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