includes/Title.php

   1 <?php
   2 /**
   3  * Representation of a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 use Wikimedia\Rdbms\Database;
  26 use Wikimedia\Rdbms\IDatabase;
  27 use MediaWiki\Linker\LinkTarget;
  28 use MediaWiki\Interwiki\InterwikiLookup;
  29 use MediaWiki\MediaWikiServices;
  30
  31 /**
  32  * Represents a title within MediaWiki.
  33  * Optionally may contain an interwiki designation or namespace.
  34  * @note This class can fetch various kinds of data from the database;
  35  *       however, it does so inefficiently.
  36  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  37  *       and does not rely on global state or the database.
  38  */
  39 class Title implements LinkTarget {
  40         /** @var HashBagOStuff */
  41         static private $titleCache = null;
  42
  43         /**
  44          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  45          * commonly used titles. On a batch operation this can become a memory leak
  46          * if not bounded. After hitting this many titles reset the cache.
  47          */
  48         const CACHE_MAX = 1000;
  49
  50         /**
  51          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  52          * to use the master DB
  53          */
  54         const GAID_FOR_UPDATE = 1;
  55
  56         /**
  57          * @name Private member variables
  58          * Please use the accessor functions instead.
  59          * @private
  60          */
  61         // @{
  62
  63         /** @var string Text form (spaces not underscores) of the main part */
  64         public $mTextform = '';
  65
  66         /** @var string URL-encoded form of the main part */
  67         public $mUrlform = '';
  68
  69         /** @var string Main part with underscores */
  70         public $mDbkeyform = '';
  71
  72         /** @var string Database key with the initial letter in the case specified by the user */
  73         protected $mUserCaseDBKey;
  74
  75         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  76         public $mNamespace = NS_MAIN;
  77
  78         /** @var string Interwiki prefix */
  79         public $mInterwiki = '';
  80
  81         /** @var bool Was this Title created from a string with a local interwiki prefix? */
  82         private $mLocalInterwiki = false;
  83
  84         /** @var string Title fragment (i.e. the bit after the #) */
  85         public $mFragment = '';
  86
  87         /** @var int Article ID, fetched from the link cache on demand */
  88         public $mArticleID = -1;
  89
  90         /** @var bool|int ID of most recent revision */
  91         protected $mLatestID = false;
  92
  93         /**
  94          * @var bool|string ID of the page's content model, i.e. one of the
  95          *   CONTENT_MODEL_XXX constants
  96          */
  97         private $mContentModel = false;
  98
  99         /**
 100          * @var bool If a content model was forced via setContentModel()
 101          *   this will be true to avoid having other code paths reset it
 102          */
 103         private $mForcedContentModel = false;
 104
 105         /** @var int Estimated number of revisions; null of not loaded */
 106         private $mEstimateRevisions;
 107
 108         /** @var array Array of groups allowed to edit this article */
 109         public $mRestrictions = [];
 110
 111         /** @var string|bool */
 112         protected $mOldRestrictions = false;
 113
 114         /** @var bool Cascade restrictions on this page to included templates and images? */
 115         public $mCascadeRestriction;
 116
 117         /** Caching the results of getCascadeProtectionSources */
 118         public $mCascadingRestrictions;
 119
 120         /** @var array When do the restrictions on this page expire? */
 121         protected $mRestrictionsExpiry = [];
 122
 123         /** @var bool Are cascading restrictions in effect on this page? */
 124         protected $mHasCascadingRestrictions;
 125
 126         /** @var array Where are the cascading restrictions coming from on this page? */
 127         public $mCascadeSources;
 128
 129         /** @var bool Boolean for initialisation on demand */
 130         public $mRestrictionsLoaded = false;
 131
 132         /** @var string Text form including namespace/interwiki, initialised on demand */
 133         protected $mPrefixedText = null;
 134
 135         /** @var mixed Cached value for getTitleProtection (create protection) */
 136         public $mTitleProtection;
 137
 138         /**
 139          * @var int Namespace index when there is no namespace. Don't change the
 140          *   following default, NS_MAIN is hardcoded in several places. See T2696.
 141          *   Zero except in {{transclusion}} tags.
 142          */
 143         public $mDefaultNamespace = NS_MAIN;
 144
 145         /** @var int The page length, 0 for special pages */
 146         protected $mLength = -1;
 147
 148         /** @var null Is the article at this title a redirect? */
 149         public $mRedirect = null;
 150
 151         /** @var array Associative array of user ID -> timestamp/false */
 152         private $mNotificationTimestamp = [];
 153
 154         /** @var bool Whether a page has any subpages */
 155         private $mHasSubpages;
 156
 157         /** @var bool The (string) language code of the page's language and content code. */
 158         private $mPageLanguage = false;
 159
 160         /** @var string|bool|null The page language code from the database, null if not saved in
 161          * the database or false if not loaded, yet. */
 162         private $mDbPageLanguage = false;
 163
 164         /** @var TitleValue A corresponding TitleValue object */
 165         private $mTitleValue = null;
 166
 167         /** @var bool Would deleting this page be a big deletion? */
 168         private $mIsBigDeletion = null;
 169         // @}
 170
 171         /**
 172          * B/C kludge: provide a TitleParser for use by Title.
 173          * Ideally, Title would have no methods that need this.
 174          * Avoid usage of this singleton by using TitleValue
 175          * and the associated services when possible.
 176          *
 177          * @return TitleFormatter
 178          */
 179         private static function getTitleFormatter() {
 180                 return MediaWikiServices::getInstance()->getTitleFormatter();
 181         }
 182
 183         /**
 184          * B/C kludge: provide an InterwikiLookup for use by Title.
 185          * Ideally, Title would have no methods that need this.
 186          * Avoid usage of this singleton by using TitleValue
 187          * and the associated services when possible.
 188          *
 189          * @return InterwikiLookup
 190          */
 191         private static function getInterwikiLookup() {
 192                 return MediaWikiServices::getInstance()->getInterwikiLookup();
 193         }
 194
 195         /**
 196          * @access protected
 197          */
 198         function __construct() {
 199         }
 200
 201         /**
 202          * Create a new Title from a prefixed DB key
 203          *
 204          * @param string $key The database key, which has underscores
 205          *      instead of spaces, possibly including namespace and
 206          *      interwiki prefixes
 207          * @return Title|null Title, or null on an error
 208          */
 209         public static function newFromDBkey( $key ) {
 210                 $t = new Title();
 211                 $t->mDbkeyform = $key;
 212
 213                 try {
 214                         $t->secureAndSplit();
 215                         return $t;
 216                 } catch ( MalformedTitleException $ex ) {
 217                         return null;
 218                 }
 219         }
 220
 221         /**
 222          * Create a new Title from a TitleValue
 223          *
 224          * @param TitleValue $titleValue Assumed to be safe.
 225          *
 226          * @return Title
 227          */
 228         public static function newFromTitleValue( TitleValue $titleValue ) {
 229                 return self::newFromLinkTarget( $titleValue );
 230         }
 231
 232         /**
 233          * Create a new Title from a LinkTarget
 234          *
 235          * @param LinkTarget $linkTarget Assumed to be safe.
 236          *
 237          * @return Title
 238          */
 239         public static function newFromLinkTarget( LinkTarget $linkTarget ) {
 240                 if ( $linkTarget instanceof Title ) {
 241                         // Special case if it's already a Title object
 242                         return $linkTarget;
 243                 }
 244                 return self::makeTitle(
 245                         $linkTarget->getNamespace(),
 246                         $linkTarget->getText(),
 247                         $linkTarget->getFragment(),
 248                         $linkTarget->getInterwiki()
 249                 );
 250         }
 251
 252         /**
 253          * Create a new Title from text, such as what one would find in a link. De-
 254          * codes any HTML entities in the text.
 255          *
 256          * @param string|int|null $text The link text; spaces, prefixes, and an
 257          *   initial ':' indicating the main namespace are accepted.
 258          * @param int $defaultNamespace The namespace to use if none is specified
 259          *   by a prefix.  If you want to force a specific namespace even if
 260          *   $text might begin with a namespace prefix, use makeTitle() or
 261          *   makeTitleSafe().
 262          * @throws InvalidArgumentException
 263          * @return Title|null Title or null on an error.
 264          */
 265         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 266                 // DWIM: Integers can be passed in here when page titles are used as array keys.
 267                 if ( $text !== null && !is_string( $text ) && !is_int( $text ) ) {
 268                         throw new InvalidArgumentException( '$text must be a string.' );
 269                 }
 270                 if ( $text === null ) {
 271                         return null;
 272                 }
 273
 274                 try {
 275                         return self::newFromTextThrow( strval( $text ), $defaultNamespace );
 276                 } catch ( MalformedTitleException $ex ) {
 277                         return null;
 278                 }
 279         }
 280
 281         /**
 282          * Like Title::newFromText(), but throws MalformedTitleException when the title is invalid,
 283          * rather than returning null.
 284          *
 285          * The exception subclasses encode detailed information about why the title is invalid.
 286          *
 287          * @see Title::newFromText
 288          *
 289          * @since 1.25
 290          * @param string $text Title text to check
 291          * @param int $defaultNamespace
 292          * @throws MalformedTitleException If the title is invalid
 293          * @return Title
 294          */
 295         public static function newFromTextThrow( $text, $defaultNamespace = NS_MAIN ) {
 296                 if ( is_object( $text ) ) {
 297                         throw new MWException( '$text must be a string, given an object' );
 298                 }
 299
 300                 $titleCache = self::getTitleCache();
 301
 302                 // Wiki pages often contain multiple links to the same page.
 303                 // Title normalization and parsing can become expensive on pages with many
 304                 // links, so we can save a little time by caching them.
 305                 // In theory these are value objects and won't get changed...
 306                 if ( $defaultNamespace == NS_MAIN ) {
 307                         $t = $titleCache->get( $text );
 308                         if ( $t ) {
 309                                 return $t;
 310                         }
 311                 }
 312
 313                 // Convert things like &eacute; &#257; or &#x3017; into normalized (T16952) text
 314                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 315
 316                 $t = new Title();
 317                 $t->mDbkeyform = strtr( $filteredText, ' ', '_' );
 318                 $t->mDefaultNamespace = intval( $defaultNamespace );
 319
 320                 $t->secureAndSplit();
 321                 if ( $defaultNamespace == NS_MAIN ) {
 322                         $titleCache->set( $text, $t );
 323                 }
 324                 return $t;
 325         }
 326
 327         /**
 328          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 329          *
 330          * Example of wrong and broken code:
 331          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 332          *
 333          * Example of right code:
 334          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 335          *
 336          * Create a new Title from URL-encoded text. Ensures that
 337          * the given title's length does not exceed the maximum.
 338          *
 339          * @param string $url The title, as might be taken from a URL
 340          * @return Title|null The new object, or null on an error
 341          */
 342         public static function newFromURL( $url ) {
 343                 $t = new Title();
 344
 345                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 346                 # but some URLs used it as a space replacement and they still come
 347                 # from some external search tools.
 348                 if ( strpos( self::legalChars(), '+' ) === false ) {
 349                         $url = strtr( $url, '+', ' ' );
 350                 }
 351
 352                 $t->mDbkeyform = strtr( $url, ' ', '_' );
 353
 354                 try {
 355                         $t->secureAndSplit();
 356                         return $t;
 357                 } catch ( MalformedTitleException $ex ) {
 358                         return null;
 359                 }
 360         }
 361
 362         /**
 363          * @return HashBagOStuff
 364          */
 365         private static function getTitleCache() {
 366                 if ( self::$titleCache == null ) {
 367                         self::$titleCache = new HashBagOStuff( [ 'maxKeys' => self::CACHE_MAX ] );
 368                 }
 369                 return self::$titleCache;
 370         }
 371
 372         /**
 373          * Returns a list of fields that are to be selected for initializing Title
 374          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 375          * whether to include page_content_model.
 376          *
 377          * @return array
 378          */
 379         protected static function getSelectFields() {
 380                 global $wgContentHandlerUseDB, $wgPageLanguageUseDB;
 381
 382                 $fields = [
 383                         'page_namespace', 'page_title', 'page_id',
 384                         'page_len', 'page_is_redirect', 'page_latest',
 385                 ];
 386
 387                 if ( $wgContentHandlerUseDB ) {
 388                         $fields[] = 'page_content_model';
 389                 }
 390
 391                 if ( $wgPageLanguageUseDB ) {
 392                         $fields[] = 'page_lang';
 393                 }
 394
 395                 return $fields;
 396         }
 397
 398         /**
 399          * Create a new Title from an article ID
 400          *
 401          * @param int $id The page_id corresponding to the Title to create
 402          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 403          * @return Title|null The new object, or null on an error
 404          */
 405         public static function newFromID( $id, $flags = 0 ) {
 406                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_REPLICA );
 407                 $row = $db->selectRow(
 408                         'page',
 409                         self::getSelectFields(),
 410                         [ 'page_id' => $id ],
 411                         __METHOD__
 412                 );
 413                 if ( $row !== false ) {
 414                         $title = self::newFromRow( $row );
 415                 } else {
 416                         $title = null;
 417                 }
 418                 return $title;
 419         }
 420
 421         /**
 422          * Make an array of titles from an array of IDs
 423          *
 424          * @param int[] $ids Array of IDs
 425          * @return Title[] Array of Titles
 426          */
 427         public static function newFromIDs( $ids ) {
 428                 if ( !count( $ids ) ) {
 429                         return [];
 430                 }
 431                 $dbr = wfGetDB( DB_REPLICA );
 432
 433                 $res = $dbr->select(
 434                         'page',
 435                         self::getSelectFields(),
 436                         [ 'page_id' => $ids ],
 437                         __METHOD__
 438                 );
 439
 440                 $titles = [];
 441                 foreach ( $res as $row ) {
 442                         $titles[] = self::newFromRow( $row );
 443                 }
 444                 return $titles;
 445         }
 446
 447         /**
 448          * Make a Title object from a DB row
 449          *
 450          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 451          * @return Title Corresponding Title
 452          */
 453         public static function newFromRow( $row ) {
 454                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 455                 $t->loadFromRow( $row );
 456                 return $t;
 457         }
 458
 459         /**
 460          * Load Title object fields from a DB row.
 461          * If false is given, the title will be treated as non-existing.
 462          *
 463          * @param stdClass|bool $row Database row
 464          */
 465         public function loadFromRow( $row ) {
 466                 if ( $row ) { // page found
 467                         if ( isset( $row->page_id ) ) {
 468                                 $this->mArticleID = (int)$row->page_id;
 469                         }
 470                         if ( isset( $row->page_len ) ) {
 471                                 $this->mLength = (int)$row->page_len;
 472                         }
 473                         if ( isset( $row->page_is_redirect ) ) {
 474                                 $this->mRedirect = (bool)$row->page_is_redirect;
 475                         }
 476                         if ( isset( $row->page_latest ) ) {
 477                                 $this->mLatestID = (int)$row->page_latest;
 478                         }
 479                         if ( !$this->mForcedContentModel && isset( $row->page_content_model ) ) {
 480                                 $this->mContentModel = strval( $row->page_content_model );
 481                         } elseif ( !$this->mForcedContentModel ) {
 482                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 483                         }
 484                         if ( isset( $row->page_lang ) ) {
 485                                 $this->mDbPageLanguage = (string)$row->page_lang;
 486                         }
 487                         if ( isset( $row->page_restrictions ) ) {
 488                                 $this->mOldRestrictions = $row->page_restrictions;
 489                         }
 490                 } else { // page not found
 491                         $this->mArticleID = 0;
 492                         $this->mLength = 0;
 493                         $this->mRedirect = false;
 494                         $this->mLatestID = 0;
 495                         if ( !$this->mForcedContentModel ) {
 496                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 497                         }
 498                 }
 499         }
 500
 501         /**
 502          * Create a new Title from a namespace index and a DB key.
 503          * It's assumed that $ns and $title are *valid*, for instance when
 504          * they came directly from the database or a special page name.
 505          * For convenience, spaces are converted to underscores so that
 506          * eg user_text fields can be used directly.
 507          *
 508          * @param int $ns The namespace of the article
 509          * @param string $title The unprefixed database key form
 510          * @param string $fragment The link fragment (after the "#")
 511          * @param string $interwiki The interwiki prefix
 512          * @return Title The new object
 513          */
 514         public static function makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 515                 $t = new Title();
 516                 $t->mInterwiki = $interwiki;
 517                 $t->mFragment = $fragment;
 518                 $t->mNamespace = $ns = intval( $ns );
 519                 $t->mDbkeyform = strtr( $title, ' ', '_' );
 520                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 521                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 522                 $t->mTextform = strtr( $title, '_', ' ' );
 523                 $t->mContentModel = false; # initialized lazily in getContentModel()
 524                 return $t;
 525         }
 526
 527         /**
 528          * Create a new Title from a namespace index and a DB key.
 529          * The parameters will be checked for validity, which is a bit slower
 530          * than makeTitle() but safer for user-provided data.
 531          *
 532          * @param int $ns The namespace of the article
 533          * @param string $title Database key form
 534          * @param string $fragment The link fragment (after the "#")
 535          * @param string $interwiki Interwiki prefix
 536          * @return Title|null The new object, or null on an error
 537          */
 538         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 539                 if ( !MWNamespace::exists( $ns ) ) {
 540                         return null;
 541                 }
 542
 543                 $t = new Title();
 544                 $t->mDbkeyform = self::makeName( $ns, $title, $fragment, $interwiki, true );
 545
 546                 try {
 547                         $t->secureAndSplit();
 548                         return $t;
 549                 } catch ( MalformedTitleException $ex ) {
 550                         return null;
 551                 }
 552         }
 553
 554         /**
 555          * Create a new Title for the Main Page
 556          *
 557          * @return Title The new object
 558          */
 559         public static function newMainPage() {
 560                 $title = self::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 561                 // Don't give fatal errors if the message is broken
 562                 if ( !$title ) {
 563                         $title = self::newFromText( 'Main Page' );
 564                 }
 565                 return $title;
 566         }
 567
 568         /**
 569          * Get the prefixed DB key associated with an ID
 570          *
 571          * @param int $id The page_id of the article
 572          * @return Title|null An object representing the article, or null if no such article was found
 573          */
 574         public static function nameOf( $id ) {
 575                 $dbr = wfGetDB( DB_REPLICA );
 576
 577                 $s = $dbr->selectRow(
 578                         'page',
 579                         [ 'page_namespace', 'page_title' ],
 580                         [ 'page_id' => $id ],
 581                         __METHOD__
 582                 );
 583                 if ( $s === false ) {
 584                         return null;
 585                 }
 586
 587                 $n = self::makeName( $s->page_namespace, $s->page_title );
 588                 return $n;
 589         }
 590
 591         /**
 592          * Get a regex character class describing the legal characters in a link
 593          *
 594          * @return string The list of characters, not delimited
 595          */
 596         public static function legalChars() {
 597                 global $wgLegalTitleChars;
 598                 return $wgLegalTitleChars;
 599         }
 600
 601         /**
 602          * Returns a simple regex that will match on characters and sequences invalid in titles.
 603          * Note that this doesn't pick up many things that could be wrong with titles, but that
 604          * replacing this regex with something valid will make many titles valid.
 605          *
 606          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 607          *
 608          * @return string Regex string
 609          */
 610         static function getTitleInvalidRegex() {
 611                 wfDeprecated( __METHOD__, '1.25' );
 612                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 613         }
 614
 615         /**
 616          * Utility method for converting a character sequence from bytes to Unicode.
 617          *
 618          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 619          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 620          *
 621          * @param string $byteClass
 622          * @return string
 623          */
 624         public static function convertByteClassToUnicodeClass( $byteClass ) {
 625                 $length = strlen( $byteClass );
 626                 // Input token queue
 627                 $x0 = $x1 = $x2 = '';
 628                 // Decoded queue
 629                 $d0 = $d1 = $d2 = '';
 630                 // Decoded integer codepoints
 631                 $ord0 = $ord1 = $ord2 = 0;
 632                 // Re-encoded queue
 633                 $r0 = $r1 = $r2 = '';
 634                 // Output
 635                 $out = '';
 636                 // Flags
 637                 $allowUnicode = false;
 638                 for ( $pos = 0; $pos < $length; $pos++ ) {
 639                         // Shift the queues down
 640                         $x2 = $x1;
 641                         $x1 = $x0;
 642                         $d2 = $d1;
 643                         $d1 = $d0;
 644                         $ord2 = $ord1;
 645                         $ord1 = $ord0;
 646                         $r2 = $r1;
 647                         $r1 = $r0;
 648                         // Load the current input token and decoded values
 649                         $inChar = $byteClass[$pos];
 650                         if ( $inChar == '\\' ) {
 651                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 652                                         $x0 = $inChar . $m[0];
 653                                         $d0 = chr( hexdec( $m[1] ) );
 654                                         $pos += strlen( $m[0] );
 655                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 656                                         $x0 = $inChar . $m[0];
 657                                         $d0 = chr( octdec( $m[0] ) );
 658                                         $pos += strlen( $m[0] );
 659                                 } elseif ( $pos + 1 >= $length ) {
 660                                         $x0 = $d0 = '\\';
 661                                 } else {
 662                                         $d0 = $byteClass[$pos + 1];
 663                                         $x0 = $inChar . $d0;
 664                                         $pos += 1;
 665                                 }
 666                         } else {
 667                                 $x0 = $d0 = $inChar;
 668                         }
 669                         $ord0 = ord( $d0 );
 670                         // Load the current re-encoded value
 671                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 672                                 $r0 = sprintf( '\x%02x', $ord0 );
 673                         } elseif ( $ord0 >= 0x80 ) {
 674                                 // Allow unicode if a single high-bit character appears
 675                                 $r0 = sprintf( '\x%02x', $ord0 );
 676                                 $allowUnicode = true;
 677                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 678                                 $r0 = '\\' . $d0;
 679                         } else {
 680                                 $r0 = $d0;
 681                         }
 682                         // Do the output
 683                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 684                                 // Range
 685                                 if ( $ord2 > $ord0 ) {
 686                                         // Empty range
 687                                 } elseif ( $ord0 >= 0x80 ) {
 688                                         // Unicode range
 689                                         $allowUnicode = true;
 690                                         if ( $ord2 < 0x80 ) {
 691                                                 // Keep the non-unicode section of the range
 692                                                 $out .= "$r2-\\x7F";
 693                                         }
 694                                 } else {
 695                                         // Normal range
 696                                         $out .= "$r2-$r0";
 697                                 }
 698                                 // Reset state to the initial value
 699                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 700                         } elseif ( $ord2 < 0x80 ) {
 701                                 // ASCII character
 702                                 $out .= $r2;
 703                         }
 704                 }
 705                 if ( $ord1 < 0x80 ) {
 706                         $out .= $r1;
 707                 }
 708                 if ( $ord0 < 0x80 ) {
 709                         $out .= $r0;
 710                 }
 711                 if ( $allowUnicode ) {
 712                         $out .= '\u0080-\uFFFF';
 713                 }
 714                 return $out;
 715         }
 716
 717         /**
 718          * Make a prefixed DB key from a DB key and a namespace index
 719          *
 720          * @param int $ns Numerical representation of the namespace
 721          * @param string $title The DB key form the title
 722          * @param string $fragment The link fragment (after the "#")
 723          * @param string $interwiki The interwiki prefix
 724          * @param bool $canonicalNamespace If true, use the canonical name for
 725          *   $ns instead of the localized version.
 726          * @return string The prefixed form of the title
 727          */
 728         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 729                 $canonicalNamespace = false
 730         ) {
 731                 global $wgContLang;
 732
 733                 if ( $canonicalNamespace ) {
 734                         $namespace = MWNamespace::getCanonicalName( $ns );
 735                 } else {
 736                         $namespace = $wgContLang->getNsText( $ns );
 737                 }
 738                 $name = $namespace == '' ? $title : "$namespace:$title";
 739                 if ( strval( $interwiki ) != '' ) {
 740                         $name = "$interwiki:$name";
 741                 }
 742                 if ( strval( $fragment ) != '' ) {
 743                         $name .= '#' . $fragment;
 744                 }
 745                 return $name;
 746         }
 747
 748         /**
 749          * Escape a text fragment, say from a link, for a URL
 750          *
 751          * @deprecated since 1.30, use Sanitizer::escapeIdForLink() or escapeIdForExternalInterwiki()
 752          *
 753          * @param string $fragment Containing a URL or link fragment (after the "#")
 754          * @return string Escaped string
 755          */
 756         static function escapeFragmentForURL( $fragment ) {
 757                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 758                 # fragments appear not to work in IE (at least up to 7) or in at least
 759                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 760                 # to care if they aren't encoded.
 761                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 762         }
 763
 764         /**
 765          * Callback for usort() to do title sorts by (namespace, title)
 766          *
 767          * @param LinkTarget $a
 768          * @param LinkTarget $b
 769          *
 770          * @return int Result of string comparison, or namespace comparison
 771          */
 772         public static function compare( LinkTarget $a, LinkTarget $b ) {
 773                 if ( $a->getNamespace() == $b->getNamespace() ) {
 774                         return strcmp( $a->getText(), $b->getText() );
 775                 } else {
 776                         return $a->getNamespace() - $b->getNamespace();
 777                 }
 778         }
 779
 780         /**
 781          * Determine whether the object refers to a page within
 782          * this project (either this wiki or a wiki with a local
 783          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 784          *
 785          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 786          */
 787         public function isLocal() {
 788                 if ( $this->isExternal() ) {
 789                         $iw = self::getInterwikiLookup()->fetch( $this->mInterwiki );
 790                         if ( $iw ) {
 791                                 return $iw->isLocal();
 792                         }
 793                 }
 794                 return true;
 795         }
 796
 797         /**
 798          * Is this Title interwiki?
 799          *
 800          * @return bool
 801          */
 802         public function isExternal() {
 803                 return $this->mInterwiki !== '';
 804         }
 805
 806         /**
 807          * Get the interwiki prefix
 808          *
 809          * Use Title::isExternal to check if a interwiki is set
 810          *
 811          * @return string Interwiki prefix
 812          */
 813         public function getInterwiki() {
 814                 return $this->mInterwiki;
 815         }
 816
 817         /**
 818          * Was this a local interwiki link?
 819          *
 820          * @return bool
 821          */
 822         public function wasLocalInterwiki() {
 823                 return $this->mLocalInterwiki;
 824         }
 825
 826         /**
 827          * Determine whether the object refers to a page within
 828          * this project and is transcludable.
 829          *
 830          * @return bool True if this is transcludable
 831          */
 832         public function isTrans() {
 833                 if ( !$this->isExternal() ) {
 834                         return false;
 835                 }
 836
 837                 return self::getInterwikiLookup()->fetch( $this->mInterwiki )->isTranscludable();
 838         }
 839
 840         /**
 841          * Returns the DB name of the distant wiki which owns the object.
 842          *
 843          * @return string|false The DB name
 844          */
 845         public function getTransWikiID() {
 846                 if ( !$this->isExternal() ) {
 847                         return false;
 848                 }
 849
 850                 return self::getInterwikiLookup()->fetch( $this->mInterwiki )->getWikiID();
 851         }
 852
 853         /**
 854          * Get a TitleValue object representing this Title.
 855          *
 856          * @note Not all valid Titles have a corresponding valid TitleValue
 857          * (e.g. TitleValues cannot represent page-local links that have a
 858          * fragment but no title text).
 859          *
 860          * @return TitleValue|null
 861          */
 862         public function getTitleValue() {
 863                 if ( $this->mTitleValue === null ) {
 864                         try {
 865                                 $this->mTitleValue = new TitleValue(
 866                                         $this->getNamespace(),
 867                                         $this->getDBkey(),
 868                                         $this->getFragment(),
 869                                         $this->getInterwiki()
 870                                 );
 871                         } catch ( InvalidArgumentException $ex ) {
 872                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 873                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 874                         }
 875                 }
 876
 877                 return $this->mTitleValue;
 878         }
 879
 880         /**
 881          * Get the text form (spaces not underscores) of the main part
 882          *
 883          * @return string Main part of the title
 884          */
 885         public function getText() {
 886                 return $this->mTextform;
 887         }
 888
 889         /**
 890          * Get the URL-encoded form of the main part
 891          *
 892          * @return string Main part of the title, URL-encoded
 893          */
 894         public function getPartialURL() {
 895                 return $this->mUrlform;
 896         }
 897
 898         /**
 899          * Get the main part with underscores
 900          *
 901          * @return string Main part of the title, with underscores
 902          */
 903         public function getDBkey() {
 904                 return $this->mDbkeyform;
 905         }
 906
 907         /**
 908          * Get the DB key with the initial letter case as specified by the user
 909          *
 910          * @return string DB key
 911          */
 912         function getUserCaseDBKey() {
 913                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 914                         return $this->mUserCaseDBKey;
 915                 } else {
 916                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 917                         return $this->mDbkeyform;
 918                 }
 919         }
 920
 921         /**
 922          * Get the namespace index, i.e. one of the NS_xxxx constants.
 923          *
 924          * @return int Namespace index
 925          */
 926         public function getNamespace() {
 927                 return $this->mNamespace;
 928         }
 929
 930         /**
 931          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 932          *
 933          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 934          * @return string Content model id
 935          */
 936         public function getContentModel( $flags = 0 ) {
 937                 if ( !$this->mForcedContentModel
 938                         && ( !$this->mContentModel || $flags === self::GAID_FOR_UPDATE )
 939                         && $this->getArticleID( $flags )
 940                 ) {
 941                         $linkCache = LinkCache::singleton();
 942                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 943                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 944                 }
 945
 946                 if ( !$this->mContentModel ) {
 947                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 948                 }
 949
 950                 return $this->mContentModel;
 951         }
 952
 953         /**
 954          * Convenience method for checking a title's content model name
 955          *
 956          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 957          * @return bool True if $this->getContentModel() == $id
 958          */
 959         public function hasContentModel( $id ) {
 960                 return $this->getContentModel() == $id;
 961         }
 962
 963         /**
 964          * Set a proposed content model for the page for permissions
 965          * checking. This does not actually change the content model
 966          * of a title!
 967          *
 968          * Additionally, you should make sure you've checked
 969          * ContentHandler::canBeUsedOn() first.
 970          *
 971          * @since 1.28
 972          * @param string $model CONTENT_MODEL_XXX constant
 973          */
 974         public function setContentModel( $model ) {
 975                 $this->mContentModel = $model;
 976                 $this->mForcedContentModel = true;
 977         }
 978
 979         /**
 980          * Get the namespace text
 981          *
 982          * @return string|false Namespace text
 983          */
 984         public function getNsText() {
 985                 if ( $this->isExternal() ) {
 986                         // This probably shouldn't even happen,
 987                         // but for interwiki transclusion it sometimes does.
 988                         // Use the canonical namespaces if possible to try to
 989                         // resolve a foreign namespace.
 990                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 991                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 992                         }
 993                 }
 994
 995                 try {
 996                         $formatter = self::getTitleFormatter();
 997                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 998                 } catch ( InvalidArgumentException $ex ) {
 999                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
1000                         return false;
1001                 }
1002         }
1003
1004         /**
1005          * Get the namespace text of the subject (rather than talk) page
1006          *
1007          * @return string Namespace text
1008          */
1009         public function getSubjectNsText() {
1010                 global $wgContLang;
1011                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1012         }
1013
1014         /**
1015          * Get the namespace text of the talk page
1016          *
1017          * @return string Namespace text
1018          */
1019         public function getTalkNsText() {
1020                 global $wgContLang;
1021                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1022         }
1023
1024         /**
1025          * Can this title have a corresponding talk page?
1026          *
1027          * @deprecated since 1.30, use canHaveTalkPage() instead.
1028          *
1029          * @return bool True if this title either is a talk page or can have a talk page associated.
1030          */
1031         public function canTalk() {
1032                 return $this->canHaveTalkPage();
1033         }
1034
1035         /**
1036          * Can this title have a corresponding talk page?
1037          *
1038          * @see MWNamespace::hasTalkNamespace
1039          * @since 1.30
1040          *
1041          * @return bool True if this title either is a talk page or can have a talk page associated.
1042          */
1043         public function canHaveTalkPage() {
1044                 return MWNamespace::hasTalkNamespace( $this->mNamespace );
1045         }
1046
1047         /**
1048          * Is this in a namespace that allows actual pages?
1049          *
1050          * @return bool
1051          */
1052         public function canExist() {
1053                 return $this->mNamespace >= NS_MAIN;
1054         }
1055
1056         /**
1057          * Can this title be added to a user's watchlist?
1058          *
1059          * @return bool
1060          */
1061         public function isWatchable() {
1062                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1063         }
1064
1065         /**
1066          * Returns true if this is a special page.
1067          *
1068          * @return bool
1069          */
1070         public function isSpecialPage() {
1071                 return $this->getNamespace() == NS_SPECIAL;
1072         }
1073
1074         /**
1075          * Returns true if this title resolves to the named special page
1076          *
1077          * @param string $name The special page name
1078          * @return bool
1079          */
1080         public function isSpecial( $name ) {
1081                 if ( $this->isSpecialPage() ) {
1082                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1083                         if ( $name == $thisName ) {
1084                                 return true;
1085                         }
1086                 }
1087                 return false;
1088         }
1089
1090         /**
1091          * If the Title refers to a special page alias which is not the local default, resolve
1092          * the alias, and localise the name as necessary.  Otherwise, return $this
1093          *
1094          * @return Title
1095          */
1096         public function fixSpecialName() {
1097                 if ( $this->isSpecialPage() ) {
1098                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1099                         if ( $canonicalName ) {
1100                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1101                                 if ( $localName != $this->mDbkeyform ) {
1102                                         return self::makeTitle( NS_SPECIAL, $localName );
1103                                 }
1104                         }
1105                 }
1106                 return $this;
1107         }
1108
1109         /**
1110          * Returns true if the title is inside the specified namespace.
1111          *
1112          * Please make use of this instead of comparing to getNamespace()
1113          * This function is much more resistant to changes we may make
1114          * to namespaces than code that makes direct comparisons.
1115          * @param int $ns The namespace
1116          * @return bool
1117          * @since 1.19
1118          */
1119         public function inNamespace( $ns ) {
1120                 return MWNamespace::equals( $this->getNamespace(), $ns );
1121         }
1122
1123         /**
1124          * Returns true if the title is inside one of the specified namespaces.
1125          *
1126          * @param int|int[] $namespaces,... The namespaces to check for
1127          * @return bool
1128          * @since 1.19
1129          */
1130         public function inNamespaces( /* ... */ ) {
1131                 $namespaces = func_get_args();
1132                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1133                         $namespaces = $namespaces[0];
1134                 }
1135
1136                 foreach ( $namespaces as $ns ) {
1137                         if ( $this->inNamespace( $ns ) ) {
1138                                 return true;
1139                         }
1140                 }
1141
1142                 return false;
1143         }
1144
1145         /**
1146          * Returns true if the title has the same subject namespace as the
1147          * namespace specified.
1148          * For example this method will take NS_USER and return true if namespace
1149          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1150          * as their subject namespace.
1151          *
1152          * This is MUCH simpler than individually testing for equivalence
1153          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1154          * @since 1.19
1155          * @param int $ns
1156          * @return bool
1157          */
1158         public function hasSubjectNamespace( $ns ) {
1159                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1160         }
1161
1162         /**
1163          * Is this Title in a namespace which contains content?
1164          * In other words, is this a content page, for the purposes of calculating
1165          * statistics, etc?
1166          *
1167          * @return bool
1168          */
1169         public function isContentPage() {
1170                 return MWNamespace::isContent( $this->getNamespace() );
1171         }
1172
1173         /**
1174          * Would anybody with sufficient privileges be able to move this page?
1175          * Some pages just aren't movable.
1176          *
1177          * @return bool
1178          */
1179         public function isMovable() {
1180                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1181                         // Interwiki title or immovable namespace. Hooks don't get to override here
1182                         return false;
1183                 }
1184
1185                 $result = true;
1186                 Hooks::run( 'TitleIsMovable', [ $this, &$result ] );
1187                 return $result;
1188         }
1189
1190         /**
1191          * Is this the mainpage?
1192          * @note Title::newFromText seems to be sufficiently optimized by the title
1193          * cache that we don't need to over-optimize by doing direct comparisons and
1194          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1195          * ends up reporting something differently than $title->isMainPage();
1196          *
1197          * @since 1.18
1198          * @return bool
1199          */
1200         public function isMainPage() {
1201                 return $this->equals( self::newMainPage() );
1202         }
1203
1204         /**
1205          * Is this a subpage?
1206          *
1207          * @return bool
1208          */
1209         public function isSubpage() {
1210                 return MWNamespace::hasSubpages( $this->mNamespace )
1211                         ? strpos( $this->getText(), '/' ) !== false
1212                         : false;
1213         }
1214
1215         /**
1216          * Is this a conversion table for the LanguageConverter?
1217          *
1218          * @return bool
1219          */
1220         public function isConversionTable() {
1221                 // @todo ConversionTable should become a separate content model.
1222
1223                 return $this->getNamespace() == NS_MEDIAWIKI &&
1224                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1225         }
1226
1227         /**
1228          * Does that page contain wikitext, or it is JS, CSS or whatever?
1229          *
1230          * @return bool
1231          */
1232         public function isWikitextPage() {
1233                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1234         }
1235
1236         /**
1237          * Could this page contain custom CSS or JavaScript for the global UI.
1238          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1239          * or CONTENT_MODEL_JAVASCRIPT.
1240          *
1241          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1242          * for that!
1243          *
1244          * Note that this method should not return true for pages that contain and
1245          * show "inactive" CSS or JS.
1246          *
1247          * @return bool
1248          * @todo FIXME: Rename to isSiteConfigPage() and remove deprecated hook
1249          */
1250         public function isCssOrJsPage() {
1251                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1252                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1253                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1254
1255                 return $isCssOrJsPage;
1256         }
1257
1258         /**
1259          * Is this a .css or .js subpage of a user page?
1260          * @return bool
1261          * @todo FIXME: Rename to isUserConfigPage()
1262          */
1263         public function isCssJsSubpage() {
1264                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1265                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1266                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1267         }
1268
1269         /**
1270          * Trim down a .css or .js subpage title to get the corresponding skin name
1271          *
1272          * @return string Containing skin name from .css or .js subpage title
1273          */
1274         public function getSkinFromCssJsSubpage() {
1275                 $subpage = explode( '/', $this->mTextform );
1276                 $subpage = $subpage[count( $subpage ) - 1];
1277                 $lastdot = strrpos( $subpage, '.' );
1278                 if ( $lastdot === false ) {
1279                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1280                 }
1281                 return substr( $subpage, 0, $lastdot );
1282         }
1283
1284         /**
1285          * Is this a .css subpage of a user page?
1286          *
1287          * @return bool
1288          */
1289         public function isCssSubpage() {
1290                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1291                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1292         }
1293
1294         /**
1295          * Is this a .js subpage of a user page?
1296          *
1297          * @return bool
1298          */
1299         public function isJsSubpage() {
1300                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1301                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1302         }
1303
1304         /**
1305          * Is this a talk page of some sort?
1306          *
1307          * @return bool
1308          */
1309         public function isTalkPage() {
1310                 return MWNamespace::isTalk( $this->getNamespace() );
1311         }
1312
1313         /**
1314          * Get a Title object associated with the talk page of this article
1315          *
1316          * @return Title The object for the talk page
1317          */
1318         public function getTalkPage() {
1319                 return self::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1320         }
1321
1322         /**
1323          * Get a Title object associated with the talk page of this article,
1324          * if such a talk page can exist.
1325          *
1326          * @since 1.30
1327          *
1328          * @return Title|null The object for the talk page,
1329          *         or null if no associated talk page can exist, according to canHaveTalkPage().
1330          */
1331         public function getTalkPageIfDefined() {
1332                 if ( !$this->canHaveTalkPage() ) {
1333                         return null;
1334                 }
1335
1336                 return $this->getTalkPage();
1337         }
1338
1339         /**
1340          * Get a title object associated with the subject page of this
1341          * talk page
1342          *
1343          * @return Title The object for the subject page
1344          */
1345         public function getSubjectPage() {
1346                 // Is this the same title?
1347                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1348                 if ( $this->getNamespace() == $subjectNS ) {
1349                         return $this;
1350                 }
1351                 return self::makeTitle( $subjectNS, $this->getDBkey() );
1352         }
1353
1354         /**
1355          * Get the other title for this page, if this is a subject page
1356          * get the talk page, if it is a subject page get the talk page
1357          *
1358          * @since 1.25
1359          * @throws MWException
1360          * @return Title
1361          */
1362         public function getOtherPage() {
1363                 if ( $this->isSpecialPage() ) {
1364                         throw new MWException( 'Special pages cannot have other pages' );
1365                 }
1366                 if ( $this->isTalkPage() ) {
1367                         return $this->getSubjectPage();
1368                 } else {
1369                         return $this->getTalkPage();
1370                 }
1371         }
1372
1373         /**
1374          * Get the default namespace index, for when there is no namespace
1375          *
1376          * @return int Default namespace index
1377          */
1378         public function getDefaultNamespace() {
1379                 return $this->mDefaultNamespace;
1380         }
1381
1382         /**
1383          * Get the Title fragment (i.e.\ the bit after the #) in text form
1384          *
1385          * Use Title::hasFragment to check for a fragment
1386          *
1387          * @return string Title fragment
1388          */
1389         public function getFragment() {
1390                 return $this->mFragment;
1391         }
1392
1393         /**
1394          * Check if a Title fragment is set
1395          *
1396          * @return bool
1397          * @since 1.23
1398          */
1399         public function hasFragment() {
1400                 return $this->mFragment !== '';
1401         }
1402
1403         /**
1404          * Get the fragment in URL form, including the "#" character if there is one
1405          *
1406          * @return string Fragment in URL form
1407          */
1408         public function getFragmentForURL() {
1409                 if ( !$this->hasFragment() ) {
1410                         return '';
1411                 } elseif ( $this->isExternal() && !$this->getTransWikiID() ) {
1412                         return '#' . Sanitizer::escapeIdForExternalInterwiki( $this->getFragment() );
1413                 }
1414                 return '#' . Sanitizer::escapeIdForLink( $this->getFragment() );
1415         }
1416
1417         /**
1418          * Set the fragment for this title. Removes the first character from the
1419          * specified fragment before setting, so it assumes you're passing it with
1420          * an initial "#".
1421          *
1422          * Deprecated for public use, use Title::makeTitle() with fragment parameter,
1423          * or Title::createFragmentTarget().
1424          * Still in active use privately.
1425          *
1426          * @private
1427          * @param string $fragment Text
1428          */
1429         public function setFragment( $fragment ) {
1430                 $this->mFragment = strtr( substr( $fragment, 1 ), '_', ' ' );
1431         }
1432
1433         /**
1434          * Creates a new Title for a different fragment of the same page.
1435          *
1436          * @since 1.27
1437          * @param string $fragment
1438          * @return Title
1439          */
1440         public function createFragmentTarget( $fragment ) {
1441                 return self::makeTitle(
1442                         $this->getNamespace(),
1443                         $this->getText(),
1444                         $fragment,
1445                         $this->getInterwiki()
1446                 );
1447         }
1448
1449         /**
1450          * Prefix some arbitrary text with the namespace or interwiki prefix
1451          * of this object
1452          *
1453          * @param string $name The text
1454          * @return string The prefixed text
1455          */
1456         private function prefix( $name ) {
1457                 global $wgContLang;
1458
1459                 $p = '';
1460                 if ( $this->isExternal() ) {
1461                         $p = $this->mInterwiki . ':';
1462                 }
1463
1464                 if ( 0 != $this->mNamespace ) {
1465                         $nsText = $this->getNsText();
1466
1467                         if ( $nsText === false ) {
1468                                 // See T165149. Awkward, but better than erroneously linking to the main namespace.
1469                                 $nsText = $wgContLang->getNsText( NS_SPECIAL ) . ":Badtitle/NS{$this->mNamespace}";
1470                         }
1471
1472                         $p .= $nsText . ':';
1473                 }
1474                 return $p . $name;
1475         }
1476
1477         /**
1478          * Get the prefixed database key form
1479          *
1480          * @return string The prefixed title, with underscores and
1481          *  any interwiki and namespace prefixes
1482          */
1483         public function getPrefixedDBkey() {
1484                 $s = $this->prefix( $this->mDbkeyform );
1485                 $s = strtr( $s, ' ', '_' );
1486                 return $s;
1487         }
1488
1489         /**
1490          * Get the prefixed title with spaces.
1491          * This is the form usually used for display
1492          *
1493          * @return string The prefixed title, with spaces
1494          */
1495         public function getPrefixedText() {
1496                 if ( $this->mPrefixedText === null ) {
1497                         $s = $this->prefix( $this->mTextform );
1498                         $s = strtr( $s, '_', ' ' );
1499                         $this->mPrefixedText = $s;
1500                 }
1501                 return $this->mPrefixedText;
1502         }
1503
1504         /**
1505          * Return a string representation of this title
1506          *
1507          * @return string Representation of this title
1508          */
1509         public function __toString() {
1510                 return $this->getPrefixedText();
1511         }
1512
1513         /**
1514          * Get the prefixed title with spaces, plus any fragment
1515          * (part beginning with '#')
1516          *
1517          * @return string The prefixed title, with spaces and the fragment, including '#'
1518          */
1519         public function getFullText() {
1520                 $text = $this->getPrefixedText();
1521                 if ( $this->hasFragment() ) {
1522                         $text .= '#' . $this->getFragment();
1523                 }
1524                 return $text;
1525         }
1526
1527         /**
1528          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1529          *
1530          * @par Example:
1531          * @code
1532          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1533          * # returns: 'Foo'
1534          * @endcode
1535          *
1536          * @return string Root name
1537          * @since 1.20
1538          */
1539         public function getRootText() {
1540                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1541                         return $this->getText();
1542                 }
1543
1544                 return strtok( $this->getText(), '/' );
1545         }
1546
1547         /**
1548          * Get the root page name title, i.e. the leftmost part before any slashes
1549          *
1550          * @par Example:
1551          * @code
1552          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1553          * # returns: Title{User:Foo}
1554          * @endcode
1555          *
1556          * @return Title Root title
1557          * @since 1.20
1558          */
1559         public function getRootTitle() {
1560                 return self::makeTitle( $this->getNamespace(), $this->getRootText() );
1561         }
1562
1563         /**
1564          * Get the base page name without a namespace, i.e. the part before the subpage name
1565          *
1566          * @par Example:
1567          * @code
1568          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1569          * # returns: 'Foo/Bar'
1570          * @endcode
1571          *
1572          * @return string Base name
1573          */
1574         public function getBaseText() {
1575                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1576                         return $this->getText();
1577                 }
1578
1579                 $parts = explode( '/', $this->getText() );
1580                 # Don't discard the real title if there's no subpage involved
1581                 if ( count( $parts ) > 1 ) {
1582                         unset( $parts[count( $parts ) - 1] );
1583                 }
1584                 return implode( '/', $parts );
1585         }
1586
1587         /**
1588          * Get the base page name title, i.e. the part before the subpage name
1589          *
1590          * @par Example:
1591          * @code
1592          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1593          * # returns: Title{User:Foo/Bar}
1594          * @endcode
1595          *
1596          * @return Title Base title
1597          * @since 1.20
1598          */
1599         public function getBaseTitle() {
1600                 return self::makeTitle( $this->getNamespace(), $this->getBaseText() );
1601         }
1602
1603         /**
1604          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1605          *
1606          * @par Example:
1607          * @code
1608          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1609          * # returns: "Baz"
1610          * @endcode
1611          *
1612          * @return string Subpage name
1613          */
1614         public function getSubpageText() {
1615                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1616                         return $this->mTextform;
1617                 }
1618                 $parts = explode( '/', $this->mTextform );
1619                 return $parts[count( $parts ) - 1];
1620         }
1621
1622         /**
1623          * Get the title for a subpage of the current page
1624          *
1625          * @par Example:
1626          * @code
1627          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1628          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1629          * @endcode
1630          *
1631          * @param string $text The subpage name to add to the title
1632          * @return Title Subpage title
1633          * @since 1.20
1634          */
1635         public function getSubpage( $text ) {
1636                 return self::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1637         }
1638
1639         /**
1640          * Get a URL-encoded form of the subpage text
1641          *
1642          * @return string URL-encoded subpage name
1643          */
1644         public function getSubpageUrlForm() {
1645                 $text = $this->getSubpageText();
1646                 $text = wfUrlencode( strtr( $text, ' ', '_' ) );
1647                 return $text;
1648         }
1649
1650         /**
1651          * Get a URL-encoded title (not an actual URL) including interwiki
1652          *
1653          * @return string The URL-encoded form
1654          */
1655         public function getPrefixedURL() {
1656                 $s = $this->prefix( $this->mDbkeyform );
1657                 $s = wfUrlencode( strtr( $s, ' ', '_' ) );
1658                 return $s;
1659         }
1660
1661         /**
1662          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1663          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1664          * second argument named variant. This was deprecated in favor
1665          * of passing an array of option with a "variant" key
1666          * Once $query2 is removed for good, this helper can be dropped
1667          * and the wfArrayToCgi moved to getLocalURL();
1668          *
1669          * @since 1.19 (r105919)
1670          * @param array|string $query
1671          * @param string|string[]|bool $query2
1672          * @return string
1673          */
1674         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1675                 if ( $query2 !== false ) {
1676                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1677                                 "method called with a second parameter is deprecated. Add your " .
1678                                 "parameter to an array passed as the first parameter.", "1.19" );
1679                 }
1680                 if ( is_array( $query ) ) {
1681                         $query = wfArrayToCgi( $query );
1682                 }
1683                 if ( $query2 ) {
1684                         if ( is_string( $query2 ) ) {
1685                                 // $query2 is a string, we will consider this to be
1686                                 // a deprecated $variant argument and add it to the query
1687                                 $query2 = wfArrayToCgi( [ 'variant' => $query2 ] );
1688                         } else {
1689                                 $query2 = wfArrayToCgi( $query2 );
1690                         }
1691                         // If we have $query content add a & to it first
1692                         if ( $query ) {
1693                                 $query .= '&';
1694                         }
1695                         // Now append the queries together
1696                         $query .= $query2;
1697                 }
1698                 return $query;
1699         }
1700
1701         /**
1702          * Get a real URL referring to this title, with interwiki link and
1703          * fragment
1704          *
1705          * @see self::getLocalURL for the arguments.
1706          * @see wfExpandUrl
1707          * @param string|string[] $query
1708          * @param string|string[]|bool $query2
1709          * @param string $proto Protocol type to use in URL
1710          * @return string The URL
1711          */
1712         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1713                 $query = self::fixUrlQueryArgs( $query, $query2 );
1714
1715                 # Hand off all the decisions on urls to getLocalURL
1716                 $url = $this->getLocalURL( $query );
1717
1718                 # Expand the url to make it a full url. Note that getLocalURL has the
1719                 # potential to output full urls for a variety of reasons, so we use
1720                 # wfExpandUrl instead of simply prepending $wgServer
1721                 $url = wfExpandUrl( $url, $proto );
1722
1723                 # Finally, add the fragment.
1724                 $url .= $this->getFragmentForURL();
1725                 // Avoid PHP 7.1 warning from passing $this by reference
1726                 $titleRef = $this;
1727                 Hooks::run( 'GetFullURL', [ &$titleRef, &$url, $query ] );
1728                 return $url;
1729         }
1730
1731         /**
1732          * Get a url appropriate for making redirects based on an untrusted url arg
1733          *
1734          * This is basically the same as getFullUrl(), but in the case of external
1735          * interwikis, we send the user to a landing page, to prevent possible
1736          * phishing attacks and the like.
1737          *
1738          * @note Uses current protocol by default, since technically relative urls
1739          *   aren't allowed in redirects per HTTP spec, so this is not suitable for
1740          *   places where the url gets cached, as might pollute between
1741          *   https and non-https users.
1742          * @see self::getLocalURL for the arguments.
1743          * @param array|string $query
1744          * @param string $proto Protocol type to use in URL
1745          * @return String. A url suitable to use in an HTTP location header.
1746          */
1747         public function getFullUrlForRedirect( $query = '', $proto = PROTO_CURRENT ) {
1748                 $target = $this;
1749                 if ( $this->isExternal() ) {
1750                         $target = SpecialPage::getTitleFor(
1751                                 'GoToInterwiki',
1752                                 $this->getPrefixedDBKey()
1753                         );
1754                 }
1755                 return $target->getFullUrl( $query, false, $proto );
1756         }
1757
1758         /**
1759          * Get a URL with no fragment or server name (relative URL) from a Title object.
1760          * If this page is generated with action=render, however,
1761          * $wgServer is prepended to make an absolute URL.
1762          *
1763          * @see self::getFullURL to always get an absolute URL.
1764          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1765          *  valid to link, locally, to the current Title.
1766          * @see self::newFromText to produce a Title object.
1767          *
1768          * @param string|string[] $query An optional query string,
1769          *   not used for interwiki links. Can be specified as an associative array as well,
1770          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1771          *   Some query patterns will trigger various shorturl path replacements.
1772          * @param string|string[]|bool $query2 An optional secondary query array. This one MUST
1773          *   be an array. If a string is passed it will be interpreted as a deprecated
1774          *   variant argument and urlencoded into a variant= argument.
1775          *   This second query argument will be added to the $query
1776          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1777          *   pair in the first parameter array instead.
1778          *
1779          * @return string String of the URL.
1780          */
1781         public function getLocalURL( $query = '', $query2 = false ) {
1782                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1783
1784                 $query = self::fixUrlQueryArgs( $query, $query2 );
1785
1786                 $interwiki = self::getInterwikiLookup()->fetch( $this->mInterwiki );
1787                 if ( $interwiki ) {
1788                         $namespace = $this->getNsText();
1789                         if ( $namespace != '' ) {
1790                                 # Can this actually happen? Interwikis shouldn't be parsed.
1791                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1792                                 $namespace .= ':';
1793                         }
1794                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1795                         $url = wfAppendQuery( $url, $query );
1796                 } else {
1797                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1798                         if ( $query == '' ) {
1799                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1800                                 // Avoid PHP 7.1 warning from passing $this by reference
1801                                 $titleRef = $this;
1802                                 Hooks::run( 'GetLocalURL::Article', [ &$titleRef, &$url ] );
1803                         } else {
1804                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1805                                 $url = false;
1806                                 $matches = [];
1807
1808                                 if ( !empty( $wgActionPaths )
1809                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1810                                 ) {
1811                                         $action = urldecode( $matches[2] );
1812                                         if ( isset( $wgActionPaths[$action] ) ) {
1813                                                 $query = $matches[1];
1814                                                 if ( isset( $matches[4] ) ) {
1815                                                         $query .= $matches[4];
1816                                                 }
1817                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1818                                                 if ( $query != '' ) {
1819                                                         $url = wfAppendQuery( $url, $query );
1820                                                 }
1821                                         }
1822                                 }
1823
1824                                 if ( $url === false
1825                                         && $wgVariantArticlePath
1826                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1827                                         && $this->getPageLanguage()->equals( $wgContLang )
1828                                         && $this->getPageLanguage()->hasVariants()
1829                                 ) {
1830                                         $variant = urldecode( $matches[1] );
1831                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1832                                                 // Only do the variant replacement if the given variant is a valid
1833                                                 // variant for the page's language.
1834                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1835                                                 $url = str_replace( '$1', $dbkey, $url );
1836                                         }
1837                                 }
1838
1839                                 if ( $url === false ) {
1840                                         if ( $query == '-' ) {
1841                                                 $query = '';
1842                                         }
1843                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1844                                 }
1845                         }
1846                         // Avoid PHP 7.1 warning from passing $this by reference
1847                         $titleRef = $this;
1848                         Hooks::run( 'GetLocalURL::Internal', [ &$titleRef, &$url, $query ] );
1849
1850                         // @todo FIXME: This causes breakage in various places when we
1851                         // actually expected a local URL and end up with dupe prefixes.
1852                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1853                                 $url = $wgServer . $url;
1854                         }
1855                 }
1856                 // Avoid PHP 7.1 warning from passing $this by reference
1857                 $titleRef = $this;
1858                 Hooks::run( 'GetLocalURL', [ &$titleRef, &$url, $query ] );
1859                 return $url;
1860         }
1861
1862         /**
1863          * Get a URL that's the simplest URL that will be valid to link, locally,
1864          * to the current Title.  It includes the fragment, but does not include
1865          * the server unless action=render is used (or the link is external).  If
1866          * there's a fragment but the prefixed text is empty, we just return a link
1867          * to the fragment.
1868          *
1869          * The result obviously should not be URL-escaped, but does need to be
1870          * HTML-escaped if it's being output in HTML.
1871          *
1872          * @param string|string[] $query
1873          * @param bool $query2
1874          * @param string|int|bool $proto A PROTO_* constant on how the URL should be expanded,
1875          *                               or false (default) for no expansion
1876          * @see self::getLocalURL for the arguments.
1877          * @return string The URL
1878          */
1879         public function getLinkURL( $query = '', $query2 = false, $proto = false ) {
1880                 if ( $this->isExternal() || $proto !== false ) {
1881                         $ret = $this->getFullURL( $query, $query2, $proto );
1882                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1883                         $ret = $this->getFragmentForURL();
1884                 } else {
1885                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1886                 }
1887                 return $ret;
1888         }
1889
1890         /**
1891          * Get the URL form for an internal link.
1892          * - Used in various CDN-related code, in case we have a different
1893          * internal hostname for the server from the exposed one.
1894          *
1895          * This uses $wgInternalServer to qualify the path, or $wgServer
1896          * if $wgInternalServer is not set. If the server variable used is
1897          * protocol-relative, the URL will be expanded to http://
1898          *
1899          * @see self::getLocalURL for the arguments.
1900          * @param string $query
1901          * @param string|bool $query2
1902          * @return string The URL
1903          */
1904         public function getInternalURL( $query = '', $query2 = false ) {
1905                 global $wgInternalServer, $wgServer;
1906                 $query = self::fixUrlQueryArgs( $query, $query2 );
1907                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1908                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1909                 // Avoid PHP 7.1 warning from passing $this by reference
1910                 $titleRef = $this;
1911                 Hooks::run( 'GetInternalURL', [ &$titleRef, &$url, $query ] );
1912                 return $url;
1913         }
1914
1915         /**
1916          * Get the URL for a canonical link, for use in things like IRC and
1917          * e-mail notifications. Uses $wgCanonicalServer and the
1918          * GetCanonicalURL hook.
1919          *
1920          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1921          *
1922          * @see self::getLocalURL for the arguments.
1923          * @return string The URL
1924          * @since 1.18
1925          */
1926         public function getCanonicalURL( $query = '', $query2 = false ) {
1927                 $query = self::fixUrlQueryArgs( $query, $query2 );
1928                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1929                 // Avoid PHP 7.1 warning from passing $this by reference
1930                 $titleRef = $this;
1931                 Hooks::run( 'GetCanonicalURL', [ &$titleRef, &$url, $query ] );
1932                 return $url;
1933         }
1934
1935         /**
1936          * Get the edit URL for this Title
1937          *
1938          * @return string The URL, or a null string if this is an interwiki link
1939          */
1940         public function getEditURL() {
1941                 if ( $this->isExternal() ) {
1942                         return '';
1943                 }
1944                 $s = $this->getLocalURL( 'action=edit' );
1945
1946                 return $s;
1947         }
1948
1949         /**
1950          * Can $user perform $action on this page?
1951          * This skips potentially expensive cascading permission checks
1952          * as well as avoids expensive error formatting
1953          *
1954          * Suitable for use for nonessential UI controls in common cases, but
1955          * _not_ for functional access control.
1956          *
1957          * May provide false positives, but should never provide a false negative.
1958          *
1959          * @param string $action Action that permission needs to be checked for
1960          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1961          * @return bool
1962          */
1963         public function quickUserCan( $action, $user = null ) {
1964                 return $this->userCan( $action, $user, false );
1965         }
1966
1967         /**
1968          * Can $user perform $action on this page?
1969          *
1970          * @param string $action Action that permission needs to be checked for
1971          * @param User $user User to check (since 1.19); $wgUser will be used if not
1972          *   provided.
1973          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1974          * @return bool
1975          */
1976         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1977                 if ( !$user instanceof User ) {
1978                         global $wgUser;
1979                         $user = $wgUser;
1980                 }
1981
1982                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1983         }
1984
1985         /**
1986          * Can $user perform $action on this page?
1987          *
1988          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1989          *
1990          * @param string $action Action that permission needs to be checked for
1991          * @param User $user User to check
1992          * @param string $rigor One of (quick,full,secure)
1993          *   - quick  : does cheap permission checks from replica DBs (usable for GUI creation)
1994          *   - full   : does cheap and expensive checks possibly from a replica DB
1995          *   - secure : does cheap and expensive checks, using the master as needed
1996          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1997          *   whose corresponding errors may be ignored.
1998          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
1999          */
2000         public function getUserPermissionsErrors(
2001                 $action, $user, $rigor = 'secure', $ignoreErrors = []
2002         ) {
2003                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
2004
2005                 // Remove the errors being ignored.
2006                 foreach ( $errors as $index => $error ) {
2007                         $errKey = is_array( $error ) ? $error[0] : $error;
2008
2009                         if ( in_array( $errKey, $ignoreErrors ) ) {
2010                                 unset( $errors[$index] );
2011                         }
2012                         if ( $errKey instanceof MessageSpecifier && in_array( $errKey->getKey(), $ignoreErrors ) ) {
2013                                 unset( $errors[$index] );
2014                         }
2015                 }
2016
2017                 return $errors;
2018         }
2019
2020         /**
2021          * Permissions checks that fail most often, and which are easiest to test.
2022          *
2023          * @param string $action The action to check
2024          * @param User $user User to check
2025          * @param array $errors List of current errors
2026          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2027          * @param bool $short Short circuit on first error
2028          *
2029          * @return array List of errors
2030          */
2031         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
2032                 if ( !Hooks::run( 'TitleQuickPermissions',
2033                         [ $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ] )
2034                 ) {
2035                         return $errors;
2036                 }
2037
2038                 if ( $action == 'create' ) {
2039                         if (
2040                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
2041                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
2042                         ) {
2043                                 $errors[] = $user->isAnon() ? [ 'nocreatetext' ] : [ 'nocreate-loggedin' ];
2044                         }
2045                 } elseif ( $action == 'move' ) {
2046                         if ( !$user->isAllowed( 'move-rootuserpages' )
2047                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
2048                                 // Show user page-specific message only if the user can move other pages
2049                                 $errors[] = [ 'cant-move-user-page' ];
2050                         }
2051
2052                         // Check if user is allowed to move files if it's a file
2053                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
2054                                 $errors[] = [ 'movenotallowedfile' ];
2055                         }
2056
2057                         // Check if user is allowed to move category pages if it's a category page
2058                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
2059                                 $errors[] = [ 'cant-move-category-page' ];
2060                         }
2061
2062                         if ( !$user->isAllowed( 'move' ) ) {
2063                                 // User can't move anything
2064                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
2065                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
2066                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
2067                                         // custom message if logged-in users without any special rights can move
2068                                         $errors[] = [ 'movenologintext' ];
2069                                 } else {
2070                                         $errors[] = [ 'movenotallowed' ];
2071                                 }
2072                         }
2073                 } elseif ( $action == 'move-target' ) {
2074                         if ( !$user->isAllowed( 'move' ) ) {
2075                                 // User can't move anything
2076                                 $errors[] = [ 'movenotallowed' ];
2077                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
2078                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
2079                                 // Show user page-specific message only if the user can move other pages
2080                                 $errors[] = [ 'cant-move-to-user-page' ];
2081                         } elseif ( !$user->isAllowed( 'move-categorypages' )
2082                                         && $this->mNamespace == NS_CATEGORY ) {
2083                                 // Show category page-specific message only if the user can move other pages
2084                                 $errors[] = [ 'cant-move-to-category-page' ];
2085                         }
2086                 } elseif ( !$user->isAllowed( $action ) ) {
2087                         $errors[] = $this->missingPermissionError( $action, $short );
2088                 }
2089
2090                 return $errors;
2091         }
2092
2093         /**
2094          * Add the resulting error code to the errors array
2095          *
2096          * @param array $errors List of current errors
2097          * @param array $result Result of errors
2098          *
2099          * @return array List of errors
2100          */
2101         private function resultToError( $errors, $result ) {
2102                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2103                         // A single array representing an error
2104                         $errors[] = $result;
2105                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2106                         // A nested array representing multiple errors
2107                         $errors = array_merge( $errors, $result );
2108                 } elseif ( $result !== '' && is_string( $result ) ) {
2109                         // A string representing a message-id
2110                         $errors[] = [ $result ];
2111                 } elseif ( $result instanceof MessageSpecifier ) {
2112                         // A message specifier representing an error
2113                         $errors[] = [ $result ];
2114                 } elseif ( $result === false ) {
2115                         // a generic "We don't want them to do that"
2116                         $errors[] = [ 'badaccess-group0' ];
2117                 }
2118                 return $errors;
2119         }
2120
2121         /**
2122          * Check various permission hooks
2123          *
2124          * @param string $action The action to check
2125          * @param User $user User to check
2126          * @param array $errors List of current errors
2127          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2128          * @param bool $short Short circuit on first error
2129          *
2130          * @return array List of errors
2131          */
2132         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2133                 // Use getUserPermissionsErrors instead
2134                 $result = '';
2135                 // Avoid PHP 7.1 warning from passing $this by reference
2136                 $titleRef = $this;
2137                 if ( !Hooks::run( 'userCan', [ &$titleRef, &$user, $action, &$result ] ) ) {
2138                         return $result ? [] : [ [ 'badaccess-group0' ] ];
2139                 }
2140                 // Check getUserPermissionsErrors hook
2141                 // Avoid PHP 7.1 warning from passing $this by reference
2142                 $titleRef = $this;
2143                 if ( !Hooks::run( 'getUserPermissionsErrors', [ &$titleRef, &$user, $action, &$result ] ) ) {
2144                         $errors = $this->resultToError( $errors, $result );
2145                 }
2146                 // Check getUserPermissionsErrorsExpensive hook
2147                 if (
2148                         $rigor !== 'quick'
2149                         && !( $short && count( $errors ) > 0 )
2150                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', [ &$titleRef, &$user, $action, &$result ] )
2151                 ) {
2152                         $errors = $this->resultToError( $errors, $result );
2153                 }
2154
2155                 return $errors;
2156         }
2157
2158         /**
2159          * Check permissions on special pages & namespaces
2160          *
2161          * @param string $action The action to check
2162          * @param User $user User to check
2163          * @param array $errors List of current errors
2164          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2165          * @param bool $short Short circuit on first error
2166          *
2167          * @return array List of errors
2168          */
2169         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2170                 # Only 'createaccount' can be performed on special pages,
2171                 # which don't actually exist in the DB.
2172                 if ( $this->isSpecialPage() && $action !== 'createaccount' ) {
2173                         $errors[] = [ 'ns-specialprotected' ];
2174                 }
2175
2176                 # Check $wgNamespaceProtection for restricted namespaces
2177                 if ( $this->isNamespaceProtected( $user ) ) {
2178                         $ns = $this->mNamespace == NS_MAIN ?
2179                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2180                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2181                                 [ 'protectedinterface', $action ] : [ 'namespaceprotected', $ns, $action ];
2182                 }
2183
2184                 return $errors;
2185         }
2186
2187         /**
2188          * Check CSS/JS sub-page permissions
2189          *
2190          * @param string $action The action to check
2191          * @param User $user User to check
2192          * @param array $errors List of current errors
2193          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2194          * @param bool $short Short circuit on first error
2195          *
2196          * @return array List of errors
2197          */
2198         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2199                 # Protect css/js subpages of user pages
2200                 # XXX: this might be better using restrictions
2201                 if ( $action != 'patrol' ) {
2202                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2203                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2204                                         $errors[] = [ 'mycustomcssprotected', $action ];
2205                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2206                                         $errors[] = [ 'mycustomjsprotected', $action ];
2207                                 }
2208                         } else {
2209                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2210                                         $errors[] = [ 'customcssprotected', $action ];
2211                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2212                                         $errors[] = [ 'customjsprotected', $action ];
2213                                 }
2214                         }
2215                 }
2216
2217                 return $errors;
2218         }
2219
2220         /**
2221          * Check against page_restrictions table requirements on this
2222          * page. The user must possess all required rights for this
2223          * action.
2224          *
2225          * @param string $action The action to check
2226          * @param User $user User to check
2227          * @param array $errors List of current errors
2228          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2229          * @param bool $short Short circuit on first error
2230          *
2231          * @return array List of errors
2232          */
2233         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2234                 foreach ( $this->getRestrictions( $action ) as $right ) {
2235                         // Backwards compatibility, rewrite sysop -> editprotected
2236                         if ( $right == 'sysop' ) {
2237                                 $right = 'editprotected';
2238                         }
2239                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2240                         if ( $right == 'autoconfirmed' ) {
2241                                 $right = 'editsemiprotected';
2242                         }
2243                         if ( $right == '' ) {
2244                                 continue;
2245                         }
2246                         if ( !$user->isAllowed( $right ) ) {
2247                                 $errors[] = [ 'protectedpagetext', $right, $action ];
2248                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2249                                 $errors[] = [ 'protectedpagetext', 'protect', $action ];
2250                         }
2251                 }
2252
2253                 return $errors;
2254         }
2255
2256         /**
2257          * Check restrictions on cascading pages.
2258          *
2259          * @param string $action The action to check
2260          * @param User $user User to check
2261          * @param array $errors List of current errors
2262          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2263          * @param bool $short Short circuit on first error
2264          *
2265          * @return array List of errors
2266          */
2267         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2268                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2269                         # We /could/ use the protection level on the source page, but it's
2270                         # fairly ugly as we have to establish a precedence hierarchy for pages
2271                         # included by multiple cascade-protected pages. So just restrict
2272                         # it to people with 'protect' permission, as they could remove the
2273                         # protection anyway.
2274                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2275                         # Cascading protection depends on more than this page...
2276                         # Several cascading protected pages may include this page...
2277                         # Check each cascading level
2278                         # This is only for protection restrictions, not for all actions
2279                         if ( isset( $restrictions[$action] ) ) {
2280                                 foreach ( $restrictions[$action] as $right ) {
2281                                         // Backwards compatibility, rewrite sysop -> editprotected
2282                                         if ( $right == 'sysop' ) {
2283                                                 $right = 'editprotected';
2284                                         }
2285                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2286                                         if ( $right == 'autoconfirmed' ) {
2287                                                 $right = 'editsemiprotected';
2288                                         }
2289                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2290                                                 $pages = '';
2291                                                 foreach ( $cascadingSources as $page ) {
2292                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2293                                                 }
2294                                                 $errors[] = [ 'cascadeprotected', count( $cascadingSources ), $pages, $action ];
2295                                         }
2296                                 }
2297                         }
2298                 }
2299
2300                 return $errors;
2301         }
2302
2303         /**
2304          * Check action permissions not already checked in checkQuickPermissions
2305          *
2306          * @param string $action The action to check
2307          * @param User $user User to check
2308          * @param array $errors List of current errors
2309          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2310          * @param bool $short Short circuit on first error
2311          *
2312          * @return array List of errors
2313          */
2314         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2315                 global $wgDeleteRevisionsLimit, $wgLang;
2316
2317                 if ( $action == 'protect' ) {
2318                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2319                                 // If they can't edit, they shouldn't protect.
2320                                 $errors[] = [ 'protect-cantedit' ];
2321                         }
2322                 } elseif ( $action == 'create' ) {
2323                         $title_protection = $this->getTitleProtection();
2324                         if ( $title_protection ) {
2325                                 if ( $title_protection['permission'] == ''
2326                                         || !$user->isAllowed( $title_protection['permission'] )
2327                                 ) {
2328                                         $errors[] = [
2329                                                 'titleprotected',
2330                                                 User::whoIs( $title_protection['user'] ),
2331                                                 $title_protection['reason']
2332                                         ];
2333                                 }
2334                         }
2335                 } elseif ( $action == 'move' ) {
2336                         // Check for immobile pages
2337                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2338                                 // Specific message for this case
2339                                 $errors[] = [ 'immobile-source-namespace', $this->getNsText() ];
2340                         } elseif ( !$this->isMovable() ) {
2341                                 // Less specific message for rarer cases
2342                                 $errors[] = [ 'immobile-source-page' ];
2343                         }
2344                 } elseif ( $action == 'move-target' ) {
2345                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2346                                 $errors[] = [ 'immobile-target-namespace', $this->getNsText() ];
2347                         } elseif ( !$this->isMovable() ) {
2348                                 $errors[] = [ 'immobile-target-page' ];
2349                         }
2350                 } elseif ( $action == 'delete' ) {
2351                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, [], $rigor, true );
2352                         if ( !$tempErrors ) {
2353                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2354                                         $user, $tempErrors, $rigor, true );
2355                         }
2356                         if ( $tempErrors ) {
2357                                 // If protection keeps them from editing, they shouldn't be able to delete.
2358                                 $errors[] = [ 'deleteprotected' ];
2359                         }
2360                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2361                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2362                         ) {
2363                                 $errors[] = [ 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) ];
2364                         }
2365                 } elseif ( $action === 'undelete' ) {
2366                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2367                                 // Undeleting implies editing
2368                                 $errors[] = [ 'undelete-cantedit' ];
2369                         }
2370                         if ( !$this->exists()
2371                                 && count( $this->getUserPermissionsErrorsInternal( 'create', $user, $rigor, true ) )
2372                         ) {
2373                                 // Undeleting where nothing currently exists implies creating
2374                                 $errors[] = [ 'undelete-cantcreate' ];
2375                         }
2376                 }
2377                 return $errors;
2378         }
2379
2380         /**
2381          * Check that the user isn't blocked from editing.
2382          *
2383          * @param string $action The action to check
2384          * @param User $user User to check
2385          * @param array $errors List of current errors
2386          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2387          * @param bool $short Short circuit on first error
2388          *
2389          * @return array List of errors
2390          */
2391         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2392                 global $wgEmailConfirmToEdit, $wgBlockDisablesLogin;
2393                 // Account creation blocks handled at userlogin.
2394                 // Unblocking handled in SpecialUnblock
2395                 if ( $rigor === 'quick' || in_array( $action, [ 'createaccount', 'unblock' ] ) ) {
2396                         return $errors;
2397                 }
2398
2399                 // Optimize for a very common case
2400                 if ( $action === 'read' && !$wgBlockDisablesLogin ) {
2401                         return $errors;
2402                 }
2403
2404                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2405                         $errors[] = [ 'confirmedittext' ];
2406                 }
2407
2408                 $useSlave = ( $rigor !== 'secure' );
2409                 if ( ( $action == 'edit' || $action == 'create' )
2410                         && !$user->isBlockedFrom( $this, $useSlave )
2411                 ) {
2412                         // Don't block the user from editing their own talk page unless they've been
2413                         // explicitly blocked from that too.
2414                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2415                         // @todo FIXME: Pass the relevant context into this function.
2416                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2417                 }
2418
2419                 return $errors;
2420         }
2421
2422         /**
2423          * Check that the user is allowed to read this page.
2424          *
2425          * @param string $action The action to check
2426          * @param User $user User to check
2427          * @param array $errors List of current errors
2428          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2429          * @param bool $short Short circuit on first error
2430          *
2431          * @return array List of errors
2432          */
2433         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2434                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2435
2436                 $whitelisted = false;
2437                 if ( User::isEveryoneAllowed( 'read' ) ) {
2438                         # Shortcut for public wikis, allows skipping quite a bit of code
2439                         $whitelisted = true;
2440                 } elseif ( $user->isAllowed( 'read' ) ) {
2441                         # If the user is allowed to read pages, he is allowed to read all pages
2442                         $whitelisted = true;
2443                 } elseif ( $this->isSpecial( 'Userlogin' )
2444                         || $this->isSpecial( 'PasswordReset' )
2445                         || $this->isSpecial( 'Userlogout' )
2446                 ) {
2447                         # Always grant access to the login page.
2448                         # Even anons need to be able to log in.
2449                         $whitelisted = true;
2450                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2451                         # Time to check the whitelist
2452                         # Only do these checks is there's something to check against
2453                         $name = $this->getPrefixedText();
2454                         $dbName = $this->getPrefixedDBkey();
2455
2456                         // Check for explicit whitelisting with and without underscores
2457                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2458                                 $whitelisted = true;
2459                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2460                                 # Old settings might have the title prefixed with
2461                                 # a colon for main-namespace pages
2462                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2463                                         $whitelisted = true;
2464                                 }
2465                         } elseif ( $this->isSpecialPage() ) {
2466                                 # If it's a special page, ditch the subpage bit and check again
2467                                 $name = $this->getDBkey();
2468                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2469                                 if ( $name ) {
2470                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2471                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2472                                                 $whitelisted = true;
2473                                         }
2474                                 }
2475                         }
2476                 }
2477
2478                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2479                         $name = $this->getPrefixedText();
2480                         // Check for regex whitelisting
2481                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2482                                 if ( preg_match( $listItem, $name ) ) {
2483                                         $whitelisted = true;
2484                                         break;
2485                                 }
2486                         }
2487                 }
2488
2489                 if ( !$whitelisted ) {
2490                         # If the title is not whitelisted, give extensions a chance to do so...
2491                         Hooks::run( 'TitleReadWhitelist', [ $this, $user, &$whitelisted ] );
2492                         if ( !$whitelisted ) {
2493                                 $errors[] = $this->missingPermissionError( $action, $short );
2494                         }
2495                 }
2496
2497                 return $errors;
2498         }
2499
2500         /**
2501          * Get a description array when the user doesn't have the right to perform
2502          * $action (i.e. when User::isAllowed() returns false)
2503          *
2504          * @param string $action The action to check
2505          * @param bool $short Short circuit on first error
2506          * @return array Array containing an error message key and any parameters
2507          */
2508         private function missingPermissionError( $action, $short ) {
2509                 // We avoid expensive display logic for quickUserCan's and such
2510                 if ( $short ) {
2511                         return [ 'badaccess-group0' ];
2512                 }
2513
2514                 return User::newFatalPermissionDeniedStatus( $action )->getErrorsArray()[0];
2515         }
2516
2517         /**
2518          * Can $user perform $action on this page? This is an internal function,
2519          * with multiple levels of checks depending on performance needs; see $rigor below.
2520          * It does not check wfReadOnly().
2521          *
2522          * @param string $action Action that permission needs to be checked for
2523          * @param User $user User to check
2524          * @param string $rigor One of (quick,full,secure)
2525          *   - quick  : does cheap permission checks from replica DBs (usable for GUI creation)
2526          *   - full   : does cheap and expensive checks possibly from a replica DB
2527          *   - secure : does cheap and expensive checks, using the master as needed
2528          * @param bool $short Set this to true to stop after the first permission error.
2529          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2530          */
2531         protected function getUserPermissionsErrorsInternal(
2532                 $action, $user, $rigor = 'secure', $short = false
2533         ) {
2534                 if ( $rigor === true ) {
2535                         $rigor = 'secure'; // b/c
2536                 } elseif ( $rigor === false ) {
2537                         $rigor = 'quick'; // b/c
2538                 } elseif ( !in_array( $rigor, [ 'quick', 'full', 'secure' ] ) ) {
2539                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2540                 }
2541
2542                 # Read has special handling
2543                 if ( $action == 'read' ) {
2544                         $checks = [
2545                                 'checkPermissionHooks',
2546                                 'checkReadPermissions',
2547                                 'checkUserBlock', // for wgBlockDisablesLogin
2548                         ];
2549                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2550                 # here as it will lead to duplicate error messages. This is okay to do
2551                 # since anywhere that checks for create will also check for edit, and
2552                 # those checks are called for edit.
2553                 } elseif ( $action == 'create' ) {
2554                         $checks = [
2555                                 'checkQuickPermissions',
2556                                 'checkPermissionHooks',
2557                                 'checkPageRestrictions',
2558                                 'checkCascadingSourcesRestrictions',
2559                                 'checkActionPermissions',
2560                                 'checkUserBlock'
2561                         ];
2562                 } else {
2563                         $checks = [
2564                                 'checkQuickPermissions',
2565                                 'checkPermissionHooks',
2566                                 'checkSpecialsAndNSPermissions',
2567                                 'checkCSSandJSPermissions',
2568                                 'checkPageRestrictions',
2569                                 'checkCascadingSourcesRestrictions',
2570                                 'checkActionPermissions',
2571                                 'checkUserBlock'
2572                         ];
2573                 }
2574
2575                 $errors = [];
2576                 while ( count( $checks ) > 0 &&
2577                                 !( $short && count( $errors ) > 0 ) ) {
2578                         $method = array_shift( $checks );
2579                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2580                 }
2581
2582                 return $errors;
2583         }
2584
2585         /**
2586          * Get a filtered list of all restriction types supported by this wiki.
2587          * @param bool $exists True to get all restriction types that apply to
2588          * titles that do exist, False for all restriction types that apply to
2589          * titles that do not exist
2590          * @return array
2591          */
2592         public static function getFilteredRestrictionTypes( $exists = true ) {
2593                 global $wgRestrictionTypes;
2594                 $types = $wgRestrictionTypes;
2595                 if ( $exists ) {
2596                         # Remove the create restriction for existing titles
2597                         $types = array_diff( $types, [ 'create' ] );
2598                 } else {
2599                         # Only the create and upload restrictions apply to non-existing titles
2600                         $types = array_intersect( $types, [ 'create', 'upload' ] );
2601                 }
2602                 return $types;
2603         }
2604
2605         /**
2606          * Returns restriction types for the current Title
2607          *
2608          * @return array Applicable restriction types
2609          */
2610         public function getRestrictionTypes() {
2611                 if ( $this->isSpecialPage() ) {
2612                         return [];
2613                 }
2614
2615                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2616
2617                 if ( $this->getNamespace() != NS_FILE ) {
2618                         # Remove the upload restriction for non-file titles
2619                         $types = array_diff( $types, [ 'upload' ] );
2620                 }
2621
2622                 Hooks::run( 'TitleGetRestrictionTypes', [ $this, &$types ] );
2623
2624                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2625                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2626
2627                 return $types;
2628         }
2629
2630         /**
2631          * Is this title subject to title protection?
2632          * Title protection is the one applied against creation of such title.
2633          *
2634          * @return array|bool An associative array representing any existent title
2635          *   protection, or false if there's none.
2636          */
2637         public function getTitleProtection() {
2638                 $protection = $this->getTitleProtectionInternal();
2639                 if ( $protection ) {
2640                         if ( $protection['permission'] == 'sysop' ) {
2641                                 $protection['permission'] = 'editprotected'; // B/C
2642                         }
2643                         if ( $protection['permission'] == 'autoconfirmed' ) {
2644                                 $protection['permission'] = 'editsemiprotected'; // B/C
2645                         }
2646                 }
2647                 return $protection;
2648         }
2649
2650         /**
2651          * Fetch title protection settings
2652          *
2653          * To work correctly, $this->loadRestrictions() needs to have access to the
2654          * actual protections in the database without munging 'sysop' =>
2655          * 'editprotected' and 'autoconfirmed' => 'editsemiprotected'. Other
2656          * callers probably want $this->getTitleProtection() instead.
2657          *
2658          * @return array|bool
2659          */
2660         protected function getTitleProtectionInternal() {
2661                 // Can't protect pages in special namespaces
2662                 if ( $this->getNamespace() < 0 ) {
2663                         return false;
2664                 }
2665
2666                 // Can't protect pages that exist.
2667                 if ( $this->exists() ) {
2668                         return false;
2669                 }
2670
2671                 if ( $this->mTitleProtection === null ) {
2672                         $dbr = wfGetDB( DB_REPLICA );
2673                         $res = $dbr->select(
2674                                 'protected_titles',
2675                                 [
2676                                         'user' => 'pt_user',
2677                                         'reason' => 'pt_reason',
2678                                         'expiry' => 'pt_expiry',
2679                                         'permission' => 'pt_create_perm'
2680                                 ],
2681                                 [ 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ],
2682                                 __METHOD__
2683                         );
2684
2685                         // fetchRow returns false if there are no rows.
2686                         $row = $dbr->fetchRow( $res );
2687                         if ( $row ) {
2688                                 $row['expiry'] = $dbr->decodeExpiry( $row['expiry'] );
2689                         }
2690                         $this->mTitleProtection = $row;
2691                 }
2692                 return $this->mTitleProtection;
2693         }
2694
2695         /**
2696          * Remove any title protection due to page existing
2697          */
2698         public function deleteTitleProtection() {
2699                 $dbw = wfGetDB( DB_MASTER );
2700
2701                 $dbw->delete(
2702                         'protected_titles',
2703                         [ 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ],
2704                         __METHOD__
2705                 );
2706                 $this->mTitleProtection = false;
2707         }
2708
2709         /**
2710          * Is this page "semi-protected" - the *only* protection levels are listed
2711          * in $wgSemiprotectedRestrictionLevels?
2712          *
2713          * @param string $action Action to check (default: edit)
2714          * @return bool
2715          */
2716         public function isSemiProtected( $action = 'edit' ) {
2717                 global $wgSemiprotectedRestrictionLevels;
2718
2719                 $restrictions = $this->getRestrictions( $action );
2720                 $semi = $wgSemiprotectedRestrictionLevels;
2721                 if ( !$restrictions || !$semi ) {
2722                         // Not protected, or all protection is full protection
2723                         return false;
2724                 }
2725
2726                 // Remap autoconfirmed to editsemiprotected for BC
2727                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2728                         $semi[$key] = 'editsemiprotected';
2729                 }
2730                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2731                         $restrictions[$key] = 'editsemiprotected';
2732                 }
2733
2734                 return !array_diff( $restrictions, $semi );
2735         }
2736
2737         /**
2738          * Does the title correspond to a protected article?
2739          *
2740          * @param string $action The action the page is protected from,
2741          * by default checks all actions.
2742          * @return bool
2743          */
2744         public function isProtected( $action = '' ) {
2745                 global $wgRestrictionLevels;
2746
2747                 $restrictionTypes = $this->getRestrictionTypes();
2748
2749                 # Special pages have inherent protection
2750                 if ( $this->isSpecialPage() ) {
2751                         return true;
2752                 }
2753
2754                 # Check regular protection levels
2755                 foreach ( $restrictionTypes as $type ) {
2756                         if ( $action == $type || $action == '' ) {
2757                                 $r = $this->getRestrictions( $type );
2758                                 foreach ( $wgRestrictionLevels as $level ) {
2759                                         if ( in_array( $level, $r ) && $level != '' ) {
2760                                                 return true;
2761                                         }
2762                                 }
2763                         }
2764                 }
2765
2766                 return false;
2767         }
2768
2769         /**
2770          * Determines if $user is unable to edit this page because it has been protected
2771          * by $wgNamespaceProtection.
2772          *
2773          * @param User $user User object to check permissions
2774          * @return bool
2775          */
2776         public function isNamespaceProtected( User $user ) {
2777                 global $wgNamespaceProtection;
2778
2779                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2780                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2781                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2782                                         return true;
2783                                 }
2784                         }
2785                 }
2786                 return false;
2787         }
2788
2789         /**
2790          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2791          *
2792          * @return bool If the page is subject to cascading restrictions.
2793          */
2794         public function isCascadeProtected() {
2795                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2796                 return ( $sources > 0 );
2797         }
2798
2799         /**
2800          * Determines whether cascading protection sources have already been loaded from
2801          * the database.
2802          *
2803          * @param bool $getPages True to check if the pages are loaded, or false to check
2804          * if the status is loaded.
2805          * @return bool Whether or not the specified information has been loaded
2806          * @since 1.23
2807          */
2808         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2809                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2810         }
2811
2812         /**
2813          * Cascading protection: Get the source of any cascading restrictions on this page.
2814          *
2815          * @param bool $getPages Whether or not to retrieve the actual pages
2816          *        that the restrictions have come from and the actual restrictions
2817          *        themselves.
2818          * @return array Two elements: First is an array of Title objects of the
2819          *        pages from which cascading restrictions have come, false for
2820          *        none, or true if such restrictions exist but $getPages was not
2821          *        set. Second is an array like that returned by
2822          *        Title::getAllRestrictions(), or an empty array if $getPages is
2823          *        false.
2824          */
2825         public function getCascadeProtectionSources( $getPages = true ) {
2826                 $pagerestrictions = [];
2827
2828                 if ( $this->mCascadeSources !== null && $getPages ) {
2829                         return [ $this->mCascadeSources, $this->mCascadingRestrictions ];
2830                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2831                         return [ $this->mHasCascadingRestrictions, $pagerestrictions ];
2832                 }
2833
2834                 $dbr = wfGetDB( DB_REPLICA );
2835
2836                 if ( $this->getNamespace() == NS_FILE ) {
2837                         $tables = [ 'imagelinks', 'page_restrictions' ];
2838                         $where_clauses = [
2839                                 'il_to' => $this->getDBkey(),
2840                                 'il_from=pr_page',
2841                                 'pr_cascade' => 1
2842                         ];
2843                 } else {
2844                         $tables = [ 'templatelinks', 'page_restrictions' ];
2845                         $where_clauses = [
2846                                 'tl_namespace' => $this->getNamespace(),
2847                                 'tl_title' => $this->getDBkey(),
2848                                 'tl_from=pr_page',
2849                                 'pr_cascade' => 1
2850                         ];
2851                 }
2852
2853                 if ( $getPages ) {
2854                         $cols = [ 'pr_page', 'page_namespace', 'page_title',
2855                                 'pr_expiry', 'pr_type', 'pr_level' ];
2856                         $where_clauses[] = 'page_id=pr_page';
2857                         $tables[] = 'page';
2858                 } else {
2859                         $cols = [ 'pr_expiry' ];
2860                 }
2861
2862                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2863
2864                 $sources = $getPages ? [] : false;
2865                 $now = wfTimestampNow();
2866
2867                 foreach ( $res as $row ) {
2868                         $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2869                         if ( $expiry > $now ) {
2870                                 if ( $getPages ) {
2871                                         $page_id = $row->pr_page;
2872                                         $page_ns = $row->page_namespace;
2873                                         $page_title = $row->page_title;
2874                                         $sources[$page_id] = self::makeTitle( $page_ns, $page_title );
2875                                         # Add groups needed for each restriction type if its not already there
2876                                         # Make sure this restriction type still exists
2877
2878                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2879                                                 $pagerestrictions[$row->pr_type] = [];
2880                                         }
2881
2882                                         if (
2883                                                 isset( $pagerestrictions[$row->pr_type] )
2884                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2885                                         ) {
2886                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2887                                         }
2888                                 } else {
2889                                         $sources = true;
2890                                 }
2891                         }
2892                 }
2893
2894                 if ( $getPages ) {
2895                         $this->mCascadeSources = $sources;
2896                         $this->mCascadingRestrictions = $pagerestrictions;
2897                 } else {
2898                         $this->mHasCascadingRestrictions = $sources;
2899                 }
2900
2901                 return [ $sources, $pagerestrictions ];
2902         }
2903
2904         /**
2905          * Accessor for mRestrictionsLoaded
2906          *
2907          * @return bool Whether or not the page's restrictions have already been
2908          * loaded from the database
2909          * @since 1.23
2910          */
2911         public function areRestrictionsLoaded() {
2912                 return $this->mRestrictionsLoaded;
2913         }
2914
2915         /**
2916          * Accessor/initialisation for mRestrictions
2917          *
2918          * @param string $action Action that permission needs to be checked for
2919          * @return array Restriction levels needed to take the action. All levels are
2920          *     required. Note that restriction levels are normally user rights, but 'sysop'
2921          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2922          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2923          */
2924         public function getRestrictions( $action ) {
2925                 if ( !$this->mRestrictionsLoaded ) {
2926                         $this->loadRestrictions();
2927                 }
2928                 return isset( $this->mRestrictions[$action] )
2929                                 ? $this->mRestrictions[$action]
2930                                 : [];
2931         }
2932
2933         /**
2934          * Accessor/initialisation for mRestrictions
2935          *
2936          * @return array Keys are actions, values are arrays as returned by
2937          *     Title::getRestrictions()
2938          * @since 1.23
2939          */
2940         public function getAllRestrictions() {
2941                 if ( !$this->mRestrictionsLoaded ) {
2942                         $this->loadRestrictions();
2943                 }
2944                 return $this->mRestrictions;
2945         }
2946
2947         /**
2948          * Get the expiry time for the restriction against a given action
2949          *
2950          * @param string $action
2951          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2952          *     or not protected at all, or false if the action is not recognised.
2953          */
2954         public function getRestrictionExpiry( $action ) {
2955                 if ( !$this->mRestrictionsLoaded ) {
2956                         $this->loadRestrictions();
2957                 }
2958                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2959         }
2960
2961         /**
2962          * Returns cascading restrictions for the current article
2963          *
2964          * @return bool
2965          */
2966         function areRestrictionsCascading() {
2967                 if ( !$this->mRestrictionsLoaded ) {
2968                         $this->loadRestrictions();
2969                 }
2970
2971                 return $this->mCascadeRestriction;
2972         }
2973
2974         /**
2975          * Compiles list of active page restrictions from both page table (pre 1.10)
2976          * and page_restrictions table for this existing page.
2977          * Public for usage by LiquidThreads.
2978          *
2979          * @param array $rows Array of db result objects
2980          * @param string $oldFashionedRestrictions Comma-separated list of page
2981          *   restrictions from page table (pre 1.10)
2982          */
2983         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2984                 $dbr = wfGetDB( DB_REPLICA );
2985
2986                 $restrictionTypes = $this->getRestrictionTypes();
2987
2988                 foreach ( $restrictionTypes as $type ) {
2989                         $this->mRestrictions[$type] = [];
2990                         $this->mRestrictionsExpiry[$type] = 'infinity';
2991                 }
2992
2993                 $this->mCascadeRestriction = false;
2994
2995                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2996                 if ( $oldFashionedRestrictions !== null ) {
2997                         $this->mOldRestrictions = $oldFashionedRestrictions;
2998                 }
2999
3000                 if ( $this->mOldRestrictions === false ) {
3001                         $this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
3002                                 [ 'page_id' => $this->getArticleID() ], __METHOD__ );
3003                 }
3004
3005                 if ( $this->mOldRestrictions != '' ) {
3006                         foreach ( explode( ':', trim( $this->mOldRestrictions ) ) as $restrict ) {
3007                                 $temp = explode( '=', trim( $restrict ) );
3008                                 if ( count( $temp ) == 1 ) {
3009                                         // old old format should be treated as edit/move restriction
3010                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
3011                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
3012                                 } else {
3013                                         $restriction = trim( $temp[1] );
3014                                         if ( $restriction != '' ) { // some old entries are empty
3015                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
3016                                         }
3017                                 }
3018                         }
3019                 }
3020
3021                 if ( count( $rows ) ) {
3022                         # Current system - load second to make them override.
3023                         $now = wfTimestampNow();
3024
3025                         # Cycle through all the restrictions.
3026                         foreach ( $rows as $row ) {
3027                                 // Don't take care of restrictions types that aren't allowed
3028                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
3029                                         continue;
3030                                 }
3031
3032                                 $expiry = $dbr->decodeExpiry( $row->pr_expiry );
3033
3034                                 // Only apply the restrictions if they haven't expired!
3035                                 if ( !$expiry || $expiry > $now ) {
3036                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
3037                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
3038
3039                                         $this->mCascadeRestriction |= $row->pr_cascade;
3040                                 }
3041                         }
3042                 }
3043
3044                 $this->mRestrictionsLoaded = true;
3045         }
3046
3047         /**
3048          * Load restrictions from the page_restrictions table
3049          *
3050          * @param string $oldFashionedRestrictions Comma-separated list of page
3051          *   restrictions from page table (pre 1.10)
3052          */
3053         public function loadRestrictions( $oldFashionedRestrictions = null ) {
3054                 if ( $this->mRestrictionsLoaded ) {
3055                         return;
3056                 }
3057
3058                 $id = $this->getArticleID();
3059                 if ( $id ) {
3060                         $cache = ObjectCache::getMainWANInstance();
3061                         $rows = $cache->getWithSetCallback(
3062                                 // Page protections always leave a new null revision
3063                                 $cache->makeKey( 'page-restrictions', $id, $this->getLatestRevID() ),
3064                                 $cache::TTL_DAY,
3065                                 function ( $curValue, &$ttl, array &$setOpts ) {
3066                                         $dbr = wfGetDB( DB_REPLICA );
3067
3068                                         $setOpts += Database::getCacheSetOptions( $dbr );
3069
3070                                         return iterator_to_array(
3071                                                 $dbr->select(
3072                                                         'page_restrictions',
3073                                                         [ 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ],
3074                                                         [ 'pr_page' => $this->getArticleID() ],
3075                                                         __METHOD__
3076                                                 )
3077                                         );
3078                                 }
3079                         );
3080
3081                         $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
3082                 } else {
3083                         $title_protection = $this->getTitleProtectionInternal();
3084
3085                         if ( $title_protection ) {
3086                                 $now = wfTimestampNow();
3087                                 $expiry = wfGetDB( DB_REPLICA )->decodeExpiry( $title_protection['expiry'] );
3088
3089                                 if ( !$expiry || $expiry > $now ) {
3090                                         // Apply the restrictions
3091                                         $this->mRestrictionsExpiry['create'] = $expiry;
3092                                         $this->mRestrictions['create'] =
3093                                                 explode( ',', trim( $title_protection['permission'] ) );
3094                                 } else { // Get rid of the old restrictions
3095                                         $this->mTitleProtection = false;
3096                                 }
3097                         } else {
3098                                 $this->mRestrictionsExpiry['create'] = 'infinity';
3099                         }
3100                         $this->mRestrictionsLoaded = true;
3101                 }
3102         }
3103
3104         /**
3105          * Flush the protection cache in this object and force reload from the database.
3106          * This is used when updating protection from WikiPage::doUpdateRestrictions().
3107          */
3108         public function flushRestrictions() {
3109                 $this->mRestrictionsLoaded = false;
3110                 $this->mTitleProtection = null;
3111         }
3112
3113         /**
3114          * Purge expired restrictions from the page_restrictions table
3115          *
3116          * This will purge no more than $wgUpdateRowsPerQuery page_restrictions rows
3117          */
3118         static function purgeExpiredRestrictions() {
3119                 if ( wfReadOnly() ) {
3120                         return;
3121                 }
3122
3123                 DeferredUpdates::addUpdate( new AtomicSectionUpdate(
3124                         wfGetDB( DB_MASTER ),
3125                         __METHOD__,
3126                         function ( IDatabase $dbw, $fname ) {
3127                                 $config = MediaWikiServices::getInstance()->getMainConfig();
3128                                 $ids = $dbw->selectFieldValues(
3129                                         'page_restrictions',
3130                                         'pr_id',
3131                                         [ 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ],
3132                                         $fname,
3133                                         [ 'LIMIT' => $config->get( 'UpdateRowsPerQuery' ) ] // T135470
3134                                 );
3135                                 if ( $ids ) {
3136                                         $dbw->delete( 'page_restrictions', [ 'pr_id' => $ids ], $fname );
3137                                 }
3138                         }
3139                 ) );
3140
3141                 DeferredUpdates::addUpdate( new AtomicSectionUpdate(
3142                         wfGetDB( DB_MASTER ),
3143                         __METHOD__,
3144                         function ( IDatabase $dbw, $fname ) {
3145                                 $dbw->delete(
3146                                         'protected_titles',
3147                                         [ 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ],
3148                                         $fname
3149                                 );
3150                         }
3151                 ) );
3152         }
3153
3154         /**
3155          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3156          *
3157          * @return bool
3158          */
3159         public function hasSubpages() {
3160                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3161                         # Duh
3162                         return false;
3163                 }
3164
3165                 # We dynamically add a member variable for the purpose of this method
3166                 # alone to cache the result.  There's no point in having it hanging
3167                 # around uninitialized in every Title object; therefore we only add it
3168                 # if needed and don't declare it statically.
3169                 if ( $this->mHasSubpages === null ) {
3170                         $this->mHasSubpages = false;
3171                         $subpages = $this->getSubpages( 1 );
3172                         if ( $subpages instanceof TitleArray ) {
3173                                 $this->mHasSubpages = (bool)$subpages->count();
3174                         }
3175                 }
3176
3177                 return $this->mHasSubpages;
3178         }
3179
3180         /**
3181          * Get all subpages of this page.
3182          *
3183          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3184          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3185          *  doesn't allow subpages
3186          */
3187         public function getSubpages( $limit = -1 ) {
3188                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3189                         return [];
3190                 }
3191
3192                 $dbr = wfGetDB( DB_REPLICA );
3193                 $conds['page_namespace'] = $this->getNamespace();
3194                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3195                 $options = [];
3196                 if ( $limit > -1 ) {
3197                         $options['LIMIT'] = $limit;
3198                 }
3199                 return TitleArray::newFromResult(
3200                         $dbr->select( 'page',
3201                                 [ 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ],
3202                                 $conds,
3203                                 __METHOD__,
3204                                 $options
3205                         )
3206                 );
3207         }
3208
3209         /**
3210          * Is there a version of this page in the deletion archive?
3211          *
3212          * @return int The number of archived revisions
3213          */
3214         public function isDeleted() {
3215                 if ( $this->getNamespace() < 0 ) {
3216                         $n = 0;
3217                 } else {
3218                         $dbr = wfGetDB( DB_REPLICA );
3219
3220                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3221                                 [ 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ],
3222                                 __METHOD__
3223                         );
3224                         if ( $this->getNamespace() == NS_FILE ) {
3225                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3226                                         [ 'fa_name' => $this->getDBkey() ],
3227                                         __METHOD__
3228                                 );
3229                         }
3230                 }
3231                 return (int)$n;
3232         }
3233
3234         /**
3235          * Is there a version of this page in the deletion archive?
3236          *
3237          * @return bool
3238          */
3239         public function isDeletedQuick() {
3240                 if ( $this->getNamespace() < 0 ) {
3241                         return false;
3242                 }
3243                 $dbr = wfGetDB( DB_REPLICA );
3244                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3245                         [ 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ],
3246                         __METHOD__
3247                 );
3248                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3249                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3250                                 [ 'fa_name' => $this->getDBkey() ],
3251                                 __METHOD__
3252                         );
3253                 }
3254                 return $deleted;
3255         }
3256
3257         /**
3258          * Get the article ID for this Title from the link cache,
3259          * adding it if necessary
3260          *
3261          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3262          *  for update
3263          * @return int The ID
3264          */
3265         public function getArticleID( $flags = 0 ) {
3266                 if ( $this->getNamespace() < 0 ) {
3267                         $this->mArticleID = 0;
3268                         return $this->mArticleID;
3269                 }
3270                 $linkCache = LinkCache::singleton();
3271                 if ( $flags & self::GAID_FOR_UPDATE ) {
3272                         $oldUpdate = $linkCache->forUpdate( true );
3273                         $linkCache->clearLink( $this );
3274                         $this->mArticleID = $linkCache->addLinkObj( $this );
3275                         $linkCache->forUpdate( $oldUpdate );
3276                 } else {
3277                         if ( -1 == $this->mArticleID ) {
3278                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3279                         }
3280                 }
3281                 return $this->mArticleID;
3282         }
3283
3284         /**
3285          * Is this an article that is a redirect page?
3286          * Uses link cache, adding it if necessary
3287          *
3288          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3289          * @return bool
3290          */
3291         public function isRedirect( $flags = 0 ) {
3292                 if ( !is_null( $this->mRedirect ) ) {
3293                         return $this->mRedirect;
3294                 }
3295                 if ( !$this->getArticleID( $flags ) ) {
3296                         $this->mRedirect = false;
3297                         return $this->mRedirect;
3298                 }
3299
3300                 $linkCache = LinkCache::singleton();
3301                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3302                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3303                 if ( $cached === null ) {
3304                         # Trust LinkCache's state over our own
3305                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3306                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3307                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3308                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3309                         # LinkCache to refresh its data from the master.
3310                         $this->mRedirect = false;
3311                         return $this->mRedirect;
3312                 }
3313
3314                 $this->mRedirect = (bool)$cached;
3315
3316                 return $this->mRedirect;
3317         }
3318
3319         /**
3320          * What is the length of this page?
3321          * Uses link cache, adding it if necessary
3322          *
3323          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3324          * @return int
3325          */
3326         public function getLength( $flags = 0 ) {
3327                 if ( $this->mLength != -1 ) {
3328                         return $this->mLength;
3329                 }
3330                 if ( !$this->getArticleID( $flags ) ) {
3331                         $this->mLength = 0;
3332                         return $this->mLength;
3333                 }
3334                 $linkCache = LinkCache::singleton();
3335                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3336                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3337                 if ( $cached === null ) {
3338                         # Trust LinkCache's state over our own, as for isRedirect()
3339                         $this->mLength = 0;
3340                         return $this->mLength;
3341                 }
3342
3343                 $this->mLength = intval( $cached );
3344
3345                 return $this->mLength;
3346         }
3347
3348         /**
3349          * What is the page_latest field for this page?
3350          *
3351          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3352          * @return int Int or 0 if the page doesn't exist
3353          */
3354         public function getLatestRevID( $flags = 0 ) {
3355                 if ( !( $flags & self::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3356                         return intval( $this->mLatestID );
3357                 }
3358                 if ( !$this->getArticleID( $flags ) ) {
3359                         $this->mLatestID = 0;
3360                         return $this->mLatestID;
3361                 }
3362                 $linkCache = LinkCache::singleton();
3363                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3364                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3365                 if ( $cached === null ) {
3366                         # Trust LinkCache's state over our own, as for isRedirect()
3367                         $this->mLatestID = 0;
3368                         return $this->mLatestID;
3369                 }
3370
3371                 $this->mLatestID = intval( $cached );
3372
3373                 return $this->mLatestID;
3374         }
3375
3376         /**
3377          * This clears some fields in this object, and clears any associated
3378          * keys in the "bad links" section of the link cache.
3379          *
3380          * - This is called from WikiPage::doEditContent() and WikiPage::insertOn() to allow
3381          * loading of the new page_id. It's also called from
3382          * WikiPage::doDeleteArticleReal()
3383          *
3384          * @param int $newid The new Article ID
3385          */
3386         public function resetArticleID( $newid ) {
3387                 $linkCache = LinkCache::singleton();
3388                 $linkCache->clearLink( $this );
3389
3390                 if ( $newid === false ) {
3391                         $this->mArticleID = -1;
3392                 } else {
3393                         $this->mArticleID = intval( $newid );
3394                 }
3395                 $this->mRestrictionsLoaded = false;
3396                 $this->mRestrictions = [];
3397                 $this->mOldRestrictions = false;
3398                 $this->mRedirect = null;
3399                 $this->mLength = -1;
3400                 $this->mLatestID = false;
3401                 $this->mContentModel = false;
3402                 $this->mEstimateRevisions = null;
3403                 $this->mPageLanguage = false;
3404                 $this->mDbPageLanguage = false;
3405                 $this->mIsBigDeletion = null;
3406         }
3407
3408         public static function clearCaches() {
3409                 $linkCache = LinkCache::singleton();
3410                 $linkCache->clear();
3411
3412                 $titleCache = self::getTitleCache();
3413                 $titleCache->clear();
3414         }
3415
3416         /**
3417          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3418          *
3419          * @param string $text Containing title to capitalize
3420          * @param int $ns Namespace index, defaults to NS_MAIN
3421          * @return string Containing capitalized title
3422          */
3423         public static function capitalize( $text, $ns = NS_MAIN ) {
3424                 global $wgContLang;
3425
3426                 if ( MWNamespace::isCapitalized( $ns ) ) {
3427                         return $wgContLang->ucfirst( $text );
3428                 } else {
3429                         return $text;
3430                 }
3431         }
3432
3433         /**
3434          * Secure and split - main initialisation function for this object
3435          *
3436          * Assumes that mDbkeyform has been set, and is urldecoded
3437          * and uses underscores, but not otherwise munged.  This function
3438          * removes illegal characters, splits off the interwiki and
3439          * namespace prefixes, sets the other forms, and canonicalizes
3440          * everything.
3441          *
3442          * @throws MalformedTitleException On invalid titles
3443          * @return bool True on success
3444          */
3445         private function secureAndSplit() {
3446                 # Initialisation
3447                 $this->mInterwiki = '';
3448                 $this->mFragment = '';
3449                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3450
3451                 $dbkey = $this->mDbkeyform;
3452
3453                 // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3454                 //        the parsing code with Title, while avoiding massive refactoring.
3455                 // @todo: get rid of secureAndSplit, refactor parsing code.
3456                 // @note: getTitleParser() returns a TitleParser implementation which does not have a
3457                 //        splitTitleString method, but the only implementation (MediaWikiTitleCodec) does
3458                 $titleCodec = MediaWikiServices::getInstance()->getTitleParser();
3459                 // MalformedTitleException can be thrown here
3460                 $parts = $titleCodec->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3461
3462                 # Fill fields
3463                 $this->setFragment( '#' . $parts['fragment'] );
3464                 $this->mInterwiki = $parts['interwiki'];
3465                 $this->mLocalInterwiki = $parts['local_interwiki'];
3466                 $this->mNamespace = $parts['namespace'];
3467                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3468
3469                 $this->mDbkeyform = $parts['dbkey'];
3470                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3471                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
3472
3473                 # We already know that some pages won't be in the database!
3474                 if ( $this->isExternal() || $this->isSpecialPage() ) {
3475                         $this->mArticleID = 0;
3476                 }
3477
3478                 return true;
3479         }
3480
3481         /**
3482          * Get an array of Title objects linking to this Title
3483          * Also stores the IDs in the link cache.
3484          *
3485          * WARNING: do not use this function on arbitrary user-supplied titles!
3486          * On heavily-used templates it will max out the memory.
3487          *
3488          * @param array $options May be FOR UPDATE
3489          * @param string $table Table name
3490          * @param string $prefix Fields prefix
3491          * @return Title[] Array of Title objects linking here
3492          */
3493         public function getLinksTo( $options = [], $table = 'pagelinks', $prefix = 'pl' ) {
3494                 if ( count( $options ) > 0 ) {
3495                         $db = wfGetDB( DB_MASTER );
3496                 } else {
3497                         $db = wfGetDB( DB_REPLICA );
3498                 }
3499
3500                 $res = $db->select(
3501                         [ 'page', $table ],
3502                         self::getSelectFields(),
3503                         [
3504                                 "{$prefix}_from=page_id",
3505                                 "{$prefix}_namespace" => $this->getNamespace(),
3506                                 "{$prefix}_title" => $this->getDBkey() ],
3507                         __METHOD__,
3508                         $options
3509                 );
3510
3511                 $retVal = [];
3512                 if ( $res->numRows() ) {
3513                         $linkCache = LinkCache::singleton();
3514                         foreach ( $res as $row ) {
3515                                 $titleObj = self::makeTitle( $row->page_namespace, $row->page_title );
3516                                 if ( $titleObj ) {
3517                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3518                                         $retVal[] = $titleObj;
3519                                 }
3520                         }
3521                 }
3522                 return $retVal;
3523         }
3524
3525         /**
3526          * Get an array of Title objects using this Title as a template
3527          * Also stores the IDs in the link cache.
3528          *
3529          * WARNING: do not use this function on arbitrary user-supplied titles!
3530          * On heavily-used templates it will max out the memory.
3531          *
3532          * @param array $options Query option to Database::select()
3533          * @return Title[] Array of Title the Title objects linking here
3534          */
3535         public function getTemplateLinksTo( $options = [] ) {
3536                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3537         }
3538
3539         /**
3540          * Get an array of Title objects linked from this Title
3541          * Also stores the IDs in the link cache.
3542          *
3543          * WARNING: do not use this function on arbitrary user-supplied titles!
3544          * On heavily-used templates it will max out the memory.
3545          *
3546          * @param array $options Query option to Database::select()
3547          * @param string $table Table name
3548          * @param string $prefix Fields prefix
3549          * @return array Array of Title objects linking here
3550          */
3551         public function getLinksFrom( $options = [], $table = 'pagelinks', $prefix = 'pl' ) {
3552                 $id = $this->getArticleID();
3553
3554                 # If the page doesn't exist; there can't be any link from this page
3555                 if ( !$id ) {
3556                         return [];
3557                 }
3558
3559                 $db = wfGetDB( DB_REPLICA );
3560
3561                 $blNamespace = "{$prefix}_namespace";
3562                 $blTitle = "{$prefix}_title";
3563
3564                 $res = $db->select(
3565                         [ $table, 'page' ],
3566                         array_merge(
3567                                 [ $blNamespace, $blTitle ],
3568                                 WikiPage::selectFields()
3569                         ),
3570                         [ "{$prefix}_from" => $id ],
3571                         __METHOD__,
3572                         $options,
3573                         [ 'page' => [
3574                                 'LEFT JOIN',
3575                                 [ "page_namespace=$blNamespace", "page_title=$blTitle" ]
3576                         ] ]
3577                 );
3578
3579                 $retVal = [];
3580                 $linkCache = LinkCache::singleton();
3581                 foreach ( $res as $row ) {
3582                         if ( $row->page_id ) {
3583                                 $titleObj = self::newFromRow( $row );
3584                         } else {
3585                                 $titleObj = self::makeTitle( $row->$blNamespace, $row->$blTitle );
3586                                 $linkCache->addBadLinkObj( $titleObj );
3587                         }
3588                         $retVal[] = $titleObj;
3589                 }
3590
3591                 return $retVal;
3592         }
3593
3594         /**
3595          * Get an array of Title objects used on this Title as a template
3596          * Also stores the IDs in the link cache.
3597          *
3598          * WARNING: do not use this function on arbitrary user-supplied titles!
3599          * On heavily-used templates it will max out the memory.
3600          *
3601          * @param array $options May be FOR UPDATE
3602          * @return Title[] Array of Title the Title objects used here
3603          */
3604         public function getTemplateLinksFrom( $options = [] ) {
3605                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3606         }
3607
3608         /**
3609          * Get an array of Title objects referring to non-existent articles linked
3610          * from this page.
3611          *
3612          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3613          *   should use redirect table in this case).
3614          * @return Title[] Array of Title the Title objects
3615          */
3616         public function getBrokenLinksFrom() {
3617                 if ( $this->getArticleID() == 0 ) {
3618                         # All links from article ID 0 are false positives
3619                         return [];
3620                 }
3621
3622                 $dbr = wfGetDB( DB_REPLICA );
3623                 $res = $dbr->select(
3624                         [ 'page', 'pagelinks' ],
3625                         [ 'pl_namespace', 'pl_title' ],
3626                         [
3627                                 'pl_from' => $this->getArticleID(),
3628                                 'page_namespace IS NULL'
3629                         ],
3630                         __METHOD__, [],
3631                         [
3632                                 'page' => [
3633                                         'LEFT JOIN',
3634                                         [ 'pl_namespace=page_namespace', 'pl_title=page_title' ]
3635                                 ]
3636                         ]
3637                 );
3638
3639                 $retVal = [];
3640                 foreach ( $res as $row ) {
3641                         $retVal[] = self::makeTitle( $row->pl_namespace, $row->pl_title );
3642                 }
3643                 return $retVal;
3644         }
3645
3646         /**
3647          * Get a list of URLs to purge from the CDN cache when this
3648          * page changes
3649          *
3650          * @return string[] Array of String the URLs
3651          */
3652         public function getCdnUrls() {
3653                 $urls = [
3654                         $this->getInternalURL(),
3655                         $this->getInternalURL( 'action=history' )
3656                 ];
3657
3658                 $pageLang = $this->getPageLanguage();
3659                 if ( $pageLang->hasVariants() ) {
3660                         $variants = $pageLang->getVariants();
3661                         foreach ( $variants as $vCode ) {
3662                                 $urls[] = $this->getInternalURL( $vCode );
3663                         }
3664                 }
3665
3666                 // If we are looking at a css/js user subpage, purge the action=raw.
3667                 if ( $this->isJsSubpage() ) {
3668                         $urls[] = $this->getInternalURL( 'action=raw&ctype=text/javascript' );
3669                 } elseif ( $this->isCssSubpage() ) {
3670                         $urls[] = $this->getInternalURL( 'action=raw&ctype=text/css' );
3671                 }
3672
3673                 Hooks::run( 'TitleSquidURLs', [ $this, &$urls ] );
3674                 return $urls;
3675         }
3676
3677         /**
3678          * @deprecated since 1.27 use getCdnUrls()
3679          */
3680         public function getSquidURLs() {
3681                 return $this->getCdnUrls();
3682         }
3683
3684         /**
3685          * Purge all applicable CDN URLs
3686          */
3687         public function purgeSquid() {
3688                 DeferredUpdates::addUpdate(
3689                         new CdnCacheUpdate( $this->getCdnUrls() ),
3690                         DeferredUpdates::PRESEND
3691                 );
3692         }
3693
3694         /**
3695          * Check whether a given move operation would be valid.
3696          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3697          *
3698          * @deprecated since 1.25, use MovePage's methods instead
3699          * @param Title &$nt The new title
3700          * @param bool $auth Whether to check user permissions (uses $wgUser)
3701          * @param string $reason Is the log summary of the move, used for spam checking
3702          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3703          */
3704         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3705                 global $wgUser;
3706
3707                 if ( !( $nt instanceof Title ) ) {
3708                         // Normally we'd add this to $errors, but we'll get
3709                         // lots of syntax errors if $nt is not an object
3710                         return [ [ 'badtitletext' ] ];
3711                 }
3712
3713                 $mp = new MovePage( $this, $nt );
3714                 $errors = $mp->isValidMove()->getErrorsArray();
3715                 if ( $auth ) {
3716                         $errors = wfMergeErrorArrays(
3717                                 $errors,
3718                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3719                         );
3720                 }
3721
3722                 return $errors ?: true;
3723         }
3724
3725         /**
3726          * Check if the requested move target is a valid file move target
3727          * @todo move this to MovePage
3728          * @param Title $nt Target title
3729          * @return array List of errors
3730          */
3731         protected function validateFileMoveOperation( $nt ) {
3732                 global $wgUser;
3733
3734                 $errors = [];
3735
3736                 $destFile = wfLocalFile( $nt );
3737                 $destFile->load( File::READ_LATEST );
3738                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3739                         && !$destFile->exists() && wfFindFile( $nt )
3740                 ) {
3741                         $errors[] = [ 'file-exists-sharedrepo' ];
3742                 }
3743
3744                 return $errors;
3745         }
3746
3747         /**
3748          * Move a title to a new location
3749          *
3750          * @deprecated since 1.25, use the MovePage class instead
3751          * @param Title &$nt The new title
3752          * @param bool $auth Indicates whether $wgUser's permissions
3753          *  should be checked
3754          * @param string $reason The reason for the move
3755          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3756          *  Ignored if the user doesn't have the suppressredirect right.
3757          * @param array $changeTags Applied to the entry in the move log and redirect page revision
3758          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3759          */
3760         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true,
3761                 array $changeTags = []
3762         ) {
3763                 global $wgUser;
3764                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3765                 if ( is_array( $err ) ) {
3766                         // Auto-block user's IP if the account was "hard" blocked
3767                         $wgUser->spreadAnyEditBlock();
3768                         return $err;
3769                 }
3770                 // Check suppressredirect permission
3771                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3772                         $createRedirect = true;
3773                 }
3774
3775                 $mp = new MovePage( $this, $nt );
3776                 $status = $mp->move( $wgUser, $reason, $createRedirect, $changeTags );
3777                 if ( $status->isOK() ) {
3778                         return true;
3779                 } else {
3780                         return $status->getErrorsArray();
3781                 }
3782         }
3783
3784         /**
3785          * Move this page's subpages to be subpages of $nt
3786          *
3787          * @param Title $nt Move target
3788          * @param bool $auth Whether $wgUser's permissions should be checked
3789          * @param string $reason The reason for the move
3790          * @param bool $createRedirect Whether to create redirects from the old subpages to
3791          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3792          * @param array $changeTags Applied to the entry in the move log and redirect page revision
3793          * @return array Array with old page titles as keys, and strings (new page titles) or
3794          *     getUserPermissionsErrors()-like arrays (errors) as values, or a
3795          *     getUserPermissionsErrors()-like error array with numeric indices if
3796          *     no pages were moved
3797          */
3798         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true,
3799                 array $changeTags = []
3800         ) {
3801                 global $wgMaximumMovedPages;
3802                 // Check permissions
3803                 if ( !$this->userCan( 'move-subpages' ) ) {
3804                         return [
3805                                 [ 'cant-move-subpages' ],
3806                         ];
3807                 }
3808                 // Do the source and target namespaces support subpages?
3809                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3810                         return [
3811                                 [ 'namespace-nosubpages', MWNamespace::getCanonicalName( $this->getNamespace() ) ],
3812                         ];
3813                 }
3814                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3815                         return [
3816                                 [ 'namespace-nosubpages', MWNamespace::getCanonicalName( $nt->getNamespace() ) ],
3817                         ];
3818                 }
3819
3820                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3821                 $retval = [];
3822                 $count = 0;
3823                 foreach ( $subpages as $oldSubpage ) {
3824                         $count++;
3825                         if ( $count > $wgMaximumMovedPages ) {
3826                                 $retval[$oldSubpage->getPrefixedText()] = [
3827                                         [ 'movepage-max-pages', $wgMaximumMovedPages ],
3828                                 ];
3829                                 break;
3830                         }
3831
3832                         // We don't know whether this function was called before
3833                         // or after moving the root page, so check both
3834                         // $this and $nt
3835                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3836                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3837                         ) {
3838                                 // When moving a page to a subpage of itself,
3839                                 // don't move it twice
3840                                 continue;
3841                         }
3842                         $newPageName = preg_replace(
3843                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3844                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # T23234
3845                                         $oldSubpage->getDBkey() );
3846                         if ( $oldSubpage->isTalkPage() ) {
3847                                 $newNs = $nt->getTalkPage()->getNamespace();
3848                         } else {
3849                                 $newNs = $nt->getSubjectPage()->getNamespace();
3850                         }
3851                         # T16385: we need makeTitleSafe because the new page names may
3852                         # be longer than 255 characters.
3853                         $newSubpage = self::makeTitleSafe( $newNs, $newPageName );
3854
3855                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect, $changeTags );
3856                         if ( $success === true ) {
3857                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3858                         } else {
3859                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3860                         }
3861                 }
3862                 return $retval;
3863         }
3864
3865         /**
3866          * Checks if this page is just a one-rev redirect.
3867          * Adds lock, so don't use just for light purposes.
3868          *
3869          * @return bool
3870          */
3871         public function isSingleRevRedirect() {
3872                 global $wgContentHandlerUseDB;
3873
3874                 $dbw = wfGetDB( DB_MASTER );
3875
3876                 # Is it a redirect?
3877                 $fields = [ 'page_is_redirect', 'page_latest', 'page_id' ];
3878                 if ( $wgContentHandlerUseDB ) {
3879                         $fields[] = 'page_content_model';
3880                 }
3881
3882                 $row = $dbw->selectRow( 'page',
3883                         $fields,
3884                         $this->pageCond(),
3885                         __METHOD__,
3886                         [ 'FOR UPDATE' ]
3887                 );
3888                 # Cache some fields we may want
3889                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3890                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3891                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3892                 $this->mContentModel = $row && isset( $row->page_content_model )
3893                         ? strval( $row->page_content_model )
3894                         : false;
3895
3896                 if ( !$this->mRedirect ) {
3897                         return false;
3898                 }
3899                 # Does the article have a history?
3900                 $row = $dbw->selectField( [ 'page', 'revision' ],
3901                         'rev_id',
3902                         [ 'page_namespace' => $this->getNamespace(),
3903                                 'page_title' => $this->getDBkey(),
3904                                 'page_id=rev_page',
3905                                 'page_latest != rev_id'
3906                         ],
3907                         __METHOD__,
3908                         [ 'FOR UPDATE' ]
3909                 );
3910                 # Return true if there was no history
3911                 return ( $row === false );
3912         }
3913
3914         /**
3915          * Checks if $this can be moved to a given Title
3916          * - Selects for update, so don't call it unless you mean business
3917          *
3918          * @deprecated since 1.25, use MovePage's methods instead
3919          * @param Title $nt The new title to check
3920          * @return bool
3921          */
3922         public function isValidMoveTarget( $nt ) {
3923                 # Is it an existing file?
3924                 if ( $nt->getNamespace() == NS_FILE ) {
3925                         $file = wfLocalFile( $nt );
3926                         $file->load( File::READ_LATEST );
3927                         if ( $file->exists() ) {
3928                                 wfDebug( __METHOD__ . ": file exists\n" );
3929                                 return false;
3930                         }
3931                 }
3932                 # Is it a redirect with no history?
3933                 if ( !$nt->isSingleRevRedirect() ) {
3934                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3935                         return false;
3936                 }
3937                 # Get the article text
3938                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3939                 if ( !is_object( $rev ) ) {
3940                         return false;
3941                 }
3942                 $content = $rev->getContent();
3943                 # Does the redirect point to the source?
3944                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3945                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3946
3947                 if ( $redirTitle ) {
3948                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3949                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3950                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3951                                 return false;
3952                         } else {
3953                                 return true;
3954                         }
3955                 } else {
3956                         # Fail safe (not a redirect after all. strange.)
3957                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3958                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3959                         return false;
3960                 }
3961         }
3962
3963         /**
3964          * Get categories to which this Title belongs and return an array of
3965          * categories' names.
3966          *
3967          * @return array Array of parents in the form:
3968          *     $parent => $currentarticle
3969          */
3970         public function getParentCategories() {
3971                 global $wgContLang;
3972
3973                 $data = [];
3974
3975                 $titleKey = $this->getArticleID();
3976
3977                 if ( $titleKey === 0 ) {
3978                         return $data;
3979                 }
3980
3981                 $dbr = wfGetDB( DB_REPLICA );
3982
3983                 $res = $dbr->select(
3984                         'categorylinks',
3985                         'cl_to',
3986                         [ 'cl_from' => $titleKey ],
3987                         __METHOD__
3988                 );
3989
3990                 if ( $res->numRows() > 0 ) {
3991                         foreach ( $res as $row ) {
3992                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3993                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3994                         }
3995                 }
3996                 return $data;
3997         }
3998
3999         /**
4000          * Get a tree of parent categories
4001          *
4002          * @param array $children Array with the children in the keys, to check for circular refs
4003          * @return array Tree of parent categories
4004          */
4005         public function getParentCategoryTree( $children = [] ) {
4006                 $stack = [];
4007                 $parents = $this->getParentCategories();
4008
4009                 if ( $parents ) {
4010                         foreach ( $parents as $parent => $current ) {
4011                                 if ( array_key_exists( $parent, $children ) ) {
4012                                         # Circular reference
4013                                         $stack[$parent] = [];
4014                                 } else {
4015                                         $nt = self::newFromText( $parent );
4016                                         if ( $nt ) {
4017                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + [ $parent => 1 ] );
4018                                         }
4019                                 }
4020                         }
4021                 }
4022
4023                 return $stack;
4024         }
4025
4026         /**
4027          * Get an associative array for selecting this title from
4028          * the "page" table
4029          *
4030          * @return array Array suitable for the $where parameter of DB::select()
4031          */
4032         public function pageCond() {
4033                 if ( $this->mArticleID > 0 ) {
4034                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4035                         return [ 'page_id' => $this->mArticleID ];
4036                 } else {
4037                         return [ 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform ];
4038                 }
4039         }
4040
4041         /**
4042          * Get next/previous revision ID relative to another revision ID
4043          * @param int $revId Revision ID. Get the revision that was before this one.
4044          * @param int $flags Title::GAID_FOR_UPDATE
4045          * @param string $dir 'next' or 'prev'
4046          * @return int|bool New revision ID, or false if none exists
4047          */
4048         private function getRelativeRevisionID( $revId, $flags, $dir ) {
4049                 $revId = (int)$revId;
4050                 if ( $dir === 'next' ) {
4051                         $op = '>';
4052                         $sort = 'ASC';
4053                 } elseif ( $dir === 'prev' ) {
4054                         $op = '<';
4055                         $sort = 'DESC';
4056                 } else {
4057                         throw new InvalidArgumentException( '$dir must be "next" or "prev"' );
4058                 }
4059
4060                 if ( $flags & self::GAID_FOR_UPDATE ) {
4061                         $db = wfGetDB( DB_MASTER );
4062                 } else {
4063                         $db = wfGetDB( DB_REPLICA, 'contributions' );
4064                 }
4065
4066                 // Intentionally not caring if the specified revision belongs to this
4067                 // page. We only care about the timestamp.
4068                 $ts = $db->selectField( 'revision', 'rev_timestamp', [ 'rev_id' => $revId ], __METHOD__ );
4069                 if ( $ts === false ) {
4070                         $ts = $db->selectField( 'archive', 'ar_timestamp', [ 'ar_rev_id' => $revId ], __METHOD__ );
4071                         if ( $ts === false ) {
4072                                 // Or should this throw an InvalidArgumentException or something?
4073                                 return false;
4074                         }
4075                 }
4076                 $ts = $db->addQuotes( $ts );
4077
4078                 $revId = $db->selectField( 'revision', 'rev_id',
4079                         [
4080                                 'rev_page' => $this->getArticleID( $flags ),
4081                                 "rev_timestamp $op $ts OR (rev_timestamp = $ts AND rev_id $op $revId)"
4082                         ],
4083                         __METHOD__,
4084                         [
4085                                 'ORDER BY' => "rev_timestamp $sort, rev_id $sort",
4086                                 'IGNORE INDEX' => 'rev_timestamp', // Probably needed for T159319
4087                         ]
4088                 );
4089
4090                 if ( $revId === false ) {
4091                         return false;
4092                 } else {
4093                         return intval( $revId );
4094                 }
4095         }
4096
4097         /**
4098          * Get the revision ID of the previous revision
4099          *
4100          * @param int $revId Revision ID. Get the revision that was before this one.
4101          * @param int $flags Title::GAID_FOR_UPDATE
4102          * @return int|bool Old revision ID, or false if none exists
4103          */
4104         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4105                 return $this->getRelativeRevisionID( $revId, $flags, 'prev' );
4106         }
4107
4108         /**
4109          * Get the revision ID of the next revision
4110          *
4111          * @param int $revId Revision ID. Get the revision that was after this one.
4112          * @param int $flags Title::GAID_FOR_UPDATE
4113          * @return int|bool Next revision ID, or false if none exists
4114          */
4115         public function getNextRevisionID( $revId, $flags = 0 ) {
4116                 return $this->getRelativeRevisionID( $revId, $flags, 'next' );
4117         }
4118
4119         /**
4120          * Get the first revision of the page
4121          *
4122          * @param int $flags Title::GAID_FOR_UPDATE
4123          * @return Revision|null If page doesn't exist
4124          */
4125         public function getFirstRevision( $flags = 0 ) {
4126                 $pageId = $this->getArticleID( $flags );
4127                 if ( $pageId ) {
4128                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_REPLICA );
4129                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4130                                 [ 'rev_page' => $pageId ],
4131                                 __METHOD__,
4132                                 [
4133                                         'ORDER BY' => 'rev_timestamp ASC, rev_id ASC',
4134                                         'IGNORE INDEX' => 'rev_timestamp', // See T159319
4135                                 ]
4136                         );
4137                         if ( $row ) {
4138                                 return new Revision( $row );
4139                         }
4140                 }
4141                 return null;
4142         }
4143
4144         /**
4145          * Get the oldest revision timestamp of this page
4146          *
4147          * @param int $flags Title::GAID_FOR_UPDATE
4148          * @return string MW timestamp
4149          */
4150         public function getEarliestRevTime( $flags = 0 ) {
4151                 $rev = $this->getFirstRevision( $flags );
4152                 return $rev ? $rev->getTimestamp() : null;
4153         }
4154
4155         /**
4156          * Check if this is a new page
4157          *
4158          * @return bool
4159          */
4160         public function isNewPage() {
4161                 $dbr = wfGetDB( DB_REPLICA );
4162                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4163         }
4164
4165         /**
4166          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4167          *
4168          * @return bool
4169          */
4170         public function isBigDeletion() {
4171                 global $wgDeleteRevisionsLimit;
4172
4173                 if ( !$wgDeleteRevisionsLimit ) {
4174                         return false;
4175                 }
4176
4177                 if ( $this->mIsBigDeletion === null ) {
4178                         $dbr = wfGetDB( DB_REPLICA );
4179
4180                         $revCount = $dbr->selectRowCount(
4181                                 'revision',
4182                                 '1',
4183                                 [ 'rev_page' => $this->getArticleID() ],
4184                                 __METHOD__,
4185                                 [ 'LIMIT' => $wgDeleteRevisionsLimit + 1 ]
4186                         );
4187
4188                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4189                 }
4190
4191                 return $this->mIsBigDeletion;
4192         }
4193
4194         /**
4195          * Get the approximate revision count of this page.
4196          *
4197          * @return int
4198          */
4199         public function estimateRevisionCount() {
4200                 if ( !$this->exists() ) {
4201                         return 0;
4202                 }
4203
4204                 if ( $this->mEstimateRevisions === null ) {
4205                         $dbr = wfGetDB( DB_REPLICA );
4206                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4207                                 [ 'rev_page' => $this->getArticleID() ], __METHOD__ );
4208                 }
4209
4210                 return $this->mEstimateRevisions;
4211         }
4212
4213         /**
4214          * Get the number of revisions between the given revision.
4215          * Used for diffs and other things that really need it.
4216          *
4217          * @param int|Revision $old Old revision or rev ID (first before range)
4218          * @param int|Revision $new New revision or rev ID (first after range)
4219          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4220          * @return int Number of revisions between these revisions.
4221          */
4222         public function countRevisionsBetween( $old, $new, $max = null ) {
4223                 if ( !( $old instanceof Revision ) ) {
4224                         $old = Revision::newFromTitle( $this, (int)$old );
4225                 }
4226                 if ( !( $new instanceof Revision ) ) {
4227                         $new = Revision::newFromTitle( $this, (int)$new );
4228                 }
4229                 if ( !$old || !$new ) {
4230                         return 0; // nothing to compare
4231                 }
4232                 $dbr = wfGetDB( DB_REPLICA );
4233                 $conds = [
4234                         'rev_page' => $this->getArticleID(),
4235                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4236                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4237                 ];
4238                 if ( $max !== null ) {
4239                         return $dbr->selectRowCount( 'revision', '1',
4240                                 $conds,
4241                                 __METHOD__,
4242                                 [ 'LIMIT' => $max + 1 ] // extra to detect truncation
4243                         );
4244                 } else {
4245                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4246                 }
4247         }
4248
4249         /**
4250          * Get the authors between the given revisions or revision IDs.
4251          * Used for diffs and other things that really need it.
4252          *
4253          * @since 1.23
4254          *
4255          * @param int|Revision $old Old revision or rev ID (first before range by default)
4256          * @param int|Revision $new New revision or rev ID (first after range by default)
4257          * @param int $limit Maximum number of authors
4258          * @param string|array $options (Optional): Single option, or an array of options:
4259          *     'include_old' Include $old in the range; $new is excluded.
4260          *     'include_new' Include $new in the range; $old is excluded.
4261          *     'include_both' Include both $old and $new in the range.
4262          *     Unknown option values are ignored.
4263          * @return array|null Names of revision authors in the range; null if not both revisions exist
4264          */
4265         public function getAuthorsBetween( $old, $new, $limit, $options = [] ) {
4266                 if ( !( $old instanceof Revision ) ) {
4267                         $old = Revision::newFromTitle( $this, (int)$old );
4268                 }
4269                 if ( !( $new instanceof Revision ) ) {
4270                         $new = Revision::newFromTitle( $this, (int)$new );
4271                 }
4272                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4273                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4274                 // in the sanity check below?
4275                 if ( !$old || !$new ) {
4276                         return null; // nothing to compare
4277                 }
4278                 $authors = [];
4279                 $old_cmp = '>';
4280                 $new_cmp = '<';
4281                 $options = (array)$options;
4282                 if ( in_array( 'include_old', $options ) ) {
4283                         $old_cmp = '>=';
4284                 }
4285                 if ( in_array( 'include_new', $options ) ) {
4286                         $new_cmp = '<=';
4287                 }
4288                 if ( in_array( 'include_both', $options ) ) {
4289                         $old_cmp = '>=';
4290                         $new_cmp = '<=';
4291                 }
4292                 // No DB query needed if $old and $new are the same or successive revisions:
4293                 if ( $old->getId() === $new->getId() ) {
4294                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4295                                 [] :
4296                                 [ $old->getUserText( Revision::RAW ) ];
4297                 } elseif ( $old->getId() === $new->getParentId() ) {
4298                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4299                                 $authors[] = $old->getUserText( Revision::RAW );
4300                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4301                                         $authors[] = $new->getUserText( Revision::RAW );
4302                                 }
4303                         } elseif ( $old_cmp === '>=' ) {
4304                                 $authors[] = $old->getUserText( Revision::RAW );
4305                         } elseif ( $new_cmp === '<=' ) {
4306                                 $authors[] = $new->getUserText( Revision::RAW );
4307                         }
4308                         return $authors;
4309                 }
4310                 $dbr = wfGetDB( DB_REPLICA );
4311                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4312                         [
4313                                 'rev_page' => $this->getArticleID(),
4314                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4315                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4316                         ], __METHOD__,
4317                         [ 'LIMIT' => $limit + 1 ] // add one so caller knows it was truncated
4318                 );
4319                 foreach ( $res as $row ) {
4320                         $authors[] = $row->rev_user_text;
4321                 }
4322                 return $authors;
4323         }
4324
4325         /**
4326          * Get the number of authors between the given revisions or revision IDs.
4327          * Used for diffs and other things that really need it.
4328          *
4329          * @param int|Revision $old Old revision or rev ID (first before range by default)
4330          * @param int|Revision $new New revision or rev ID (first after range by default)
4331          * @param int $limit Maximum number of authors
4332          * @param string|array $options (Optional): Single option, or an array of options:
4333          *     'include_old' Include $old in the range; $new is excluded.
4334          *     'include_new' Include $new in the range; $old is excluded.
4335          *     'include_both' Include both $old and $new in the range.
4336          *     Unknown option values are ignored.
4337          * @return int Number of revision authors in the range; zero if not both revisions exist
4338          */
4339         public function countAuthorsBetween( $old, $new, $limit, $options = [] ) {
4340                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4341                 return $authors ? count( $authors ) : 0;
4342         }
4343
4344         /**
4345          * Compare with another title.
4346          *
4347          * @param Title $title
4348          * @return bool
4349          */
4350         public function equals( Title $title ) {
4351                 // Note: === is necessary for proper matching of number-like titles.
4352                 return $this->getInterwiki() === $title->getInterwiki()
4353                         && $this->getNamespace() == $title->getNamespace()
4354                         && $this->getDBkey() === $title->getDBkey();
4355         }
4356
4357         /**
4358          * Check if this title is a subpage of another title
4359          *
4360          * @param Title $title
4361          * @return bool
4362          */
4363         public function isSubpageOf( Title $title ) {
4364                 return $this->getInterwiki() === $title->getInterwiki()
4365                         && $this->getNamespace() == $title->getNamespace()
4366                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4367         }
4368
4369         /**
4370          * Check if page exists.  For historical reasons, this function simply
4371          * checks for the existence of the title in the page table, and will
4372          * thus return false for interwiki links, special pages and the like.
4373          * If you want to know if a title can be meaningfully viewed, you should
4374          * probably call the isKnown() method instead.
4375          *
4376          * @param int $flags An optional bit field; may be Title::GAID_FOR_UPDATE to check
4377          *   from master/for update
4378          * @return bool
4379          */
4380         public function exists( $flags = 0 ) {
4381                 $exists = $this->getArticleID( $flags ) != 0;
4382                 Hooks::run( 'TitleExists', [ $this, &$exists ] );
4383                 return $exists;
4384         }
4385
4386         /**
4387          * Should links to this title be shown as potentially viewable (i.e. as
4388          * "bluelinks"), even if there's no record by this title in the page
4389          * table?
4390          *
4391          * This function is semi-deprecated for public use, as well as somewhat
4392          * misleadingly named.  You probably just want to call isKnown(), which
4393          * calls this function internally.
4394          *
4395          * (ISSUE: Most of these checks are cheap, but the file existence check
4396          * can potentially be quite expensive.  Including it here fixes a lot of
4397          * existing code, but we might want to add an optional parameter to skip
4398          * it and any other expensive checks.)
4399          *
4400          * @return bool
4401          */
4402         public function isAlwaysKnown() {
4403                 $isKnown = null;
4404
4405                 /**
4406                  * Allows overriding default behavior for determining if a page exists.
4407                  * If $isKnown is kept as null, regular checks happen. If it's
4408                  * a boolean, this value is returned by the isKnown method.
4409                  *
4410                  * @since 1.20
4411                  *
4412                  * @param Title $title
4413                  * @param bool|null $isKnown
4414                  */
4415                 Hooks::run( 'TitleIsAlwaysKnown', [ $this, &$isKnown ] );
4416
4417                 if ( !is_null( $isKnown ) ) {
4418                         return $isKnown;
4419                 }
4420
4421                 if ( $this->isExternal() ) {
4422                         return true;  // any interwiki link might be viewable, for all we know
4423                 }
4424
4425                 switch ( $this->mNamespace ) {
4426                         case NS_MEDIA:
4427                         case NS_FILE:
4428                                 // file exists, possibly in a foreign repo
4429                                 return (bool)wfFindFile( $this );
4430                         case NS_SPECIAL:
4431                                 // valid special page
4432                                 return SpecialPageFactory::exists( $this->getDBkey() );
4433                         case NS_MAIN:
4434                                 // selflink, possibly with fragment
4435                                 return $this->mDbkeyform == '';
4436                         case NS_MEDIAWIKI:
4437                                 // known system message
4438                                 return $this->hasSourceText() !== false;
4439                         default:
4440                                 return false;
4441                 }
4442         }
4443
4444         /**
4445          * Does this title refer to a page that can (or might) be meaningfully
4446          * viewed?  In particular, this function may be used to determine if
4447          * links to the title should be rendered as "bluelinks" (as opposed to
4448          * "redlinks" to non-existent pages).
4449          * Adding something else to this function will cause inconsistency
4450          * since LinkHolderArray calls isAlwaysKnown() and does its own
4451          * page existence check.
4452          *
4453          * @return bool
4454          */
4455         public function isKnown() {
4456                 return $this->isAlwaysKnown() || $this->exists();
4457         }
4458
4459         /**
4460          * Does this page have source text?
4461          *
4462          * @return bool
4463          */
4464         public function hasSourceText() {
4465                 if ( $this->exists() ) {
4466                         return true;
4467                 }
4468
4469                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4470                         // If the page doesn't exist but is a known system message, default
4471                         // message content will be displayed, same for language subpages-
4472                         // Use always content language to avoid loading hundreds of languages
4473                         // to get the link color.
4474                         global $wgContLang;
4475                         list( $name, ) = MessageCache::singleton()->figureMessage(
4476                                 $wgContLang->lcfirst( $this->getText() )
4477                         );
4478                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4479                         return $message->exists();
4480                 }
4481
4482                 return false;
4483         }
4484
4485         /**
4486          * Get the default message text or false if the message doesn't exist
4487          *
4488          * @return string|bool
4489          */
4490         public function getDefaultMessageText() {
4491                 global $wgContLang;
4492
4493                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4494                         return false;
4495                 }
4496
4497                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4498                         $wgContLang->lcfirst( $this->getText() )
4499                 );
4500                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4501
4502                 if ( $message->exists() ) {
4503                         return $message->plain();
4504                 } else {
4505                         return false;
4506                 }
4507         }
4508
4509         /**
4510          * Updates page_touched for this page; called from LinksUpdate.php
4511          *
4512          * @param string $purgeTime [optional] TS_MW timestamp
4513          * @return bool True if the update succeeded
4514          */
4515         public function invalidateCache( $purgeTime = null ) {
4516                 if ( wfReadOnly() ) {
4517                         return false;
4518                 } elseif ( $this->mArticleID === 0 ) {
4519                         return true; // avoid gap locking if we know it's not there
4520                 }
4521
4522                 $dbw = wfGetDB( DB_MASTER );
4523                 $dbw->onTransactionPreCommitOrIdle( function () {
4524                         ResourceLoaderWikiModule::invalidateModuleCache( $this, null, null, wfWikiID() );
4525                 } );
4526
4527                 $conds = $this->pageCond();
4528                 DeferredUpdates::addUpdate(
4529                         new AutoCommitUpdate(
4530                                 $dbw,
4531                                 __METHOD__,
4532                                 function ( IDatabase $dbw, $fname ) use ( $conds, $purgeTime ) {
4533                                         $dbTimestamp = $dbw->timestamp( $purgeTime ?: time() );
4534                                         $dbw->update(
4535                                                 'page',
4536                                                 [ 'page_touched' => $dbTimestamp ],
4537                                                 $conds + [ 'page_touched < ' . $dbw->addQuotes( $dbTimestamp ) ],
4538                                                 $fname
4539                                         );
4540                                         MediaWikiServices::getInstance()->getLinkCache()->invalidateTitle( $this );
4541                                 }
4542                         ),
4543                         DeferredUpdates::PRESEND
4544                 );
4545
4546                 return true;
4547         }
4548
4549         /**
4550          * Update page_touched timestamps and send CDN purge messages for
4551          * pages linking to this title. May be sent to the job queue depending
4552          * on the number of links. Typically called on create and delete.
4553          */
4554         public function touchLinks() {
4555                 DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'pagelinks' ) );
4556                 if ( $this->getNamespace() == NS_CATEGORY ) {
4557                         DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'categorylinks' ) );
4558                 }
4559         }
4560
4561         /**
4562          * Get the last touched timestamp
4563          *
4564          * @param IDatabase $db Optional db
4565          * @return string|false Last-touched timestamp
4566          */
4567         public function getTouched( $db = null ) {
4568                 if ( $db === null ) {
4569                         $db = wfGetDB( DB_REPLICA );
4570                 }
4571                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4572                 return $touched;
4573         }
4574
4575         /**
4576          * Get the timestamp when this page was updated since the user last saw it.
4577          *
4578          * @param User $user
4579          * @return string|null
4580          */
4581         public function getNotificationTimestamp( $user = null ) {
4582                 global $wgUser;
4583
4584                 // Assume current user if none given
4585                 if ( !$user ) {
4586                         $user = $wgUser;
4587                 }
4588                 // Check cache first
4589                 $uid = $user->getId();
4590                 if ( !$uid ) {
4591                         return false;
4592                 }
4593                 // avoid isset here, as it'll return false for null entries
4594                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4595                         return $this->mNotificationTimestamp[$uid];
4596                 }
4597                 // Don't cache too much!
4598                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4599                         $this->mNotificationTimestamp = [];
4600                 }
4601
4602                 $store = MediaWikiServices::getInstance()->getWatchedItemStore();
4603                 $watchedItem = $store->getWatchedItem( $user, $this );
4604                 if ( $watchedItem ) {
4605                         $this->mNotificationTimestamp[$uid] = $watchedItem->getNotificationTimestamp();
4606                 } else {
4607                         $this->mNotificationTimestamp[$uid] = false;
4608                 }
4609
4610                 return $this->mNotificationTimestamp[$uid];
4611         }
4612
4613         /**
4614          * Generate strings used for xml 'id' names in monobook tabs
4615          *
4616          * @param string $prepend Defaults to 'nstab-'
4617          * @return string XML 'id' name
4618          */
4619         public function getNamespaceKey( $prepend = 'nstab-' ) {
4620                 global $wgContLang;
4621                 // Gets the subject namespace if this title
4622                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4623                 // Checks if canonical namespace name exists for namespace
4624                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4625                         // Uses canonical namespace name
4626                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4627                 } else {
4628                         // Uses text of namespace
4629                         $namespaceKey = $this->getSubjectNsText();
4630                 }
4631                 // Makes namespace key lowercase
4632                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4633                 // Uses main
4634                 if ( $namespaceKey == '' ) {
4635                         $namespaceKey = 'main';
4636                 }
4637                 // Changes file to image for backwards compatibility
4638                 if ( $namespaceKey == 'file' ) {
4639                         $namespaceKey = 'image';
4640                 }
4641                 return $prepend . $namespaceKey;
4642         }
4643
4644         /**
4645          * Get all extant redirects to this Title
4646          *
4647          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4648          * @return Title[] Array of Title redirects to this title
4649          */
4650         public function getRedirectsHere( $ns = null ) {
4651                 $redirs = [];
4652
4653                 $dbr = wfGetDB( DB_REPLICA );
4654                 $where = [
4655                         'rd_namespace' => $this->getNamespace(),
4656                         'rd_title' => $this->getDBkey(),
4657                         'rd_from = page_id'
4658                 ];
4659                 if ( $this->isExternal() ) {
4660                         $where['rd_interwiki'] = $this->getInterwiki();
4661                 } else {
4662                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4663                 }
4664                 if ( !is_null( $ns ) ) {
4665                         $where['page_namespace'] = $ns;
4666                 }
4667
4668                 $res = $dbr->select(
4669                         [ 'redirect', 'page' ],
4670                         [ 'page_namespace', 'page_title' ],
4671                         $where,
4672                         __METHOD__
4673                 );
4674
4675                 foreach ( $res as $row ) {
4676                         $redirs[] = self::newFromRow( $row );
4677                 }
4678                 return $redirs;
4679         }
4680
4681         /**
4682          * Check if this Title is a valid redirect target
4683          *
4684          * @return bool
4685          */
4686         public function isValidRedirectTarget() {
4687                 global $wgInvalidRedirectTargets;
4688
4689                 if ( $this->isSpecialPage() ) {
4690                         // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4691                         if ( $this->isSpecial( 'Userlogout' ) ) {
4692                                 return false;
4693                         }
4694
4695                         foreach ( $wgInvalidRedirectTargets as $target ) {
4696                                 if ( $this->isSpecial( $target ) ) {
4697                                         return false;
4698                                 }
4699                         }
4700                 }
4701
4702                 return true;
4703         }
4704
4705         /**
4706          * Get a backlink cache object
4707          *
4708          * @return BacklinkCache
4709          */
4710         public function getBacklinkCache() {
4711                 return BacklinkCache::get( $this );
4712         }
4713
4714         /**
4715          * Whether the magic words __INDEX__ and __NOINDEX__ function for this page.
4716          *
4717          * @return bool
4718          */
4719         public function canUseNoindex() {
4720                 global $wgExemptFromUserRobotsControl;
4721
4722                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4723                         ? MWNamespace::getContentNamespaces()
4724                         : $wgExemptFromUserRobotsControl;
4725
4726                 return !in_array( $this->mNamespace, $bannedNamespaces );
4727         }
4728
4729         /**
4730          * Returns the raw sort key to be used for categories, with the specified
4731          * prefix.  This will be fed to Collation::getSortKey() to get a
4732          * binary sortkey that can be used for actual sorting.
4733          *
4734          * @param string $prefix The prefix to be used, specified using
4735          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4736          *   prefix.
4737          * @return string
4738          */
4739         public function getCategorySortkey( $prefix = '' ) {
4740                 $unprefixed = $this->getText();
4741
4742                 // Anything that uses this hook should only depend
4743                 // on the Title object passed in, and should probably
4744                 // tell the users to run updateCollations.php --force
4745                 // in order to re-sort existing category relations.
4746                 Hooks::run( 'GetDefaultSortkey', [ $this, &$unprefixed ] );
4747                 if ( $prefix !== '' ) {
4748                         # Separate with a line feed, so the unprefixed part is only used as
4749                         # a tiebreaker when two pages have the exact same prefix.
4750                         # In UCA, tab is the only character that can sort above LF
4751                         # so we strip both of them from the original prefix.
4752                         $prefix = strtr( $prefix, "\n\t", '  ' );
4753                         return "$prefix\n$unprefixed";
4754                 }
4755                 return $unprefixed;
4756         }
4757
4758         /**
4759          * Returns the page language code saved in the database, if $wgPageLanguageUseDB is set
4760          * to true in LocalSettings.php, otherwise returns false. If there is no language saved in
4761          * the db, it will return NULL.
4762          *
4763          * @return string|null|bool
4764          */
4765         private function getDbPageLanguageCode() {
4766                 global $wgPageLanguageUseDB;
4767
4768                 // check, if the page language could be saved in the database, and if so and
4769                 // the value is not requested already, lookup the page language using LinkCache
4770                 if ( $wgPageLanguageUseDB && $this->mDbPageLanguage === false ) {
4771                         $linkCache = LinkCache::singleton();
4772                         $linkCache->addLinkObj( $this );
4773                         $this->mDbPageLanguage = $linkCache->getGoodLinkFieldObj( $this, 'lang' );
4774                 }
4775
4776                 return $this->mDbPageLanguage;
4777         }
4778
4779         /**
4780          * Get the language in which the content of this page is written in
4781          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4782          * e.g. $wgLang (such as special pages, which are in the user language).
4783          *
4784          * @since 1.18
4785          * @return Language
4786          */
4787         public function getPageLanguage() {
4788                 global $wgLang, $wgLanguageCode;
4789                 if ( $this->isSpecialPage() ) {
4790                         // special pages are in the user language
4791                         return $wgLang;
4792                 }
4793
4794                 // Checking if DB language is set
4795                 $dbPageLanguage = $this->getDbPageLanguageCode();
4796                 if ( $dbPageLanguage ) {
4797                         return wfGetLangObj( $dbPageLanguage );
4798                 }
4799
4800                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4801                         // Note that this may depend on user settings, so the cache should
4802                         // be only per-request.
4803                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4804                         // content to determine the page language!
4805                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4806                         // tests.
4807                         $contentHandler = ContentHandler::getForTitle( $this );
4808                         $langObj = $contentHandler->getPageLanguage( $this );
4809                         $this->mPageLanguage = [ $langObj->getCode(), $wgLanguageCode ];
4810                 } else {
4811                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4812                 }
4813
4814                 return $langObj;
4815         }
4816
4817         /**
4818          * Get the language in which the content of this page is written when
4819          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4820          * e.g. $wgLang (such as special pages, which are in the user language).
4821          *
4822          * @since 1.20
4823          * @return Language
4824          */
4825         public function getPageViewLanguage() {
4826                 global $wgLang;
4827
4828                 if ( $this->isSpecialPage() ) {
4829                         // If the user chooses a variant, the content is actually
4830                         // in a language whose code is the variant code.
4831                         $variant = $wgLang->getPreferredVariant();
4832                         if ( $wgLang->getCode() !== $variant ) {
4833                                 return Language::factory( $variant );
4834                         }
4835
4836                         return $wgLang;
4837                 }
4838
4839                 // Checking if DB language is set
4840                 $dbPageLanguage = $this->getDbPageLanguageCode();
4841                 if ( $dbPageLanguage ) {
4842                         $pageLang = wfGetLangObj( $dbPageLanguage );
4843                         $variant = $pageLang->getPreferredVariant();
4844                         if ( $pageLang->getCode() !== $variant ) {
4845                                 $pageLang = Language::factory( $variant );
4846                         }
4847
4848                         return $pageLang;
4849                 }
4850
4851                 // @note Can't be cached persistently, depends on user settings.
4852                 // @note ContentHandler::getPageViewLanguage() may need to load the
4853                 //   content to determine the page language!
4854                 $contentHandler = ContentHandler::getForTitle( $this );
4855                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4856                 return $pageLang;
4857         }
4858
4859         /**
4860          * Get a list of rendered edit notices for this page.
4861          *
4862          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4863          * they will already be wrapped in paragraphs.
4864          *
4865          * @since 1.21
4866          * @param int $oldid Revision ID that's being edited
4867          * @return array
4868          */
4869         public function getEditNotices( $oldid = 0 ) {
4870                 $notices = [];
4871
4872                 // Optional notice for the entire namespace
4873                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4874                 $msg = wfMessage( $editnotice_ns );
4875                 if ( $msg->exists() ) {
4876                         $html = $msg->parseAsBlock();
4877                         // Edit notices may have complex logic, but output nothing (T91715)
4878                         if ( trim( $html ) !== '' ) {
4879                                 $notices[$editnotice_ns] = Html::rawElement(
4880                                         'div',
4881                                         [ 'class' => [
4882                                                 'mw-editnotice',
4883                                                 'mw-editnotice-namespace',
4884                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4885                                         ] ],
4886                                         $html
4887                                 );
4888                         }
4889                 }
4890
4891                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4892                         // Optional notice for page itself and any parent page
4893                         $parts = explode( '/', $this->getDBkey() );
4894                         $editnotice_base = $editnotice_ns;
4895                         while ( count( $parts ) > 0 ) {
4896                                 $editnotice_base .= '-' . array_shift( $parts );
4897                                 $msg = wfMessage( $editnotice_base );
4898                                 if ( $msg->exists() ) {
4899                                         $html = $msg->parseAsBlock();
4900                                         if ( trim( $html ) !== '' ) {
4901                                                 $notices[$editnotice_base] = Html::rawElement(
4902                                                         'div',
4903                                                         [ 'class' => [
4904                                                                 'mw-editnotice',
4905                                                                 'mw-editnotice-base',
4906                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4907                                                         ] ],
4908                                                         $html
4909                                                 );
4910                                         }
4911                                 }
4912                         }
4913                 } else {
4914                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4915                         $editnoticeText = $editnotice_ns . '-' . strtr( $this->getDBkey(), '/', '-' );
4916                         $msg = wfMessage( $editnoticeText );
4917                         if ( $msg->exists() ) {
4918                                 $html = $msg->parseAsBlock();
4919                                 if ( trim( $html ) !== '' ) {
4920                                         $notices[$editnoticeText] = Html::rawElement(
4921                                                 'div',
4922                                                 [ 'class' => [
4923                                                         'mw-editnotice',
4924                                                         'mw-editnotice-page',
4925                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4926                                                 ] ],
4927                                                 $html
4928                                         );
4929                                 }
4930                         }
4931                 }
4932
4933                 Hooks::run( 'TitleGetEditNotices', [ $this, $oldid, &$notices ] );
4934                 return $notices;
4935         }
4936
4937         /**
4938          * @return array
4939          */
4940         public function __sleep() {
4941                 return [
4942                         'mNamespace',
4943                         'mDbkeyform',
4944                         'mFragment',
4945                         'mInterwiki',
4946                         'mLocalInterwiki',
4947                         'mUserCaseDBKey',
4948                         'mDefaultNamespace',
4949                 ];
4950         }
4951
4952         public function __wakeup() {
4953                 $this->mArticleID = ( $this->mNamespace >= 0 ) ? -1 : 0;
4954                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
4955                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
4956         }
4957
4958 }