) {
2839                         $this->loadRestrictions();
2840                 }
2841
2842                 return $this->mCascadeRestriction;
2843         }
2844
2845         /**
2846          * Loads a string into mRestrictions array
2847          *
2848          * @param ResultWrapper $res Resource restrictions as an SQL result.
2849          * @param string $oldFashionedRestrictions Comma-separated list of page
2850          *        restrictions from page table (pre 1.10)
2851          */
2852         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2853                 $rows = [];
2854
2855                 foreach ( $res as $row ) {
2856                         $rows[] = $row;
2857                 }
2858
2859                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2860         }
2861
2862         /**
2863          * Compiles list of active page restrictions from both page table (pre 1.10)
2864          * and page_restrictions table for this existing page.
2865          * Public for usage by LiquidThreads.
2866          *
2867          * @param array $rows Array of db result objects
2868          * @param string $oldFashionedRestrictions Comma-separated list of page
2869          *   restrictions from page table (pre 1.10)
2870          */
2871         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2872                 $dbr = wfGetDB( DB_SLAVE );
2873
2874                 $restrictionTypes = $this->getRestrictionTypes();
2875
2876                 foreach ( $restrictionTypes as $type ) {
2877                         $this->mRestrictions[$type] = [];
2878                         $this->mRestrictionsExpiry[$type] = 'infinity';
2879                 }
2880
2881                 $this->mCascadeRestriction = false;
2882
2883                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2884                 if ( $oldFashionedRestrictions !== null ) {
2885                         $this->mOldRestrictions = $oldFashionedRestrictions;
2886                 }
2887
2888                 if ( $this->mOldRestrictions === false ) {
2889                         $this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2890                                 [ 'page_id' => $this->getArticleID() ], __METHOD__ );
2891                 }
2892
2893                 if ( $this->mOldRestrictions != '' ) {
2894                         foreach ( explode( ':', trim( $this->mOldRestrictions ) ) as $restrict ) {
2895                                 $temp = explode( '=', trim( $restrict ) );
2896                                 if ( count( $temp ) == 1 ) {
2897                                         // old old format should be treated as edit/move restriction
2898                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2899                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2900                                 } else {
2901                                         $restriction = trim( $temp[1] );
2902                                         if ( $restriction != '' ) { // some old entries are empty
2903                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2904                                         }
2905                                 }
2906                         }
2907                 }
2908
2909                 if ( count( $rows ) ) {
2910                         # Current system - load second to make them override.
2911                         $now = wfTimestampNow();
2912
2913                         # Cycle through all the restrictions.
2914                         foreach ( $rows as $row ) {
2915
2916                                 // Don't take care of restrictions types that aren't allowed
2917                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2918                                         continue;
2919                                 }
2920
2921                                 // This code should be refactored, now that it's being used more generally,
2922                                 // But I don't really see any harm in leaving it in Block for now -werdna
2923                                 $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2924
2925                                 // Only apply the restrictions if they haven't expired!
2926                                 if ( !$expiry || $expiry > $now ) {
2927                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2928                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2929
2930                                         $this->mCascadeRestriction |= $row->pr_cascade;
2931                                 }
2932                         }
2933                 }
2934
2935                 $this->mRestrictionsLoaded = true;
2936         }
2937
2938         /**
2939          * Load restrictions from the page_restrictions table
2940          *
2941          * @param string $oldFashionedRestrictions Comma-separated list of page
2942          *   restrictions from page table (pre 1.10)
2943          */
2944         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2945                 if ( !$this->mRestrictionsLoaded ) {
2946                         $dbr = wfGetDB( DB_SLAVE );
2947                         if ( $this->exists() ) {
2948                                 $res = $dbr->select(
2949                                         'page_restrictions',
2950                                         [ 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ],
2951                                         [ 'pr_page' => $this->getArticleID() ],
2952                                         __METHOD__
2953                                 );
2954
2955                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2956                         } else {
2957                                 $title_protection = $this->getTitleProtection();
2958
2959                                 if ( $title_protection ) {
2960                                         $now = wfTimestampNow();
2961                                         $expiry = $dbr->decodeExpiry( $title_protection['expiry'] );
2962
2963                                         if ( !$expiry || $expiry > $now ) {
2964                                                 // Apply the restrictions
2965                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2966                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
2967                                         } else { // Get rid of the old restrictions
2968                                                 $this->mTitleProtection = false;
2969                                         }
2970                                 } else {
2971                                         $this->mRestrictionsExpiry['create'] = 'infinity';
2972                                 }
2973                                 $this->mRestrictionsLoaded = true;
2974                         }
2975                 }
2976         }
2977
2978         /**
2979          * Flush the protection cache in this object and force reload from the database.
2980          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2981          */
2982         public function flushRestrictions() {
2983                 $this->mRestrictionsLoaded = false;
2984                 $this->mTitleProtection = null;
2985         }
2986
2987         /**
2988          * Purge expired restrictions from the page_restrictions table
2989          *
2990          * This will purge no more than $wgUpdateRowsPerQuery page_restrictions rows
2991          */
2992         static function purgeExpiredRestrictions() {
2993                 if ( wfReadOnly() ) {
2994                         return;
2995                 }
2996
2997                 DeferredUpdates::addUpdate( new AtomicSectionUpdate(
2998                         wfGetDB( DB_MASTER ),
2999                         __METHOD__,
3000                         function ( IDatabase $dbw, $fname ) {
3001                                 $config = MediaWikiServices::getInstance()->getMainConfig();
3002                                 $ids = $dbw->selectFieldValues(
3003                                         'page_restrictions',
3004                                         'pr_id',
3005                                         [ 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ],
3006                                         $fname,
3007                                         [ 'LIMIT' => $config->get( 'UpdateRowsPerQuery' ) ] // T135470
3008                                 );
3009                                 if ( $ids ) {
3010                                         $dbw->delete( 'page_restrictions', [ 'pr_id' => $ids ], $fname );
3011                                 }
3012                         }
3013                 ) );
3014
3015                 DeferredUpdates::addUpdate( new AtomicSectionUpdate(
3016                         wfGetDB( DB_MASTER ),
3017                         __METHOD__,
3018                         function ( IDatabase $dbw, $fname ) {
3019                                 $dbw->delete(
3020                                         'protected_titles',
3021                                         [ 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ],
3022                                         $fname
3023                                 );
3024                         }
3025                 ) );
3026         }
3027
3028         /**
3029          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3030          *
3031          * @return bool
3032          */
3033         public function hasSubpages() {
3034                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3035                         # Duh
3036                         return false;
3037                 }
3038
3039                 # We dynamically add a member variable for the purpose of this method
3040                 # alone to cache the result.  There's no point in having it hanging
3041                 # around uninitialized in every Title object; therefore we only add it
3042                 # if needed and don't declare it statically.
3043                 if ( $this->mHasSubpages === null ) {
3044                         $this->mHasSubpages = false;
3045                         $subpages = $this->getSubpages( 1 );
3046                         if ( $subpages instanceof TitleArray ) {
3047                                 $this->mHasSubpages = (bool)$subpages->count();
3048                         }
3049                 }
3050
3051                 return $this->mHasSubpages;
3052         }
3053
3054         /**
3055          * Get all subpages of this page.
3056          *
3057          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3058          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3059          *  doesn't allow subpages
3060          */
3061         public function getSubpages( $limit = -1 ) {
3062                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3063                         return [];
3064                 }
3065
3066                 $dbr = wfGetDB( DB_SLAVE );
3067                 $conds['page_namespace'] = $this->getNamespace();
3068                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3069                 $options = [];
3070                 if ( $limit > -1 ) {
3071                         $options['LIMIT'] = $limit;
3072                 }
3073                 $this->mSubpages = TitleArray::newFromResult(
3074                         $dbr->select( 'page',
3075                                 [ 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ],
3076                                 $conds,
3077                                 __METHOD__,
3078                                 $options
3079                         )
3080                 );
3081                 return $this->mSubpages;
3082         }
3083
3084         /**
3085          * Is there a version of this page in the deletion archive?
3086          *
3087          * @return int The number of archived revisions
3088          */
3089         public function isDeleted() {
3090                 if ( $this->getNamespace() < 0 ) {
3091                         $n = 0;
3092                 } else {
3093                         $dbr = wfGetDB( DB_SLAVE );
3094
3095                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3096                                 [ 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ],
3097                                 __METHOD__
3098                         );
3099                         if ( $this->getNamespace() == NS_FILE ) {
3100                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3101                                         [ 'fa_name' => $this->getDBkey() ],
3102                                         __METHOD__
3103                                 );
3104                         }
3105                 }
3106                 return (int)$n;
3107         }
3108
3109         /**
3110          * Is there a version of this page in the deletion archive?
3111          *
3112          * @return bool
3113          */
3114         public function isDeletedQuick() {
3115                 if ( $this->getNamespace() < 0 ) {
3116                         return false;
3117                 }
3118                 $dbr = wfGetDB( DB_SLAVE );
3119                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3120                         [ 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ],
3121                         __METHOD__
3122                 );
3123                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3124                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3125                                 [ 'fa_name' => $this->getDBkey() ],
3126                                 __METHOD__
3127                         );
3128                 }
3129                 return $deleted;
3130         }
3131
3132         /**
3133          * Get the article ID for this Title from the link cache,
3134          * adding it if necessary
3135          *
3136          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3137          *  for update
3138          * @return int The ID
3139          */
3140         public function getArticleID( $flags = 0 ) {
3141                 if ( $this->getNamespace() < 0 ) {
3142                         $this->mArticleID = 0;
3143                         return $this->mArticleID;
3144                 }
3145                 $linkCache = LinkCache::singleton();
3146                 if ( $flags & self::GAID_FOR_UPDATE ) {
3147                         $oldUpdate = $linkCache->forUpdate( true );
3148                         $linkCache->clearLink( $this );
3149                         $this->mArticleID = $linkCache->addLinkObj( $this );
3150                         $linkCache->forUpdate( $oldUpdate );
3151                 } else {
3152                         if ( -1 == $this->mArticleID ) {
3153                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3154                         }
3155                 }
3156                 return $this->mArticleID;
3157         }
3158
3159         /**
3160          * Is this an article that is a redirect page?
3161          * Uses link cache, adding it if necessary
3162          *
3163          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3164          * @return bool
3165          */
3166         public function isRedirect( $flags = 0 ) {
3167                 if ( !is_null( $this->mRedirect ) ) {
3168                         return $this->mRedirect;
3169                 }
3170                 if ( !$this->getArticleID( $flags ) ) {
3171                         $this->mRedirect = false;
3172                         return $this->mRedirect;
3173                 }
3174
3175                 $linkCache = LinkCache::singleton();
3176                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3177                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3178                 if ( $cached === null ) {
3179                         # Trust LinkCache's state over our own
3180                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3181                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3182                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3183                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3184                         # LinkCache to refresh its data from the master.
3185                         $this->mRedirect = false;
3186                         return $this->mRedirect;
3187                 }
3188
3189                 $this->mRedirect = (bool)$cached;
3190
3191                 return $this->mRedirect;
3192         }
3193
3194         /**
3195          * What is the length of this page?
3196          * Uses link cache, adding it if necessary
3197          *
3198          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3199          * @return int
3200          */
3201         public function getLength( $flags = 0 ) {
3202                 if ( $this->mLength != -1 ) {
3203                         return $this->mLength;
3204                 }
3205                 if ( !$this->getArticleID( $flags ) ) {
3206                         $this->mLength = 0;
3207                         return $this->mLength;
3208                 }
3209                 $linkCache = LinkCache::singleton();
3210                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3211                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3212                 if ( $cached === null ) {
3213                         # Trust LinkCache's state over our own, as for isRedirect()
3214                         $this->mLength = 0;
3215                         return $this->mLength;
3216                 }
3217
3218                 $this->mLength = intval( $cached );
3219
3220                 return $this->mLength;
3221         }
3222
3223         /**
3224          * What is the page_latest field for this page?
3225          *
3226          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3227          * @return int Int or 0 if the page doesn't exist
3228          */
3229         public function getLatestRevID( $flags = 0 ) {
3230                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3231                         return intval( $this->mLatestID );
3232                 }
3233                 if ( !$this->getArticleID( $flags ) ) {
3234                         $this->mLatestID = 0;
3235                         return $this->mLatestID;
3236                 }
3237                 $linkCache = LinkCache::singleton();
3238                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3239                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3240                 if ( $cached === null ) {
3241                         # Trust LinkCache's state over our own, as for isRedirect()
3242                         $this->mLatestID = 0;
3243                         return $this->mLatestID;
3244                 }
3245
3246                 $this->mLatestID = intval( $cached );
3247
3248                 return $this->mLatestID;
3249         }
3250
3251         /**
3252          * This clears some fields in this object, and clears any associated
3253          * keys in the "bad links" section of the link cache.
3254          *
3255          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3256          * loading of the new page_id. It's also called from
3257          * WikiPage::doDeleteArticleReal()
3258          *
3259          * @param int $newid The new Article ID
3260          */
3261         public function resetArticleID( $newid ) {
3262                 $linkCache = LinkCache::singleton();
3263                 $linkCache->clearLink( $this );
3264
3265                 if ( $newid === false ) {
3266                         $this->mArticleID = -1;
3267                 } else {
3268                         $this->mArticleID = intval( $newid );
3269                 }
3270                 $this->mRestrictionsLoaded = false;
3271                 $this->mRestrictions = [];
3272                 $this->mOldRestrictions = false;
3273                 $this->mRedirect = null;
3274                 $this->mLength = -1;
3275                 $this->mLatestID = false;
3276                 $this->mContentModel = false;
3277                 $this->mEstimateRevisions = null;
3278                 $this->mPageLanguage = false;
3279                 $this->mDbPageLanguage = false;
3280                 $this->mIsBigDeletion = null;
3281         }
3282
3283         public static function clearCaches() {
3284                 $linkCache = LinkCache::singleton();
3285                 $linkCache->clear();
3286
3287                 $titleCache = self::getTitleCache();
3288                 $titleCache->clear();
3289         }
3290
3291         /**
3292          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3293          *
3294          * @param string $text Containing title to capitalize
3295          * @param int $ns Namespace index, defaults to NS_MAIN
3296          * @return string Containing capitalized title
3297          */
3298         public static function capitalize( $text, $ns = NS_MAIN ) {
3299                 global $wgContLang;
3300
3301                 if ( MWNamespace::isCapitalized( $ns ) ) {
3302                         return $wgContLang->ucfirst( $text );
3303                 } else {
3304                         return $text;
3305                 }
3306         }
3307
3308         /**
3309          * Secure and split - main initialisation function for this object
3310          *
3311          * Assumes that mDbkeyform has been set, and is urldecoded
3312          * and uses underscores, but not otherwise munged.  This function
3313          * removes illegal characters, splits off the interwiki and
3314          * namespace prefixes, sets the other forms, and canonicalizes
3315          * everything.
3316          *
3317          * @throws MalformedTitleException On invalid titles
3318          * @return bool True on success
3319          */
3320         private function secureAndSplit() {
3321                 # Initialisation
3322                 $this->mInterwiki = '';
3323                 $this->mFragment = '';
3324                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3325
3326                 $dbkey = $this->mDbkeyform;
3327
3328                 // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3329                 //        the parsing code with Title, while avoiding massive refactoring.
3330                 // @todo: get rid of secureAndSplit, refactor parsing code.
3331                 // @note: getTitleParser() returns a TitleParser implementation which does not have a
3332                 //        splitTitleString method, but the only implementation (MediaWikiTitleCodec) does
3333                 $titleCodec = MediaWikiServices::getInstance()->getTitleParser();
3334                 // MalformedTitleException can be thrown here
3335                 $parts = $titleCodec->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3336
3337                 # Fill fields
3338                 $this->setFragment( '#' . $parts['fragment'] );
3339                 $this->mInterwiki = $parts['interwiki'];
3340                 $this->mLocalInterwiki = $parts['local_interwiki'];
3341                 $this->mNamespace = $parts['namespace'];
3342                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3343
3344                 $this->mDbkeyform = $parts['dbkey'];
3345                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3346                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
3347
3348                 # We already know that some pages won't be in the database!
3349                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3350                         $this->mArticleID = 0;
3351                 }
3352
3353                 return true;
3354         }
3355
3356         /**
3357          * Get an array of Title objects linking to this Title
3358          * Also stores the IDs in the link cache.
3359          *
3360          * WARNING: do not use this function on arbitrary user-supplied titles!
3361          * On heavily-used templates it will max out the memory.
3362          *
3363          * @param array $options May be FOR UPDATE
3364          * @param string $table Table name
3365          * @param string $prefix Fields prefix
3366          * @return Title[] Array of Title objects linking here
3367          */
3368         public function getLinksTo( $options = [], $table = 'pagelinks', $prefix = 'pl' ) {
3369                 if ( count( $options ) > 0 ) {
3370                         $db = wfGetDB( DB_MASTER );
3371                 } else {
3372                         $db = wfGetDB( DB_SLAVE );
3373                 }
3374
3375                 $res = $db->select(
3376                         [ 'page', $table ],
3377                         self::getSelectFields(),
3378                         [
3379                                 "{$prefix}_from=page_id",
3380                                 "{$prefix}_namespace" => $this->getNamespace(),
3381                                 "{$prefix}_title" => $this->getDBkey() ],
3382                         __METHOD__,
3383                         $options
3384                 );
3385
3386                 $retVal = [];
3387                 if ( $res->numRows() ) {
3388                         $linkCache = LinkCache::singleton();
3389                         foreach ( $res as $row ) {
3390                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3391                                 if ( $titleObj ) {
3392                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3393                                         $retVal[] = $titleObj;
3394                                 }
3395                         }
3396                 }
3397                 return $retVal;
3398         }
3399
3400         /**
3401          * Get an array of Title objects using this Title as a template
3402          * Also stores the IDs in the link cache.
3403          *
3404          * WARNING: do not use this function on arbitrary user-supplied titles!
3405          * On heavily-used templates it will max out the memory.
3406          *
3407          * @param array $options Query option to Database::select()
3408          * @return Title[] Array of Title the Title objects linking here
3409          */
3410         public function getTemplateLinksTo( $options = [] ) {
3411                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3412         }
3413
3414         /**
3415          * Get an array of Title objects linked from this Title
3416          * Also stores the IDs in the link cache.
3417          *
3418          * WARNING: do not use this function on arbitrary user-supplied titles!
3419          * On heavily-used templates it will max out the memory.
3420          *
3421          * @param array $options Query option to Database::select()
3422          * @param string $table Table name
3423          * @param string $prefix Fields prefix
3424          * @return array Array of Title objects linking here
3425          */
3426         public function getLinksFrom( $options = [], $table = 'pagelinks', $prefix = 'pl' ) {
3427                 $id = $this->getArticleID();
3428
3429                 # If the page doesn't exist; there can't be any link from this page
3430                 if ( !$id ) {
3431                         return [];
3432                 }
3433
3434                 $db = wfGetDB( DB_SLAVE );
3435
3436                 $blNamespace = "{$prefix}_namespace";
3437                 $blTitle = "{$prefix}_title";
3438
3439                 $res = $db->select(
3440                         [ $table, 'page' ],
3441                         array_merge(
3442                                 [ $blNamespace, $blTitle ],
3443                                 WikiPage::selectFields()
3444                         ),
3445                         [ "{$prefix}_from" => $id ],
3446                         __METHOD__,
3447                         $options,
3448                         [ 'page' => [
3449                                 'LEFT JOIN',
3450                                 [ "page_namespace=$blNamespace", "page_title=$blTitle" ]
3451                         ] ]
3452                 );
3453
3454                 $retVal = [];
3455                 $linkCache = LinkCache::singleton();
3456                 foreach ( $res as $row ) {
3457                         if ( $row->page_id ) {
3458                                 $titleObj = Title::newFromRow( $row );
3459                         } else {
3460                                 $titleObj = Title::makeTitle( $row->$blNamespace, $row->$blTitle );
3461                                 $linkCache->addBadLinkObj( $titleObj );
3462                         }
3463                         $retVal[] = $titleObj;
3464                 }
3465
3466                 return $retVal;
3467         }
3468
3469         /**
3470          * Get an array of Title objects used on this Title as a template
3471          * Also stores the IDs in the link cache.
3472          *
3473          * WARNING: do not use this function on arbitrary user-supplied titles!
3474          * On heavily-used templates it will max out the memory.
3475          *
3476          * @param array $options May be FOR UPDATE
3477          * @return Title[] Array of Title the Title objects used here
3478          */
3479         public function getTemplateLinksFrom( $options = [] ) {
3480                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3481         }
3482
3483         /**
3484          * Get an array of Title objects referring to non-existent articles linked
3485          * from this page.
3486          *
3487          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3488          *   should use redirect table in this case).
3489          * @return Title[] Array of Title the Title objects
3490          */
3491         public function getBrokenLinksFrom() {
3492                 if ( $this->getArticleID() == 0 ) {
3493                         # All links from article ID 0 are false positives
3494                         return [];
3495                 }
3496
3497                 $dbr = wfGetDB( DB_SLAVE );
3498                 $res = $dbr->select(
3499                         [ 'page', 'pagelinks' ],
3500                         [ 'pl_namespace', 'pl_title' ],
3501                         [
3502                                 'pl_from' => $this->getArticleID(),
3503                                 'page_namespace IS NULL'
3504                         ],
3505                         __METHOD__, [],
3506                         [
3507                                 'page' => [
3508                                         'LEFT JOIN',
3509                                         [ 'pl_namespace=page_namespace', 'pl_title=page_title' ]
3510                                 ]
3511                         ]
3512                 );
3513
3514                 $retVal = [];
3515                 foreach ( $res as $row ) {
3516                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3517                 }
3518                 return $retVal;
3519         }
3520
3521         /**
3522          * Get a list of URLs to purge from the CDN cache when this
3523          * page changes
3524          *
3525          * @return string[] Array of String the URLs
3526          */
3527         public function getCdnUrls() {
3528                 $urls = [
3529                         $this->getInternalURL(),
3530                         $this->getInternalURL( 'action=history' )
3531                 ];
3532
3533                 $pageLang = $this->getPageLanguage();
3534                 if ( $pageLang->hasVariants() ) {
3535                         $variants = $pageLang->getVariants();
3536                         foreach ( $variants as $vCode ) {
3537                                 $urls[] = $this->getInternalURL( $vCode );
3538                         }
3539                 }
3540
3541                 // If we are looking at a css/js user subpage, purge the action=raw.
3542                 if ( $this->isJsSubpage() ) {
3543                         $urls[] = $this->getInternalURL( 'action=raw&ctype=text/javascript' );
3544                 } elseif ( $this->isCssSubpage() ) {
3545                         $urls[] = $this->getInternalURL( 'action=raw&ctype=text/css' );
3546                 }
3547
3548                 Hooks::run( 'TitleSquidURLs', [ $this, &$urls ] );
3549                 return $urls;
3550         }
3551
3552         /**
3553          * @deprecated since 1.27 use getCdnUrls()
3554          */
3555         public function getSquidURLs() {
3556                 return $this->getCdnUrls();
3557         }
3558
3559         /**
3560          * Purge all applicable CDN URLs
3561          */
3562         public function purgeSquid() {
3563                 DeferredUpdates::addUpdate(
3564                         new CdnCacheUpdate( $this->getCdnUrls() ),
3565                         DeferredUpdates::PRESEND
3566                 );
3567         }
3568
3569         /**
3570          * Move this page without authentication
3571          *
3572          * @deprecated since 1.25 use MovePage class instead
3573          * @param Title $nt The new page Title
3574          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3575          */
3576         public function moveNoAuth( &$nt ) {
3577                 wfDeprecated( __METHOD__, '1.25' );
3578                 return $this->moveTo( $nt, false );
3579         }
3580
3581         /**
3582          * Check whether a given move operation would be valid.
3583          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3584          *
3585          * @deprecated since 1.25, use MovePage's methods instead
3586          * @param Title $nt The new title
3587          * @param bool $auth Whether to check user permissions (uses $wgUser)
3588          * @param string $reason Is the log summary of the move, used for spam checking
3589          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3590          */
3591         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3592                 global $wgUser;
3593
3594                 if ( !( $nt instanceof Title ) ) {
3595                         // Normally we'd add this to $errors, but we'll get
3596                         // lots of syntax errors if $nt is not an object
3597                         return [ [ 'badtitletext' ] ];
3598                 }
3599
3600                 $mp = new MovePage( $this, $nt );
3601                 $errors = $mp->isValidMove()->getErrorsArray();
3602                 if ( $auth ) {
3603                         $errors = wfMergeErrorArrays(
3604                                 $errors,
3605                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3606                         );
3607                 }
3608
3609                 return $errors ?: true;
3610         }
3611
3612         /**
3613          * Check if the requested move target is a valid file move target
3614          * @todo move this to MovePage
3615          * @param Title $nt Target title
3616          * @return array List of errors
3617          */
3618         protected function validateFileMoveOperation( $nt ) {
3619                 global $wgUser;
3620
3621                 $errors = [];
3622
3623                 $destFile = wfLocalFile( $nt );
3624                 $destFile->load( File::READ_LATEST );
3625                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3626                         && !$destFile->exists() && wfFindFile( $nt )
3627                 ) {
3628                         $errors[] = [ 'file-exists-sharedrepo' ];
3629                 }
3630
3631                 return $errors;
3632         }
3633
3634         /**
3635          * Move a title to a new location
3636          *
3637          * @deprecated since 1.25, use the MovePage class instead
3638          * @param Title $nt The new title
3639          * @param bool $auth Indicates whether $wgUser's permissions
3640          *  should be checked
3641          * @param string $reason The reason for the move
3642          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3643          *  Ignored if the user doesn't have the suppressredirect right.
3644          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3645          */
3646         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3647                 global $wgUser;
3648                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3649                 if ( is_array( $err ) ) {
3650                         // Auto-block user's IP if the account was "hard" blocked
3651                         $wgUser->spreadAnyEditBlock();
3652                         return $err;
3653                 }
3654                 // Check suppressredirect permission
3655                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3656                         $createRedirect = true;
3657                 }
3658
3659                 $mp = new MovePage( $this, $nt );
3660                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3661                 if ( $status->isOK() ) {
3662                         return true;
3663                 } else {
3664                         return $status->getErrorsArray();
3665                 }
3666         }
3667
3668         /**
3669          * Move this page's subpages to be subpages of $nt
3670          *
3671          * @param Title $nt Move target
3672          * @param bool $auth Whether $wgUser's permissions should be checked
3673          * @param string $reason The reason for the move
3674          * @param bool $createRedirect Whether to create redirects from the old subpages to
3675          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3676          * @return array Array with old page titles as keys, and strings (new page titles) or
3677          *     arrays (errors) as values, or an error array with numeric indices if no pages
3678          *     were moved
3679          */
3680         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3681                 global $wgMaximumMovedPages;
3682                 // Check permissions
3683                 if ( !$this->userCan( 'move-subpages' ) ) {
3684                         return [ 'cant-move-subpages' ];
3685                 }
3686                 // Do the source and target namespaces support subpages?
3687                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3688                         return [ 'namespace-nosubpages',
3689                                 MWNamespace::getCanonicalName( $this->getNamespace() ) ];
3690                 }
3691                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3692                         return [ 'namespace-nosubpages',
3693                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) ];
3694                 }
3695
3696                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3697                 $retval = [];
3698                 $count = 0;
3699                 foreach ( $subpages as $oldSubpage ) {
3700                         $count++;
3701                         if ( $count > $wgMaximumMovedPages ) {
3702                                 $retval[$oldSubpage->getPrefixedText()] =
3703                                                 [ 'movepage-max-pages',
3704                                                         $wgMaximumMovedPages ];
3705                                 break;
3706                         }
3707
3708                         // We don't know whether this function was called before
3709                         // or after moving the root page, so check both
3710                         // $this and $nt
3711                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3712                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3713                         ) {
3714                                 // When moving a page to a subpage of itself,
3715                                 // don't move it twice
3716                                 continue;
3717                         }
3718                         $newPageName = preg_replace(
3719                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3720                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3721                                         $oldSubpage->getDBkey() );
3722                         if ( $oldSubpage->isTalkPage() ) {
3723                                 $newNs = $nt->getTalkPage()->getNamespace();
3724                         } else {
3725                                 $newNs = $nt->getSubjectPage()->getNamespace();
3726                         }
3727                         # Bug 14385: we need makeTitleSafe because the new page names may
3728                         # be longer than 255 characters.
3729                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3730
3731                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3732                         if ( $success === true ) {
3733                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3734                         } else {
3735                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3736                         }
3737                 }
3738                 return $retval;
3739         }
3740
3741         /**
3742          * Checks if this page is just a one-rev redirect.
3743          * Adds lock, so don't use just for light purposes.
3744          *
3745          * @return bool
3746          */
3747         public function isSingleRevRedirect() {
3748                 global $wgContentHandlerUseDB;
3749
3750                 $dbw = wfGetDB( DB_MASTER );
3751
3752                 # Is it a redirect?
3753                 $fields = [ 'page_is_redirect', 'page_latest', 'page_id' ];
3754                 if ( $wgContentHandlerUseDB ) {
3755                         $fields[] = 'page_content_model';
3756                 }
3757
3758                 $row = $dbw->selectRow( 'page',
3759                         $fields,
3760                         $this->pageCond(),
3761                         __METHOD__,
3762                         [ 'FOR UPDATE' ]
3763                 );
3764                 # Cache some fields we may want
3765                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3766                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3767                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3768                 $this->mContentModel = $row && isset( $row->page_content_model )
3769                         ? strval( $row->page_content_model )
3770                         : false;
3771
3772                 if ( !$this->mRedirect ) {
3773                         return false;
3774                 }
3775                 # Does the article have a history?
3776                 $row = $dbw->selectField( [ 'page', 'revision' ],
3777                         'rev_id',
3778                         [ 'page_namespace' => $this->getNamespace(),
3779                                 'page_title' => $this->getDBkey(),
3780                                 'page_id=rev_page',
3781                                 'page_latest != rev_id'
3782                         ],
3783                         __METHOD__,
3784                         [ 'FOR UPDATE' ]
3785                 );
3786                 # Return true if there was no history
3787                 return ( $row === false );
3788         }
3789
3790         /**
3791          * Checks if $this can be moved to a given Title
3792          * - Selects for update, so don't call it unless you mean business
3793          *
3794          * @deprecated since 1.25, use MovePage's methods instead
3795          * @param Title $nt The new title to check
3796          * @return bool
3797          */
3798         public function isValidMoveTarget( $nt ) {
3799                 # Is it an existing file?
3800                 if ( $nt->getNamespace() == NS_FILE ) {
3801                         $file = wfLocalFile( $nt );
3802                         $file->load( File::READ_LATEST );
3803                         if ( $file->exists() ) {
3804                                 wfDebug( __METHOD__ . ": file exists\n" );
3805                                 return false;
3806                         }
3807                 }
3808                 # Is it a redirect with no history?
3809                 if ( !$nt->isSingleRevRedirect() ) {
3810                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3811                         return false;
3812                 }
3813                 # Get the article text
3814                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3815                 if ( !is_object( $rev ) ) {
3816                         return false;
3817                 }
3818                 $content = $rev->getContent();
3819                 # Does the redirect point to the source?
3820                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3821                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3822
3823                 if ( $redirTitle ) {
3824                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3825                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3826                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3827                                 return false;
3828                         } else {
3829                                 return true;
3830                         }
3831                 } else {
3832                         # Fail safe (not a redirect after all. strange.)
3833                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3834                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3835                         return false;
3836                 }
3837         }
3838
3839         /**
3840          * Get categories to which this Title belongs and return an array of
3841          * categories' names.
3842          *
3843          * @return array Array of parents in the form:
3844          *        $parent => $currentarticle
3845          */
3846         public function getParentCategories() {
3847                 global $wgContLang;
3848
3849                 $data = [];
3850
3851                 $titleKey = $this->getArticleID();
3852
3853                 if ( $titleKey === 0 ) {
3854                         return $data;
3855                 }
3856
3857                 $dbr = wfGetDB( DB_SLAVE );
3858
3859                 $res = $dbr->select(
3860                         'categorylinks',
3861                         'cl_to',
3862                         [ 'cl_from' => $titleKey ],
3863                         __METHOD__
3864                 );
3865
3866                 if ( $res->numRows() > 0 ) {
3867                         foreach ( $res as $row ) {
3868                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3869                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3870                         }
3871                 }
3872                 return $data;
3873         }
3874
3875         /**
3876          * Get a tree of parent categories
3877          *
3878          * @param array $children Array with the children in the keys, to check for circular refs
3879          * @return array Tree of parent categories
3880          */
3881         public function getParentCategoryTree( $children = [] ) {
3882                 $stack = [];
3883                 $parents = $this->getParentCategories();
3884
3885                 if ( $parents ) {
3886                         foreach ( $parents as $parent => $current ) {
3887                                 if ( array_key_exists( $parent, $children ) ) {
3888                                         # Circular reference
3889                                         $stack[$parent] = [];
3890                                 } else {
3891                                         $nt = Title::newFromText( $parent );
3892                                         if ( $nt ) {
3893                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + [ $parent => 1 ] );
3894                                         }
3895                                 }
3896                         }
3897                 }
3898
3899                 return $stack;
3900         }
3901
3902         /**
3903          * Get an associative array for selecting this title from
3904          * the "page" table
3905          *
3906          * @return array Array suitable for the $where parameter of DB::select()
3907          */
3908         public function pageCond() {
3909                 if ( $this->mArticleID > 0 ) {
3910                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3911                         return [ 'page_id' => $this->mArticleID ];
3912                 } else {
3913                         return [ 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform ];
3914                 }
3915         }
3916
3917         /**
3918          * Get the revision ID of the previous revision
3919          *
3920          * @param int $revId Revision ID. Get the revision that was before this one.
3921          * @param int $flags Title::GAID_FOR_UPDATE
3922          * @return int|bool Old revision ID, or false if none exists
3923          */
3924         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3925                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3926                 $revId = $db->selectField( 'revision', 'rev_id',
3927                         [
3928                                 'rev_page' => $this->getArticleID( $flags ),
3929                                 'rev_id < ' . intval( $revId )
3930                         ],
3931                         __METHOD__,
3932                         [ 'ORDER BY' => 'rev_id DESC' ]
3933                 );
3934
3935                 if ( $revId === false ) {
3936                         return false;
3937                 } else {
3938                         return intval( $revId );
3939                 }
3940         }
3941
3942         /**
3943          * Get the revision ID of the next revision
3944          *
3945          * @param int $revId Revision ID. Get the revision that was after this one.
3946          * @param int $flags Title::GAID_FOR_UPDATE
3947          * @return int|bool Next revision ID, or false if none exists
3948          */
3949         public function getNextRevisionID( $revId, $flags = 0 ) {
3950                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3951                 $revId = $db->selectField( 'revision', 'rev_id',
3952                         [
3953                                 'rev_page' => $this->getArticleID( $flags ),
3954                                 'rev_id > ' . intval( $revId )
3955                         ],
3956                         __METHOD__,
3957                         [ 'ORDER BY' => 'rev_id' ]
3958                 );
3959
3960                 if ( $revId === false ) {
3961                         return false;
3962                 } else {
3963                         return intval( $revId );
3964                 }
3965         }
3966
3967         /**
3968          * Get the first revision of the page
3969          *
3970          * @param int $flags Title::GAID_FOR_UPDATE
3971          * @return Revision|null If page doesn't exist
3972          */
3973         public function getFirstRevision( $flags = 0 ) {
3974                 $pageId = $this->getArticleID( $flags );
3975                 if ( $pageId ) {
3976                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3977                         $row = $db->selectRow( 'revision', Revision::selectFields(),
3978                                 [ 'rev_page' => $pageId ],
3979                                 __METHOD__,
3980                                 [ 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 ]
3981                         );
3982                         if ( $row ) {
3983                                 return new Revision( $row );
3984                         }
3985                 }
3986                 return null;
3987         }
3988
3989         /**
3990          * Get the oldest revision timestamp of this page
3991          *
3992          * @param int $flags Title::GAID_FOR_UPDATE
3993          * @return string MW timestamp
3994          */
3995         public function getEarliestRevTime( $flags = 0 ) {
3996                 $rev = $this->getFirstRevision( $flags );
3997                 return $rev ? $rev->getTimestamp() : null;
3998         }
3999
4000         /**
4001          * Check if this is a new page
4002          *
4003          * @return bool
4004          */
4005         public function isNewPage() {
4006                 $dbr = wfGetDB( DB_SLAVE );
4007                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4008         }
4009
4010         /**
4011          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4012          *
4013          * @return bool
4014          */
4015         public function isBigDeletion() {
4016                 global $wgDeleteRevisionsLimit;
4017
4018                 if ( !$wgDeleteRevisionsLimit ) {
4019                         return false;
4020                 }
4021
4022                 if ( $this->mIsBigDeletion === null ) {
4023                         $dbr = wfGetDB( DB_SLAVE );
4024
4025                         $revCount = $dbr->selectRowCount(
4026                                 'revision',
4027                                 '1',
4028                                 [ 'rev_page' => $this->getArticleID() ],
4029                                 __METHOD__,
4030                                 [ 'LIMIT' => $wgDeleteRevisionsLimit + 1 ]
4031                         );
4032
4033                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4034                 }
4035
4036                 return $this->mIsBigDeletion;
4037         }
4038
4039         /**
4040          * Get the approximate revision count of this page.
4041          *
4042          * @return int
4043          */
4044         public function estimateRevisionCount() {
4045                 if ( !$this->exists() ) {
4046                         return 0;
4047                 }
4048
4049                 if ( $this->mEstimateRevisions === null ) {
4050                         $dbr = wfGetDB( DB_SLAVE );
4051                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4052                                 [ 'rev_page' => $this->getArticleID() ], __METHOD__ );
4053                 }
4054
4055                 return $this->mEstimateRevisions;
4056         }
4057
4058         /**
4059          * Get the number of revisions between the given revision.
4060          * Used for diffs and other things that really need it.
4061          *
4062          * @param int|Revision $old Old revision or rev ID (first before range)
4063          * @param int|Revision $new New revision or rev ID (first after range)
4064          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4065          * @return int Number of revisions between these revisions.
4066          */
4067         public function countRevisionsBetween( $old, $new, $max = null ) {
4068                 if ( !( $old instanceof Revision ) ) {
4069                         $old = Revision::newFromTitle( $this, (int)$old );
4070                 }
4071                 if ( !( $new instanceof Revision ) ) {
4072                         $new = Revision::newFromTitle( $this, (int)$new );
4073                 }
4074                 if ( !$old || !$new ) {
4075                         return 0; // nothing to compare
4076                 }
4077                 $dbr = wfGetDB( DB_SLAVE );
4078                 $conds = [
4079                         'rev_page' => $this->getArticleID(),
4080                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4081                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4082                 ];
4083                 if ( $max !== null ) {
4084                         return $dbr->selectRowCount( 'revision', '1',
4085                                 $conds,
4086                                 __METHOD__,
4087                                 [ 'LIMIT' => $max + 1 ] // extra to detect truncation
4088                         );
4089                 } else {
4090                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4091                 }
4092         }
4093
4094         /**
4095          * Get the authors between the given revisions or revision IDs.
4096          * Used for diffs and other things that really need it.
4097          *
4098          * @since 1.23
4099          *
4100          * @param int|Revision $old Old revision or rev ID (first before range by default)
4101          * @param int|Revision $new New revision or rev ID (first after range by default)
4102          * @param int $limit Maximum number of authors
4103          * @param string|array $options (Optional): Single option, or an array of options:
4104          *     'include_old' Include $old in the range; $new is excluded.
4105          *     'include_new' Include $new in the range; $old is excluded.
4106          *     'include_both' Include both $old and $new in the range.
4107          *     Unknown option values are ignored.
4108          * @return array|null Names of revision authors in the range; null if not both revisions exist
4109          */
4110         public function getAuthorsBetween( $old, $new, $limit, $options = [] ) {
4111                 if ( !( $old instanceof Revision ) ) {
4112                         $old = Revision::newFromTitle( $this, (int)$old );
4113                 }
4114                 if ( !( $new instanceof Revision ) ) {
4115                         $new = Revision::newFromTitle( $this, (int)$new );
4116                 }
4117                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4118                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4119                 // in the sanity check below?
4120                 if ( !$old || !$new ) {
4121                         return null; // nothing to compare
4122                 }
4123                 $authors = [];
4124                 $old_cmp = '>';
4125                 $new_cmp = '<';
4126                 $options = (array)$options;
4127                 if ( in_array( 'include_old', $options ) ) {
4128                         $old_cmp = '>=';
4129                 }
4130                 if ( in_array( 'include_new', $options ) ) {
4131                         $new_cmp = '<=';
4132                 }
4133                 if ( in_array( 'include_both', $options ) ) {
4134                         $old_cmp = '>=';
4135                         $new_cmp = '<=';
4136                 }
4137                 // No DB query needed if $old and $new are the same or successive revisions:
4138                 if ( $old->getId() === $new->getId() ) {
4139                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4140                                 [] :
4141                                 [ $old->getUserText( Revision::RAW ) ];
4142                 } elseif ( $old->getId() === $new->getParentId() ) {
4143                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4144                                 $authors[] = $old->getUserText( Revision::RAW );
4145                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4146                                         $authors[] = $new->getUserText( Revision::RAW );
4147                                 }
4148                         } elseif ( $old_cmp === '>=' ) {
4149                                 $authors[] = $old->getUserText( Revision::RAW );
4150                         } elseif ( $new_cmp === '<=' ) {
4151                                 $authors[] = $new->getUserText( Revision::RAW );
4152                         }
4153                         return $authors;
4154                 }
4155                 $dbr = wfGetDB( DB_SLAVE );
4156                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4157                         [
4158                                 'rev_page' => $this->getArticleID(),
4159                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4160                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4161                         ], __METHOD__,
4162                         [ 'LIMIT' => $limit + 1 ] // add one so caller knows it was truncated
4163                 );
4164                 foreach ( $res as $row ) {
4165                         $authors[] = $row->rev_user_text;
4166                 }
4167                 return $authors;
4168         }
4169
4170         /**
4171          * Get the number of authors between the given revisions or revision IDs.
4172          * Used for diffs and other things that really need it.
4173          *
4174          * @param int|Revision $old Old revision or rev ID (first before range by default)
4175          * @param int|Revision $new New revision or rev ID (first after range by default)
4176          * @param int $limit Maximum number of authors
4177          * @param string|array $options (Optional): Single option, or an array of options:
4178          *     'include_old' Include $old in the range; $new is excluded.
4179          *     'include_new' Include $new in the range; $old is excluded.
4180          *     'include_both' Include both $old and $new in the range.
4181          *     Unknown option values are ignored.
4182          * @return int Number of revision authors in the range; zero if not both revisions exist
4183          */
4184         public function countAuthorsBetween( $old, $new, $limit, $options = [] ) {
4185                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4186                 return $authors ? count( $authors ) : 0;
4187         }
4188
4189         /**
4190          * Compare with another title.
4191          *
4192          * @param Title $title
4193          * @return bool
4194          */
4195         public function equals( Title $title ) {
4196                 // Note: === is necessary for proper matching of number-like titles.
4197                 return $this->getInterwiki() === $title->getInterwiki()
4198                         && $this->getNamespace() == $title->getNamespace()
4199                         && $this->getDBkey() === $title->getDBkey();
4200         }
4201
4202         /**
4203          * Check if this title is a subpage of another title
4204          *
4205          * @param Title $title
4206          * @return bool
4207          */
4208         public function isSubpageOf( Title $title ) {
4209                 return $this->getInterwiki() === $title->getInterwiki()
4210                         && $this->getNamespace() == $title->getNamespace()
4211                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4212         }
4213
4214         /**
4215          * Check if page exists.  For historical reasons, this function simply
4216          * checks for the existence of the title in the page table, and will
4217          * thus return false for interwiki links, special pages and the like.
4218          * If you want to know if a title can be meaningfully viewed, you should
4219          * probably call the isKnown() method instead.
4220          *
4221          * @param int $flags An optional bit field; may be Title::GAID_FOR_UPDATE to check
4222          *   from master/for update
4223          * @return bool
4224          */
4225         public function exists( $flags = 0 ) {
4226                 $exists = $this->getArticleID( $flags ) != 0;
4227                 Hooks::run( 'TitleExists', [ $this, &$exists ] );
4228                 return $exists;
4229         }
4230
4231         /**
4232          * Should links to this title be shown as potentially viewable (i.e. as
4233          * "bluelinks"), even if there's no record by this title in the page
4234          * table?
4235          *
4236          * This function is semi-deprecated for public use, as well as somewhat
4237          * misleadingly named.  You probably just want to call isKnown(), which
4238          * calls this function internally.
4239          *
4240          * (ISSUE: Most of these checks are cheap, but the file existence check
4241          * can potentially be quite expensive.  Including it here fixes a lot of
4242          * existing code, but we might want to add an optional parameter to skip
4243          * it and any other expensive checks.)
4244          *
4245          * @return bool
4246          */
4247         public function isAlwaysKnown() {
4248                 $isKnown = null;
4249
4250                 /**
4251                  * Allows overriding default behavior for determining if a page exists.
4252                  * If $isKnown is kept as null, regular checks happen. If it's
4253                  * a boolean, this value is returned by the isKnown method.
4254                  *
4255                  * @since 1.20
4256                  *
4257                  * @param Title $title
4258                  * @param bool|null $isKnown
4259                  */
4260                 Hooks::run( 'TitleIsAlwaysKnown', [ $this, &$isKnown ] );
4261
4262                 if ( !is_null( $isKnown ) ) {
4263                         return $isKnown;
4264                 }
4265
4266                 if ( $this->isExternal() ) {
4267                         return true;  // any interwiki link might be viewable, for all we know
4268                 }
4269
4270                 switch ( $this->mNamespace ) {
4271                         case NS_MEDIA:
4272                         case NS_FILE:
4273                                 // file exists, possibly in a foreign repo
4274                                 return (bool)wfFindFile( $this );
4275                         case NS_SPECIAL:
4276                                 // valid special page
4277                                 return SpecialPageFactory::exists( $this->getDBkey() );
4278                         case NS_MAIN:
4279                                 // selflink, possibly with fragment
4280                                 return $this->mDbkeyform == '';
4281                         case NS_MEDIAWIKI:
4282                                 // known system message
4283                                 return $this->hasSourceText() !== false;
4284                         default:
4285                                 return false;
4286                 }
4287         }
4288
4289         /**
4290          * Does this title refer to a page that can (or might) be meaningfully
4291          * viewed?  In particular, this function may be used to determine if
4292          * links to the title should be rendered as "bluelinks" (as opposed to
4293          * "redlinks" to non-existent pages).
4294          * Adding something else to this function will cause inconsistency
4295          * since LinkHolderArray calls isAlwaysKnown() and does its own
4296          * page existence check.
4297          *
4298          * @return bool
4299          */
4300         public function isKnown() {
4301                 return $this->isAlwaysKnown() || $this->exists();
4302         }
4303
4304         /**
4305          * Does this page have source text?
4306          *
4307          * @return bool
4308          */
4309         public function hasSourceText() {
4310                 if ( $this->exists() ) {
4311                         return true;
4312                 }
4313
4314                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4315                         // If the page doesn't exist but is a known system message, default
4316                         // message content will be displayed, same for language subpages-
4317                         // Use always content language to avoid loading hundreds of languages
4318                         // to get the link color.
4319                         global $wgContLang;
4320                         list( $name, ) = MessageCache::singleton()->figureMessage(
4321                                 $wgContLang->lcfirst( $this->getText() )
4322                         );
4323                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4324                         return $message->exists();
4325                 }
4326
4327                 return false;
4328         }
4329
4330         /**
4331          * Get the default message text or false if the message doesn't exist
4332          *
4333          * @return string|bool
4334          */
4335         public function getDefaultMessageText() {
4336                 global $wgContLang;
4337
4338                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4339                         return false;
4340                 }
4341
4342                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4343                         $wgContLang->lcfirst( $this->getText() )
4344                 );
4345                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4346
4347                 if ( $message->exists() ) {
4348                         return $message->plain();
4349                 } else {
4350                         return false;
4351                 }
4352         }
4353
4354         /**
4355          * Updates page_touched for this page; called from LinksUpdate.php
4356          *
4357          * @param string $purgeTime [optional] TS_MW timestamp
4358          * @return bool True if the update succeeded
4359          */
4360         public function invalidateCache( $purgeTime = null ) {
4361                 if ( wfReadOnly() ) {
4362                         return false;
4363                 }
4364
4365                 if ( $this->mArticleID === 0 ) {
4366                         return true; // avoid gap locking if we know it's not there
4367                 }
4368
4369                 $method = __METHOD__;
4370                 $dbw = wfGetDB( DB_MASTER );
4371                 $conds = $this->pageCond();
4372                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method, $purgeTime ) {
4373                         $dbTimestamp = $dbw->timestamp( $purgeTime ?: time() );
4374
4375                         $dbw->update(
4376                                 'page',
4377                                 [ 'page_touched' => $dbTimestamp ],
4378                                 $conds + [ 'page_touched < ' . $dbw->addQuotes( $dbTimestamp ) ],
4379                                 $method
4380                         );
4381                 } );
4382
4383                 return true;
4384         }
4385
4386         /**
4387          * Update page_touched timestamps and send CDN purge messages for
4388          * pages linking to this title. May be sent to the job queue depending
4389          * on the number of links. Typically called on create and delete.
4390          */
4391         public function touchLinks() {
4392                 DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'pagelinks' ) );
4393                 if ( $this->getNamespace() == NS_CATEGORY ) {
4394                         DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'categorylinks' ) );
4395                 }
4396         }
4397
4398         /**
4399          * Get the last touched timestamp
4400          *
4401          * @param IDatabase $db Optional db
4402          * @return string Last-touched timestamp
4403          */
4404         public function getTouched( $db = null ) {
4405                 if ( $db === null ) {
4406                         $db = wfGetDB( DB_SLAVE );
4407                 }
4408                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4409                 return $touched;
4410         }
4411
4412         /**
4413          * Get the timestamp when this page was updated since the user last saw it.
4414          *
4415          * @param User $user
4416          * @return string|null
4417          */
4418         public function getNotificationTimestamp( $user = null ) {
4419                 global $wgUser;
4420
4421                 // Assume current user if none given
4422                 if ( !$user ) {
4423                         $user = $wgUser;
4424                 }
4425                 // Check cache first
4426                 $uid = $user->getId();
4427                 if ( !$uid ) {
4428                         return false;
4429                 }
4430                 // avoid isset here, as it'll return false for null entries
4431                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4432                         return $this->mNotificationTimestamp[$uid];
4433                 }
4434                 // Don't cache too much!
4435                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4436                         $this->mNotificationTimestamp = [];
4437                 }
4438
4439                 $store = MediaWikiServices::getInstance()->getWatchedItemStore();
4440                 $watchedItem = $store->getWatchedItem( $user, $this );
4441                 if ( $watchedItem ) {
4442                         $this->mNotificationTimestamp[$uid] = $watchedItem->getNotificationTimestamp();
4443                 } else {
4444                         $this->mNotificationTimestamp[$uid] = false;
4445                 }
4446
4447                 return $this->mNotificationTimestamp[$uid];
4448         }
4449
4450         /**
4451          * Generate strings used for xml 'id' names in monobook tabs
4452          *
4453          * @param string $prepend Defaults to 'nstab-'
4454          * @return string XML 'id' name
4455          */
4456         public function getNamespaceKey( $prepend = 'nstab-' ) {
4457                 global $wgContLang;
4458                 // Gets the subject namespace if this title
4459                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4460                 // Checks if canonical namespace name exists for namespace
4461                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4462                         // Uses canonical namespace name
4463                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4464                 } else {
4465                         // Uses text of namespace
4466                         $namespaceKey = $this->getSubjectNsText();
4467                 }
4468                 // Makes namespace key lowercase
4469                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4470                 // Uses main
4471                 if ( $namespaceKey == '' ) {
4472                         $namespaceKey = 'main';
4473                 }
4474                 // Changes file to image for backwards compatibility
4475                 if ( $namespaceKey == 'file' ) {
4476                         $namespaceKey = 'image';
4477                 }
4478                 return $prepend . $namespaceKey;
4479         }
4480
4481         /**
4482          * Get all extant redirects to this Title
4483          *
4484          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4485          * @return Title[] Array of Title redirects to this title
4486          */
4487         public function getRedirectsHere( $ns = null ) {
4488                 $redirs = [];
4489
4490                 $dbr = wfGetDB( DB_SLAVE );
4491                 $where = [
4492                         'rd_namespace' => $this->getNamespace(),
4493                         'rd_title' => $this->getDBkey(),
4494                         'rd_from = page_id'
4495                 ];
4496                 if ( $this->isExternal() ) {
4497                         $where['rd_interwiki'] = $this->getInterwiki();
4498                 } else {
4499                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4500                 }
4501                 if ( !is_null( $ns ) ) {
4502                         $where['page_namespace'] = $ns;
4503                 }
4504
4505                 $res = $dbr->select(
4506                         [ 'redirect', 'page' ],
4507                         [ 'page_namespace', 'page_title' ],
4508                         $where,
4509                         __METHOD__
4510                 );
4511
4512                 foreach ( $res as $row ) {
4513                         $redirs[] = self::newFromRow( $row );
4514                 }
4515                 return $redirs;
4516         }
4517
4518         /**
4519          * Check if this Title is a valid redirect target
4520          *
4521          * @return bool
4522          */
4523         public function isValidRedirectTarget() {
4524                 global $wgInvalidRedirectTargets;
4525
4526                 if ( $this->isSpecialPage() ) {
4527                         // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4528                         if ( $this->isSpecial( 'Userlogout' ) ) {
4529                                 return false;
4530                         }
4531
4532                         foreach ( $wgInvalidRedirectTargets as $target ) {
4533                                 if ( $this->isSpecial( $target ) ) {
4534                                         return false;
4535                                 }
4536                         }
4537                 }
4538
4539                 return true;
4540         }
4541
4542         /**
4543          * Get a backlink cache object
4544          *
4545          * @return BacklinkCache
4546          */
4547         public function getBacklinkCache() {
4548                 return BacklinkCache::get( $this );
4549         }
4550
4551         /**
4552          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4553          *
4554          * @return bool
4555          */
4556         public function canUseNoindex() {
4557                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4558
4559                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4560                         ? $wgContentNamespaces
4561                         : $wgExemptFromUserRobotsControl;
4562
4563                 return !in_array( $this->mNamespace, $bannedNamespaces );
4564
4565         }
4566
4567         /**
4568          * Returns the raw sort key to be used for categories, with the specified
4569          * prefix.  This will be fed to Collation::getSortKey() to get a
4570          * binary sortkey that can be used for actual sorting.
4571          *
4572          * @param string $prefix The prefix to be used, specified using
4573          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4574          *   prefix.
4575          * @return string
4576          */
4577         public function getCategorySortkey( $prefix = '' ) {
4578                 $unprefixed = $this->getText();
4579
4580                 // Anything that uses this hook should only depend
4581                 // on the Title object passed in, and should probably
4582                 // tell the users to run updateCollations.php --force
4583                 // in order to re-sort existing category relations.
4584                 Hooks::run( 'GetDefaultSortkey', [ $this, &$unprefixed ] );
4585                 if ( $prefix !== '' ) {
4586                         # Separate with a line feed, so the unprefixed part is only used as
4587                         # a tiebreaker when two pages have the exact same prefix.
4588                         # In UCA, tab is the only character that can sort above LF
4589                         # so we strip both of them from the original prefix.
4590                         $prefix = strtr( $prefix, "\n\t", '  ' );
4591                         return "$prefix\n$unprefixed";
4592                 }
4593                 return $unprefixed;
4594         }
4595
4596         /**
4597          * Returns the page language code saved in the database, if $wgPageLanguageUseDB is set
4598          * to true in LocalSettings.php, otherwise returns false. If there is no language saved in
4599          * the db, it will return NULL.
4600          *
4601          * @return string|null|bool
4602          */
4603         private function getDbPageLanguageCode() {
4604                 global $wgPageLanguageUseDB;
4605
4606                 // check, if the page language could be saved in the database, and if so and
4607                 // the value is not requested already, lookup the page language using LinkCache
4608                 if ( $wgPageLanguageUseDB && $this->mDbPageLanguage === false ) {
4609                         $linkCache = LinkCache::singleton();
4610                         $linkCache->addLinkObj( $this );
4611                         $this->mDbPageLanguage = $linkCache->getGoodLinkFieldObj( $this, 'lang' );
4612                 }
4613
4614                 return $this->mDbPageLanguage;
4615         }
4616
4617         /**
4618          * Get the language in which the content of this page is written in
4619          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4620          * e.g. $wgLang (such as special pages, which are in the user language).
4621          *
4622          * @since 1.18
4623          * @return Language
4624          */
4625         public function getPageLanguage() {
4626                 global $wgLang, $wgLanguageCode;
4627                 if ( $this->isSpecialPage() ) {
4628                         // special pages are in the user language
4629                         return $wgLang;
4630                 }
4631
4632                 // Checking if DB language is set
4633                 $dbPageLanguage = $this->getDbPageLanguageCode();
4634                 if ( $dbPageLanguage ) {
4635                         return wfGetLangObj( $dbPageLanguage );
4636                 }
4637
4638                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4639                         // Note that this may depend on user settings, so the cache should
4640                         // be only per-request.
4641                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4642                         // content to determine the page language!
4643                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4644                         // tests.
4645                         $contentHandler = ContentHandler::getForTitle( $this );
4646                         $langObj = $contentHandler->getPageLanguage( $this );
4647                         $this->mPageLanguage = [ $langObj->getCode(), $wgLanguageCode ];
4648                 } else {
4649                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4650                 }
4651
4652                 return $langObj;
4653         }
4654
4655         /**
4656          * Get the language in which the content of this page is written when
4657          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4658          * e.g. $wgLang (such as special pages, which are in the user language).
4659          *
4660          * @since 1.20
4661          * @return Language
4662          */
4663         public function getPageViewLanguage() {
4664                 global $wgLang;
4665
4666                 if ( $this->isSpecialPage() ) {
4667                         // If the user chooses a variant, the content is actually
4668                         // in a language whose code is the variant code.
4669                         $variant = $wgLang->getPreferredVariant();
4670                         if ( $wgLang->getCode() !== $variant ) {
4671                                 return Language::factory( $variant );
4672                         }
4673
4674                         return $wgLang;
4675                 }
4676
4677                 // Checking if DB language is set
4678                 $dbPageLanguage = $this->getDbPageLanguageCode();
4679                 if ( $dbPageLanguage ) {
4680                         $pageLang = wfGetLangObj( $dbPageLanguage );
4681                         $variant = $pageLang->getPreferredVariant();
4682                         if ( $pageLang->getCode() !== $variant ) {
4683                                 $pageLang = Language::factory( $variant );
4684                         }
4685
4686                         return $pageLang;
4687                 }
4688
4689                 // @note Can't be cached persistently, depends on user settings.
4690                 // @note ContentHandler::getPageViewLanguage() may need to load the
4691                 //   content to determine the page language!
4692                 $contentHandler = ContentHandler::getForTitle( $this );
4693                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4694                 return $pageLang;
4695         }
4696
4697         /**
4698          * Get a list of rendered edit notices for this page.
4699          *
4700          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4701          * they will already be wrapped in paragraphs.
4702          *
4703          * @since 1.21
4704          * @param int $oldid Revision ID that's being edited
4705          * @return array
4706          */
4707         public function getEditNotices( $oldid = 0 ) {
4708                 $notices = [];
4709
4710                 // Optional notice for the entire namespace
4711                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4712                 $msg = wfMessage( $editnotice_ns );
4713                 if ( $msg->exists() ) {
4714                         $html = $msg->parseAsBlock();
4715                         // Edit notices may have complex logic, but output nothing (T91715)
4716                         if ( trim( $html ) !== '' ) {
4717                                 $notices[$editnotice_ns] = Html::rawElement(
4718                                         'div',
4719                                         [ 'class' => [
4720                                                 'mw-editnotice',
4721                                                 'mw-editnotice-namespace',
4722                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4723                                         ] ],
4724                                         $html
4725                                 );
4726                         }
4727                 }
4728
4729                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4730                         // Optional notice for page itself and any parent page
4731                         $parts = explode( '/', $this->getDBkey() );
4732                         $editnotice_base = $editnotice_ns;
4733                         while ( count( $parts ) > 0 ) {
4734                                 $editnotice_base .= '-' . array_shift( $parts );
4735                                 $msg = wfMessage( $editnotice_base );
4736                                 if ( $msg->exists() ) {
4737                                         $html = $msg->parseAsBlock();
4738                                         if ( trim( $html ) !== '' ) {
4739                                                 $notices[$editnotice_base] = Html::rawElement(
4740                                                         'div',
4741                                                         [ 'class' => [
4742                                                                 'mw-editnotice',
4743                                                                 'mw-editnotice-base',
4744                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4745                                                         ] ],
4746                                                         $html
4747                                                 );
4748                                         }
4749                                 }
4750                         }
4751                 } else {
4752                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4753                         $editnoticeText = $editnotice_ns . '-' . strtr( $this->getDBkey(), '/', '-' );
4754                         $msg = wfMessage( $editnoticeText );
4755                         if ( $msg->exists() ) {
4756                                 $html = $msg->parseAsBlock();
4757                                 if ( trim( $html ) !== '' ) {
4758                                         $notices[$editnoticeText] = Html::rawElement(
4759                                                 'div',
4760                                                 [ 'class' => [
4761                                                         'mw-editnotice',
4762                                                         'mw-editnotice-page',
4763                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4764                                                 ] ],
4765                                                 $html
4766                                         );
4767                                 }
4768                         }
4769                 }
4770
4771                 Hooks::run( 'TitleGetEditNotices', [ $this, $oldid, &$notices ] );
4772                 return $notices;
4773         }
4774
4775         /**
4776          * @return array
4777          */
4778         public function __sleep() {
4779                 return [
4780                         'mNamespace',
4781                         'mDbkeyform',
4782                         'mFragment',
4783                         'mInterwiki',
4784                         'mLocalInterwiki',
4785                         'mUserCaseDBKey',
4786                         'mDefaultNamespace',
4787                 ];
4788         }
4789
4790         public function __wakeup() {
4791                 $this->mArticleID = ( $this->mNamespace >= 0 ) ? -1 : 0;
4792                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
4793                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
4794         }
4795
4796 }