includes/Title.php

   1 <?php
   2 /**
   3  * Representation of a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24 use MediaWiki\Linker\LinkTarget;
  25 use MediaWiki\Interwiki\InterwikiLookup;
  26 use MediaWiki\MediaWikiServices;
  27
  28 /**
  29  * Represents a title within MediaWiki.
  30  * Optionally may contain an interwiki designation or namespace.
  31  * @note This class can fetch various kinds of data from the database;
  32  *       however, it does so inefficiently.
  33  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  34  *       and does not rely on global state or the database.
  35  */
  36 class Title implements LinkTarget {
  37         /** @var HashBagOStuff */
  38         static private $titleCache = null;
  39
  40         /**
  41          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  42          * commonly used titles. On a batch operation this can become a memory leak
  43          * if not bounded. After hitting this many titles reset the cache.
  44          */
  45         const CACHE_MAX = 1000;
  46
  47         /**
  48          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  49          * to use the master DB
  50          */
  51         const GAID_FOR_UPDATE = 1;
  52
  53         /**
  54          * @name Private member variables
  55          * Please use the accessor functions instead.
  56          * @private
  57          */
  58         // @{
  59
  60         /** @var string Text form (spaces not underscores) of the main part */
  61         public $mTextform = '';
  62
  63         /** @var string URL-encoded form of the main part */
  64         public $mUrlform = '';
  65
  66         /** @var string Main part with underscores */
  67         public $mDbkeyform = '';
  68
  69         /** @var string Database key with the initial letter in the case specified by the user */
  70         protected $mUserCaseDBKey;
  71
  72         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  73         public $mNamespace = NS_MAIN;
  74
  75         /** @var string Interwiki prefix */
  76         public $mInterwiki = '';
  77
  78         /** @var bool Was this Title created from a string with a local interwiki prefix? */
  79         private $mLocalInterwiki = false;
  80
  81         /** @var string Title fragment (i.e. the bit after the #) */
  82         public $mFragment = '';
  83
  84         /** @var int Article ID, fetched from the link cache on demand */
  85         public $mArticleID = -1;
  86
  87         /** @var bool|int ID of most recent revision */
  88         protected $mLatestID = false;
  89
  90         /**
  91          * @var bool|string ID of the page's content model, i.e. one of the
  92          *   CONTENT_MODEL_XXX constants
  93          */
  94         public $mContentModel = false;
  95
  96         /** @var int Estimated number of revisions; null of not loaded */
  97         private $mEstimateRevisions;
  98
  99         /** @var array Array of groups allowed to edit this article */
 100         public $mRestrictions = [];
 101
 102         /** @var string|bool */
 103         protected $mOldRestrictions = false;
 104
 105         /** @var bool Cascade restrictions on this page to included templates and images? */
 106         public $mCascadeRestriction;
 107
 108         /** Caching the results of getCascadeProtectionSources */
 109         public $mCascadingRestrictions;
 110
 111         /** @var array When do the restrictions on this page expire? */
 112         protected $mRestrictionsExpiry = [];
 113
 114         /** @var bool Are cascading restrictions in effect on this page? */
 115         protected $mHasCascadingRestrictions;
 116
 117         /** @var array Where are the cascading restrictions coming from on this page? */
 118         public $mCascadeSources;
 119
 120         /** @var bool Boolean for initialisation on demand */
 121         public $mRestrictionsLoaded = false;
 122
 123         /** @var string Text form including namespace/interwiki, initialised on demand */
 124         protected $mPrefixedText = null;
 125
 126         /** @var mixed Cached value for getTitleProtection (create protection) */
 127         public $mTitleProtection;
 128
 129         /**
 130          * @var int Namespace index when there is no namespace. Don't change the
 131          *   following default, NS_MAIN is hardcoded in several places. See bug 696.
 132          *   Zero except in {{transclusion}} tags.
 133          */
 134         public $mDefaultNamespace = NS_MAIN;
 135
 136         /** @var int The page length, 0 for special pages */
 137         protected $mLength = -1;
 138
 139         /** @var null Is the article at this title a redirect? */
 140         public $mRedirect = null;
 141
 142         /** @var array Associative array of user ID -> timestamp/false */
 143         private $mNotificationTimestamp = [];
 144
 145         /** @var bool Whether a page has any subpages */
 146         private $mHasSubpages;
 147
 148         /** @var bool The (string) language code of the page's language and content code. */
 149         private $mPageLanguage = false;
 150
 151         /** @var string|bool|null The page language code from the database, null if not saved in
 152          * the database or false if not loaded, yet. */
 153         private $mDbPageLanguage = false;
 154
 155         /** @var TitleValue A corresponding TitleValue object */
 156         private $mTitleValue = null;
 157
 158         /** @var bool Would deleting this page be a big deletion? */
 159         private $mIsBigDeletion = null;
 160         // @}
 161
 162         /**
 163          * B/C kludge: provide a TitleParser for use by Title.
 164          * Ideally, Title would have no methods that need this.
 165          * Avoid usage of this singleton by using TitleValue
 166          * and the associated services when possible.
 167          *
 168          * @return TitleFormatter
 169          */
 170         private static function getTitleFormatter() {
 171                 return MediaWikiServices::getInstance()->getTitleFormatter();
 172         }
 173
 174         /**
 175          * B/C kludge: provide an InterwikiLookup for use by Title.
 176          * Ideally, Title would have no methods that need this.
 177          * Avoid usage of this singleton by using TitleValue
 178          * and the associated services when possible.
 179          *
 180          * @return InterwikiLookup
 181          */
 182         private static function getInterwikiLookup() {
 183                 return MediaWikiServices::getInstance()->getInterwikiLookup();
 184         }
 185
 186         /**
 187          * @access protected
 188          */
 189         function __construct() {
 190         }
 191
 192         /**
 193          * Create a new Title from a prefixed DB key
 194          *
 195          * @param string $key The database key, which has underscores
 196          *      instead of spaces, possibly including namespace and
 197          *      interwiki prefixes
 198          * @return Title|null Title, or null on an error
 199          */
 200         public static function newFromDBkey( $key ) {
 201                 $t = new Title();
 202                 $t->mDbkeyform = $key;
 203
 204                 try {
 205                         $t->secureAndSplit();
 206                         return $t;
 207                 } catch ( MalformedTitleException $ex ) {
 208                         return null;
 209                 }
 210         }
 211
 212         /**
 213          * Create a new Title from a TitleValue
 214          *
 215          * @param TitleValue $titleValue Assumed to be safe.
 216          *
 217          * @return Title
 218          */
 219         public static function newFromTitleValue( TitleValue $titleValue ) {
 220                 return self::newFromLinkTarget( $titleValue );
 221         }
 222
 223         /**
 224          * Create a new Title from a LinkTarget
 225          *
 226          * @param LinkTarget $linkTarget Assumed to be safe.
 227          *
 228          * @return Title
 229          */
 230         public static function newFromLinkTarget( LinkTarget $linkTarget ) {
 231                 if ( $linkTarget instanceof Title ) {
 232                         // Special case if it's already a Title object
 233                         return $linkTarget;
 234                 }
 235                 return self::makeTitle(
 236                         $linkTarget->getNamespace(),
 237                         $linkTarget->getText(),
 238                         $linkTarget->getFragment(),
 239                         $linkTarget->getInterwiki()
 240                 );
 241         }
 242
 243         /**
 244          * Create a new Title from text, such as what one would find in a link. De-
 245          * codes any HTML entities in the text.
 246          *
 247          * @param string|int|null $text The link text; spaces, prefixes, and an
 248          *   initial ':' indicating the main namespace are accepted.
 249          * @param int $defaultNamespace The namespace to use if none is specified
 250          *   by a prefix.  If you want to force a specific namespace even if
 251          *   $text might begin with a namespace prefix, use makeTitle() or
 252          *   makeTitleSafe().
 253          * @throws InvalidArgumentException
 254          * @return Title|null Title or null on an error.
 255          */
 256         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 257                 // DWIM: Integers can be passed in here when page titles are used as array keys.
 258                 if ( $text !== null && !is_string( $text ) && !is_int( $text ) ) {
 259                         throw new InvalidArgumentException( '$text must be a string.' );
 260                 }
 261                 if ( $text === null ) {
 262                         return null;
 263                 }
 264
 265                 try {
 266                         return Title::newFromTextThrow( strval( $text ), $defaultNamespace );
 267                 } catch ( MalformedTitleException $ex ) {
 268                         return null;
 269                 }
 270         }
 271
 272         /**
 273          * Like Title::newFromText(), but throws MalformedTitleException when the title is invalid,
 274          * rather than returning null.
 275          *
 276          * The exception subclasses encode detailed information about why the title is invalid.
 277          *
 278          * @see Title::newFromText
 279          *
 280          * @since 1.25
 281          * @param string $text Title text to check
 282          * @param int $defaultNamespace
 283          * @throws MalformedTitleException If the title is invalid
 284          * @return Title
 285          */
 286         public static function newFromTextThrow( $text, $defaultNamespace = NS_MAIN ) {
 287                 if ( is_object( $text ) ) {
 288                         throw new MWException( '$text must be a string, given an object' );
 289                 }
 290
 291                 $titleCache = self::getTitleCache();
 292
 293                 // Wiki pages often contain multiple links to the same page.
 294                 // Title normalization and parsing can become expensive on pages with many
 295                 // links, so we can save a little time by caching them.
 296                 // In theory these are value objects and won't get changed...
 297                 if ( $defaultNamespace == NS_MAIN ) {
 298                         $t = $titleCache->get( $text );
 299                         if ( $t ) {
 300                                 return $t;
 301                         }
 302                 }
 303
 304                 // Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 305                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 306
 307                 $t = new Title();
 308                 $t->mDbkeyform = strtr( $filteredText, ' ', '_' );
 309                 $t->mDefaultNamespace = intval( $defaultNamespace );
 310
 311                 $t->secureAndSplit();
 312                 if ( $defaultNamespace == NS_MAIN ) {
 313                         $titleCache->set( $text, $t );
 314                 }
 315                 return $t;
 316         }
 317
 318         /**
 319          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 320          *
 321          * Example of wrong and broken code:
 322          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 323          *
 324          * Example of right code:
 325          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 326          *
 327          * Create a new Title from URL-encoded text. Ensures that
 328          * the given title's length does not exceed the maximum.
 329          *
 330          * @param string $url The title, as might be taken from a URL
 331          * @return Title|null The new object, or null on an error
 332          */
 333         public static function newFromURL( $url ) {
 334                 $t = new Title();
 335
 336                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 337                 # but some URLs used it as a space replacement and they still come
 338                 # from some external search tools.
 339                 if ( strpos( self::legalChars(), '+' ) === false ) {
 340                         $url = strtr( $url, '+', ' ' );
 341                 }
 342
 343                 $t->mDbkeyform = strtr( $url, ' ', '_' );
 344
 345                 try {
 346                         $t->secureAndSplit();
 347                         return $t;
 348                 } catch ( MalformedTitleException $ex ) {
 349                         return null;
 350                 }
 351         }
 352
 353         /**
 354          * @return HashBagOStuff
 355          */
 356         private static function getTitleCache() {
 357                 if ( self::$titleCache == null ) {
 358                         self::$titleCache = new HashBagOStuff( [ 'maxKeys' => self::CACHE_MAX ] );
 359                 }
 360                 return self::$titleCache;
 361         }
 362
 363         /**
 364          * Returns a list of fields that are to be selected for initializing Title
 365          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 366          * whether to include page_content_model.
 367          *
 368          * @return array
 369          */
 370         protected static function getSelectFields() {
 371                 global $wgContentHandlerUseDB, $wgPageLanguageUseDB;
 372
 373                 $fields = [
 374                         'page_namespace', 'page_title', 'page_id',
 375                         'page_len', 'page_is_redirect', 'page_latest',
 376                 ];
 377
 378                 if ( $wgContentHandlerUseDB ) {
 379                         $fields[] = 'page_content_model';
 380                 }
 381
 382                 if ( $wgPageLanguageUseDB ) {
 383                         $fields[] = 'page_lang';
 384                 }
 385
 386                 return $fields;
 387         }
 388
 389         /**
 390          * Create a new Title from an article ID
 391          *
 392          * @param int $id The page_id corresponding to the Title to create
 393          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 394          * @return Title|null The new object, or null on an error
 395          */
 396         public static function newFromID( $id, $flags = 0 ) {
 397                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_REPLICA );
 398                 $row = $db->selectRow(
 399                         'page',
 400                         self::getSelectFields(),
 401                         [ 'page_id' => $id ],
 402                         __METHOD__
 403                 );
 404                 if ( $row !== false ) {
 405                         $title = Title::newFromRow( $row );
 406                 } else {
 407                         $title = null;
 408                 }
 409                 return $title;
 410         }
 411
 412         /**
 413          * Make an array of titles from an array of IDs
 414          *
 415          * @param int[] $ids Array of IDs
 416          * @return Title[] Array of Titles
 417          */
 418         public static function newFromIDs( $ids ) {
 419                 if ( !count( $ids ) ) {
 420                         return [];
 421                 }
 422                 $dbr = wfGetDB( DB_REPLICA );
 423
 424                 $res = $dbr->select(
 425                         'page',
 426                         self::getSelectFields(),
 427                         [ 'page_id' => $ids ],
 428                         __METHOD__
 429                 );
 430
 431                 $titles = [];
 432                 foreach ( $res as $row ) {
 433                         $titles[] = Title::newFromRow( $row );
 434                 }
 435                 return $titles;
 436         }
 437
 438         /**
 439          * Make a Title object from a DB row
 440          *
 441          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 442          * @return Title Corresponding Title
 443          */
 444         public static function newFromRow( $row ) {
 445                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 446                 $t->loadFromRow( $row );
 447                 return $t;
 448         }
 449
 450         /**
 451          * Load Title object fields from a DB row.
 452          * If false is given, the title will be treated as non-existing.
 453          *
 454          * @param stdClass|bool $row Database row
 455          */
 456         public function loadFromRow( $row ) {
 457                 if ( $row ) { // page found
 458                         if ( isset( $row->page_id ) ) {
 459                                 $this->mArticleID = (int)$row->page_id;
 460                         }
 461                         if ( isset( $row->page_len ) ) {
 462                                 $this->mLength = (int)$row->page_len;
 463                         }
 464                         if ( isset( $row->page_is_redirect ) ) {
 465                                 $this->mRedirect = (bool)$row->page_is_redirect;
 466                         }
 467                         if ( isset( $row->page_latest ) ) {
 468                                 $this->mLatestID = (int)$row->page_latest;
 469                         }
 470                         if ( isset( $row->page_content_model ) ) {
 471                                 $this->mContentModel = strval( $row->page_content_model );
 472                         } else {
 473                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 474                         }
 475                         if ( isset( $row->page_lang ) ) {
 476                                 $this->mDbPageLanguage = (string)$row->page_lang;
 477                         }
 478                         if ( isset( $row->page_restrictions ) ) {
 479                                 $this->mOldRestrictions = $row->page_restrictions;
 480                         }
 481                 } else { // page not found
 482                         $this->mArticleID = 0;
 483                         $this->mLength = 0;
 484                         $this->mRedirect = false;
 485                         $this->mLatestID = 0;
 486                         $this->mContentModel = false; # initialized lazily in getContentModel()
 487                 }
 488         }
 489
 490         /**
 491          * Create a new Title from a namespace index and a DB key.
 492          * It's assumed that $ns and $title are *valid*, for instance when
 493          * they came directly from the database or a special page name.
 494          * For convenience, spaces are converted to underscores so that
 495          * eg user_text fields can be used directly.
 496          *
 497          * @param int $ns The namespace of the article
 498          * @param string $title The unprefixed database key form
 499          * @param string $fragment The link fragment (after the "#")
 500          * @param string $interwiki The interwiki prefix
 501          * @return Title The new object
 502          */
 503         public static function makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 504                 $t = new Title();
 505                 $t->mInterwiki = $interwiki;
 506                 $t->mFragment = $fragment;
 507                 $t->mNamespace = $ns = intval( $ns );
 508                 $t->mDbkeyform = strtr( $title, ' ', '_' );
 509                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 510                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 511                 $t->mTextform = strtr( $title, '_', ' ' );
 512                 $t->mContentModel = false; # initialized lazily in getContentModel()
 513                 return $t;
 514         }
 515
 516         /**
 517          * Create a new Title from a namespace index and a DB key.
 518          * The parameters will be checked for validity, which is a bit slower
 519          * than makeTitle() but safer for user-provided data.
 520          *
 521          * @param int $ns The namespace of the article
 522          * @param string $title Database key form
 523          * @param string $fragment The link fragment (after the "#")
 524          * @param string $interwiki Interwiki prefix
 525          * @return Title|null The new object, or null on an error
 526          */
 527         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 528                 if ( !MWNamespace::exists( $ns ) ) {
 529                         return null;
 530                 }
 531
 532                 $t = new Title();
 533                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 534
 535                 try {
 536                         $t->secureAndSplit();
 537                         return $t;
 538                 } catch ( MalformedTitleException $ex ) {
 539                         return null;
 540                 }
 541         }
 542
 543         /**
 544          * Create a new Title for the Main Page
 545          *
 546          * @return Title The new object
 547          */
 548         public static function newMainPage() {
 549                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 550                 // Don't give fatal errors if the message is broken
 551                 if ( !$title ) {
 552                         $title = Title::newFromText( 'Main Page' );
 553                 }
 554                 return $title;
 555         }
 556
 557         /**
 558          * Get the prefixed DB key associated with an ID
 559          *
 560          * @param int $id The page_id of the article
 561          * @return Title|null An object representing the article, or null if no such article was found
 562          */
 563         public static function nameOf( $id ) {
 564                 $dbr = wfGetDB( DB_REPLICA );
 565
 566                 $s = $dbr->selectRow(
 567                         'page',
 568                         [ 'page_namespace', 'page_title' ],
 569                         [ 'page_id' => $id ],
 570                         __METHOD__
 571                 );
 572                 if ( $s === false ) {
 573                         return null;
 574                 }
 575
 576                 $n = self::makeName( $s->page_namespace, $s->page_title );
 577                 return $n;
 578         }
 579
 580         /**
 581          * Get a regex character class describing the legal characters in a link
 582          *
 583          * @return string The list of characters, not delimited
 584          */
 585         public static function legalChars() {
 586                 global $wgLegalTitleChars;
 587                 return $wgLegalTitleChars;
 588         }
 589
 590         /**
 591          * Returns a simple regex that will match on characters and sequences invalid in titles.
 592          * Note that this doesn't pick up many things that could be wrong with titles, but that
 593          * replacing this regex with something valid will make many titles valid.
 594          *
 595          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 596          *
 597          * @return string Regex string
 598          */
 599         static function getTitleInvalidRegex() {
 600                 wfDeprecated( __METHOD__, '1.25' );
 601                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 602         }
 603
 604         /**
 605          * Utility method for converting a character sequence from bytes to Unicode.
 606          *
 607          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 608          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 609          *
 610          * @param string $byteClass
 611          * @return string
 612          */
 613         public static function convertByteClassToUnicodeClass( $byteClass ) {
 614                 $length = strlen( $byteClass );
 615                 // Input token queue
 616                 $x0 = $x1 = $x2 = '';
 617                 // Decoded queue
 618                 $d0 = $d1 = $d2 = '';
 619                 // Decoded integer codepoints
 620                 $ord0 = $ord1 = $ord2 = 0;
 621                 // Re-encoded queue
 622                 $r0 = $r1 = $r2 = '';
 623                 // Output
 624                 $out = '';
 625                 // Flags
 626                 $allowUnicode = false;
 627                 for ( $pos = 0; $pos < $length; $pos++ ) {
 628                         // Shift the queues down
 629                         $x2 = $x1;
 630                         $x1 = $x0;
 631                         $d2 = $d1;
 632                         $d1 = $d0;
 633                         $ord2 = $ord1;
 634                         $ord1 = $ord0;
 635                         $r2 = $r1;
 636                         $r1 = $r0;
 637                         // Load the current input token and decoded values
 638                         $inChar = $byteClass[$pos];
 639                         if ( $inChar == '\\' ) {
 640                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 641                                         $x0 = $inChar . $m[0];
 642                                         $d0 = chr( hexdec( $m[1] ) );
 643                                         $pos += strlen( $m[0] );
 644                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 645                                         $x0 = $inChar . $m[0];
 646                                         $d0 = chr( octdec( $m[0] ) );
 647                                         $pos += strlen( $m[0] );
 648                                 } elseif ( $pos + 1 >= $length ) {
 649                                         $x0 = $d0 = '\\';
 650                                 } else {
 651                                         $d0 = $byteClass[$pos + 1];
 652                                         $x0 = $inChar . $d0;
 653                                         $pos += 1;
 654                                 }
 655                         } else {
 656                                 $x0 = $d0 = $inChar;
 657                         }
 658                         $ord0 = ord( $d0 );
 659                         // Load the current re-encoded value
 660                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 661                                 $r0 = sprintf( '\x%02x', $ord0 );
 662                         } elseif ( $ord0 >= 0x80 ) {
 663                                 // Allow unicode if a single high-bit character appears
 664                                 $r0 = sprintf( '\x%02x', $ord0 );
 665                                 $allowUnicode = true;
 666                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 667                                 $r0 = '\\' . $d0;
 668                         } else {
 669                                 $r0 = $d0;
 670                         }
 671                         // Do the output
 672                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 673                                 // Range
 674                                 if ( $ord2 > $ord0 ) {
 675                                         // Empty range
 676                                 } elseif ( $ord0 >= 0x80 ) {
 677                                         // Unicode range
 678                                         $allowUnicode = true;
 679                                         if ( $ord2 < 0x80 ) {
 680                                                 // Keep the non-unicode section of the range
 681                                                 $out .= "$r2-\\x7F";
 682                                         }
 683                                 } else {
 684                                         // Normal range
 685                                         $out .= "$r2-$r0";
 686                                 }
 687                                 // Reset state to the initial value
 688                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 689                         } elseif ( $ord2 < 0x80 ) {
 690                                 // ASCII character
 691                                 $out .= $r2;
 692                         }
 693                 }
 694                 if ( $ord1 < 0x80 ) {
 695                         $out .= $r1;
 696                 }
 697                 if ( $ord0 < 0x80 ) {
 698                         $out .= $r0;
 699                 }
 700                 if ( $allowUnicode ) {
 701                         $out .= '\u0080-\uFFFF';
 702                 }
 703                 return $out;
 704         }
 705
 706         /**
 707          * Make a prefixed DB key from a DB key and a namespace index
 708          *
 709          * @param int $ns Numerical representation of the namespace
 710          * @param string $title The DB key form the title
 711          * @param string $fragment The link fragment (after the "#")
 712          * @param string $interwiki The interwiki prefix
 713          * @param bool $canonicalNamespace If true, use the canonical name for
 714          *   $ns instead of the localized version.
 715          * @return string The prefixed form of the title
 716          */
 717         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 718                 $canonicalNamespace = false
 719         ) {
 720                 global $wgContLang;
 721
 722                 if ( $canonicalNamespace ) {
 723                         $namespace = MWNamespace::getCanonicalName( $ns );
 724                 } else {
 725                         $namespace = $wgContLang->getNsText( $ns );
 726                 }
 727                 $name = $namespace == '' ? $title : "$namespace:$title";
 728                 if ( strval( $interwiki ) != '' ) {
 729                         $name = "$interwiki:$name";
 730                 }
 731                 if ( strval( $fragment ) != '' ) {
 732                         $name .= '#' . $fragment;
 733                 }
 734                 return $name;
 735         }
 736
 737         /**
 738          * Escape a text fragment, say from a link, for a URL
 739          *
 740          * @param string $fragment Containing a URL or link fragment (after the "#")
 741          * @return string Escaped string
 742          */
 743         static function escapeFragmentForURL( $fragment ) {
 744                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 745                 # fragments appear not to work in IE (at least up to 7) or in at least
 746                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 747                 # to care if they aren't encoded.
 748                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 749         }
 750
 751         /**
 752          * Callback for usort() to do title sorts by (namespace, title)
 753          *
 754          * @param LinkTarget $a
 755          * @param LinkTarget $b
 756          *
 757          * @return int Result of string comparison, or namespace comparison
 758          */
 759         public static function compare( LinkTarget $a, LinkTarget $b ) {
 760                 if ( $a->getNamespace() == $b->getNamespace() ) {
 761                         return strcmp( $a->getText(), $b->getText() );
 762                 } else {
 763                         return $a->getNamespace() - $b->getNamespace();
 764                 }
 765         }
 766
 767         /**
 768          * Determine whether the object refers to a page within
 769          * this project (either this wiki or a wiki with a local
 770          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 771          *
 772          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 773          */
 774         public function isLocal() {
 775                 if ( $this->isExternal() ) {
 776                         $iw = self::getInterwikiLookup()->fetch( $this->mInterwiki );
 777                         if ( $iw ) {
 778                                 return $iw->isLocal();
 779                         }
 780                 }
 781                 return true;
 782         }
 783
 784         /**
 785          * Is this Title interwiki?
 786          *
 787          * @return bool
 788          */
 789         public function isExternal() {
 790                 return $this->mInterwiki !== '';
 791         }
 792
 793         /**
 794          * Get the interwiki prefix
 795          *
 796          * Use Title::isExternal to check if a interwiki is set
 797          *
 798          * @return string Interwiki prefix
 799          */
 800         public function getInterwiki() {
 801                 return $this->mInterwiki;
 802         }
 803
 804         /**
 805          * Was this a local interwiki link?
 806          *
 807          * @return bool
 808          */
 809         public function wasLocalInterwiki() {
 810                 return $this->mLocalInterwiki;
 811         }
 812
 813         /**
 814          * Determine whether the object refers to a page within
 815          * this project and is transcludable.
 816          *
 817          * @return bool True if this is transcludable
 818          */
 819         public function isTrans() {
 820                 if ( !$this->isExternal() ) {
 821                         return false;
 822                 }
 823
 824                 return self::getInterwikiLookup()->fetch( $this->mInterwiki )->isTranscludable();
 825         }
 826
 827         /**
 828          * Returns the DB name of the distant wiki which owns the object.
 829          *
 830          * @return string The DB name
 831          */
 832         public function getTransWikiID() {
 833                 if ( !$this->isExternal() ) {
 834                         return false;
 835                 }
 836
 837                 return self::getInterwikiLookup()->fetch( $this->mInterwiki )->getWikiID();
 838         }
 839
 840         /**
 841          * Get a TitleValue object representing this Title.
 842          *
 843          * @note Not all valid Titles have a corresponding valid TitleValue
 844          * (e.g. TitleValues cannot represent page-local links that have a
 845          * fragment but no title text).
 846          *
 847          * @return TitleValue|null
 848          */
 849         public function getTitleValue() {
 850                 if ( $this->mTitleValue === null ) {
 851                         try {
 852                                 $this->mTitleValue = new TitleValue(
 853                                         $this->getNamespace(),
 854                                         $this->getDBkey(),
 855                                         $this->getFragment(),
 856                                         $this->getInterwiki()
 857                                 );
 858                         } catch ( InvalidArgumentException $ex ) {
 859                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 860                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 861                         }
 862                 }
 863
 864                 return $this->mTitleValue;
 865         }
 866
 867         /**
 868          * Get the text form (spaces not underscores) of the main part
 869          *
 870          * @return string Main part of the title
 871          */
 872         public function getText() {
 873                 return $this->mTextform;
 874         }
 875
 876         /**
 877          * Get the URL-encoded form of the main part
 878          *
 879          * @return string Main part of the title, URL-encoded
 880          */
 881         public function getPartialURL() {
 882                 return $this->mUrlform;
 883         }
 884
 885         /**
 886          * Get the main part with underscores
 887          *
 888          * @return string Main part of the title, with underscores
 889          */
 890         public function getDBkey() {
 891                 return $this->mDbkeyform;
 892         }
 893
 894         /**
 895          * Get the DB key with the initial letter case as specified by the user
 896          *
 897          * @return string DB key
 898          */
 899         function getUserCaseDBKey() {
 900                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 901                         return $this->mUserCaseDBKey;
 902                 } else {
 903                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 904                         return $this->mDbkeyform;
 905                 }
 906         }
 907
 908         /**
 909          * Get the namespace index, i.e. one of the NS_xxxx constants.
 910          *
 911          * @return int Namespace index
 912          */
 913         public function getNamespace() {
 914                 return $this->mNamespace;
 915         }
 916
 917         /**
 918          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 919          *
 920          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 921          * @return string Content model id
 922          */
 923         public function getContentModel( $flags = 0 ) {
 924                 if ( ( !$this->mContentModel || $flags === Title::GAID_FOR_UPDATE ) &&
 925                         $this->getArticleID( $flags )
 926                 ) {
 927                         $linkCache = LinkCache::singleton();
 928                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 929                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 930                 }
 931
 932                 if ( !$this->mContentModel ) {
 933                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 934                 }
 935
 936                 return $this->mContentModel;
 937         }
 938
 939         /**
 940          * Convenience method for checking a title's content model name
 941          *
 942          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 943          * @return bool True if $this->getContentModel() == $id
 944          */
 945         public function hasContentModel( $id ) {
 946                 return $this->getContentModel() == $id;
 947         }
 948
 949         /**
 950          * Get the namespace text
 951          *
 952          * @return string Namespace text
 953          */
 954         public function getNsText() {
 955                 if ( $this->isExternal() ) {
 956                         // This probably shouldn't even happen,
 957                         // but for interwiki transclusion it sometimes does.
 958                         // Use the canonical namespaces if possible to try to
 959                         // resolve a foreign namespace.
 960                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 961                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 962                         }
 963                 }
 964
 965                 try {
 966                         $formatter = self::getTitleFormatter();
 967                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 968                 } catch ( InvalidArgumentException $ex ) {
 969                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
 970                         return false;
 971                 }
 972         }
 973
 974         /**
 975          * Get the namespace text of the subject (rather than talk) page
 976          *
 977          * @return string Namespace text
 978          */
 979         public function getSubjectNsText() {
 980                 global $wgContLang;
 981                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 982         }
 983
 984         /**
 985          * Get the namespace text of the talk page
 986          *
 987          * @return string Namespace text
 988          */
 989         public function getTalkNsText() {
 990                 global $wgContLang;
 991                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
 992         }
 993
 994         /**
 995          * Could this title have a corresponding talk page?
 996          *
 997          * @return bool
 998          */
 999         public function canTalk() {
1000                 return MWNamespace::canTalk( $this->mNamespace );
1001         }
1002
1003         /**
1004          * Is this in a namespace that allows actual pages?
1005          *
1006          * @return bool
1007          */
1008         public function canExist() {
1009                 return $this->mNamespace >= NS_MAIN;
1010         }
1011
1012         /**
1013          * Can this title be added to a user's watchlist?
1014          *
1015          * @return bool
1016          */
1017         public function isWatchable() {
1018                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1019         }
1020
1021         /**
1022          * Returns true if this is a special page.
1023          *
1024          * @return bool
1025          */
1026         public function isSpecialPage() {
1027                 return $this->getNamespace() == NS_SPECIAL;
1028         }
1029
1030         /**
1031          * Returns true if this title resolves to the named special page
1032          *
1033          * @param string $name The special page name
1034          * @return bool
1035          */
1036         public function isSpecial( $name ) {
1037                 if ( $this->isSpecialPage() ) {
1038                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1039                         if ( $name == $thisName ) {
1040                                 return true;
1041                         }
1042                 }
1043                 return false;
1044         }
1045
1046         /**
1047          * If the Title refers to a special page alias which is not the local default, resolve
1048          * the alias, and localise the name as necessary.  Otherwise, return $this
1049          *
1050          * @return Title
1051          */
1052         public function fixSpecialName() {
1053                 if ( $this->isSpecialPage() ) {
1054                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1055                         if ( $canonicalName ) {
1056                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1057                                 if ( $localName != $this->mDbkeyform ) {
1058                                         return Title::makeTitle( NS_SPECIAL, $localName );
1059                                 }
1060                         }
1061                 }
1062                 return $this;
1063         }
1064
1065         /**
1066          * Returns true if the title is inside the specified namespace.
1067          *
1068          * Please make use of this instead of comparing to getNamespace()
1069          * This function is much more resistant to changes we may make
1070          * to namespaces than code that makes direct comparisons.
1071          * @param int $ns The namespace
1072          * @return bool
1073          * @since 1.19
1074          */
1075         public function inNamespace( $ns ) {
1076                 return MWNamespace::equals( $this->getNamespace(), $ns );
1077         }
1078
1079         /**
1080          * Returns true if the title is inside one of the specified namespaces.
1081          *
1082          * @param int|int[] $namespaces,... The namespaces to check for
1083          * @return bool
1084          * @since 1.19
1085          */
1086         public function inNamespaces( /* ... */ ) {
1087                 $namespaces = func_get_args();
1088                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1089                         $namespaces = $namespaces[0];
1090                 }
1091
1092                 foreach ( $namespaces as $ns ) {
1093                         if ( $this->inNamespace( $ns ) ) {
1094                                 return true;
1095                         }
1096                 }
1097
1098                 return false;
1099         }
1100
1101         /**
1102          * Returns true if the title has the same subject namespace as the
1103          * namespace specified.
1104          * For example this method will take NS_USER and return true if namespace
1105          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1106          * as their subject namespace.
1107          *
1108          * This is MUCH simpler than individually testing for equivalence
1109          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1110          * @since 1.19
1111          * @param int $ns
1112          * @return bool
1113          */
1114         public function hasSubjectNamespace( $ns ) {
1115                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1116         }
1117
1118         /**
1119          * Is this Title in a namespace which contains content?
1120          * In other words, is this a content page, for the purposes of calculating
1121          * statistics, etc?
1122          *
1123          * @return bool
1124          */
1125         public function isContentPage() {
1126                 return MWNamespace::isContent( $this->getNamespace() );
1127         }
1128
1129         /**
1130          * Would anybody with sufficient privileges be able to move this page?
1131          * Some pages just aren't movable.
1132          *
1133          * @return bool
1134          */
1135         public function isMovable() {
1136                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1137                         // Interwiki title or immovable namespace. Hooks don't get to override here
1138                         return false;
1139                 }
1140
1141                 $result = true;
1142                 Hooks::run( 'TitleIsMovable', [ $this, &$result ] );
1143                 return $result;
1144         }
1145
1146         /**
1147          * Is this the mainpage?
1148          * @note Title::newFromText seems to be sufficiently optimized by the title
1149          * cache that we don't need to over-optimize by doing direct comparisons and
1150          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1151          * ends up reporting something differently than $title->isMainPage();
1152          *
1153          * @since 1.18
1154          * @return bool
1155          */
1156         public function isMainPage() {
1157                 return $this->equals( Title::newMainPage() );
1158         }
1159
1160         /**
1161          * Is this a subpage?
1162          *
1163          * @return bool
1164          */
1165         public function isSubpage() {
1166                 return MWNamespace::hasSubpages( $this->mNamespace )
1167                         ? strpos( $this->getText(), '/' ) !== false
1168                         : false;
1169         }
1170
1171         /**
1172          * Is this a conversion table for the LanguageConverter?
1173          *
1174          * @return bool
1175          */
1176         public function isConversionTable() {
1177                 // @todo ConversionTable should become a separate content model.
1178
1179                 return $this->getNamespace() == NS_MEDIAWIKI &&
1180                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1181         }
1182
1183         /**
1184          * Does that page contain wikitext, or it is JS, CSS or whatever?
1185          *
1186          * @return bool
1187          */
1188         public function isWikitextPage() {
1189                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1190         }
1191
1192         /**
1193          * Could this page contain custom CSS or JavaScript for the global UI.
1194          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1195          * or CONTENT_MODEL_JAVASCRIPT.
1196          *
1197          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1198          * for that!
1199          *
1200          * Note that this method should not return true for pages that contain and
1201          * show "inactive" CSS or JS.
1202          *
1203          * @return bool
1204          * @todo FIXME: Rename to isSiteConfigPage() and remove deprecated hook
1205          */
1206         public function isCssOrJsPage() {
1207                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1208                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1209                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1210
1211                 # @note This hook is also called in ContentHandler::getDefaultModel.
1212                 #   It's called here again to make sure hook functions can force this
1213                 #   method to return true even outside the MediaWiki namespace.
1214
1215                 Hooks::run( 'TitleIsCssOrJsPage', [ $this, &$isCssOrJsPage ], '1.25' );
1216
1217                 return $isCssOrJsPage;
1218         }
1219
1220         /**
1221          * Is this a .css or .js subpage of a user page?
1222          * @return bool
1223          * @todo FIXME: Rename to isUserConfigPage()
1224          */
1225         public function isCssJsSubpage() {
1226                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1227                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1228                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1229         }
1230
1231         /**
1232          * Trim down a .css or .js subpage title to get the corresponding skin name
1233          *
1234          * @return string Containing skin name from .css or .js subpage title
1235          */
1236         public function getSkinFromCssJsSubpage() {
1237                 $subpage = explode( '/', $this->mTextform );
1238                 $subpage = $subpage[count( $subpage ) - 1];
1239                 $lastdot = strrpos( $subpage, '.' );
1240                 if ( $lastdot === false ) {
1241                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1242                 }
1243                 return substr( $subpage, 0, $lastdot );
1244         }
1245
1246         /**
1247          * Is this a .css subpage of a user page?
1248          *
1249          * @return bool
1250          */
1251         public function isCssSubpage() {
1252                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1253                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1254         }
1255
1256         /**
1257          * Is this a .js subpage of a user page?
1258          *
1259          * @return bool
1260          */
1261         public function isJsSubpage() {
1262                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1263                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1264         }
1265
1266         /**
1267          * Is this a talk page of some sort?
1268          *
1269          * @return bool
1270          */
1271         public function isTalkPage() {
1272                 return MWNamespace::isTalk( $this->getNamespace() );
1273         }
1274
1275         /**
1276          * Get a Title object associated with the talk page of this article
1277          *
1278          * @return Title The object for the talk page
1279          */
1280         public function getTalkPage() {
1281                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1282         }
1283
1284         /**
1285          * Get a title object associated with the subject page of this
1286          * talk page
1287          *
1288          * @return Title The object for the subject page
1289          */
1290         public function getSubjectPage() {
1291                 // Is this the same title?
1292                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1293                 if ( $this->getNamespace() == $subjectNS ) {
1294                         return $this;
1295                 }
1296                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1297         }
1298
1299         /**
1300          * Get the other title for this page, if this is a subject page
1301          * get the talk page, if it is a subject page get the talk page
1302          *
1303          * @since 1.25
1304          * @throws MWException
1305          * @return Title
1306          */
1307         public function getOtherPage() {
1308                 if ( $this->isSpecialPage() ) {
1309                         throw new MWException( 'Special pages cannot have other pages' );
1310                 }
1311                 if ( $this->isTalkPage() ) {
1312                         return $this->getSubjectPage();
1313                 } else {
1314                         return $this->getTalkPage();
1315                 }
1316         }
1317
1318         /**
1319          * Get the default namespace index, for when there is no namespace
1320          *
1321          * @return int Default namespace index
1322          */
1323         public function getDefaultNamespace() {
1324                 return $this->mDefaultNamespace;
1325         }
1326
1327         /**
1328          * Get the Title fragment (i.e.\ the bit after the #) in text form
1329          *
1330          * Use Title::hasFragment to check for a fragment
1331          *
1332          * @return string Title fragment
1333          */
1334         public function getFragment() {
1335                 return $this->mFragment;
1336         }
1337
1338         /**
1339          * Check if a Title fragment is set
1340          *
1341          * @return bool
1342          * @since 1.23
1343          */
1344         public function hasFragment() {
1345                 return $this->mFragment !== '';
1346         }
1347
1348         /**
1349          * Get the fragment in URL form, including the "#" character if there is one
1350          * @return string Fragment in URL form
1351          */
1352         public function getFragmentForURL() {
1353                 if ( !$this->hasFragment() ) {
1354                         return '';
1355                 } else {
1356                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1357                 }
1358         }
1359
1360         /**
1361          * Set the fragment for this title. Removes the first character from the
1362          * specified fragment before setting, so it assumes you're passing it with
1363          * an initial "#".
1364          *
1365          * Deprecated for public use, use Title::makeTitle() with fragment parameter,
1366          * or Title::createFragmentTarget().
1367          * Still in active use privately.
1368          *
1369          * @private
1370          * @param string $fragment Text
1371          */
1372         public function setFragment( $fragment ) {
1373                 $this->mFragment = strtr( substr( $fragment, 1 ), '_', ' ' );
1374         }
1375
1376         /**
1377          * Creates a new Title for a different fragment of the same page.
1378          *
1379          * @since 1.27
1380          * @param string $fragment
1381          * @return Title
1382          */
1383         public function createFragmentTarget( $fragment ) {
1384                 return self::makeTitle(
1385                         $this->getNamespace(),
1386                         $this->getText(),
1387                         $fragment,
1388                         $this->getInterwiki()
1389                 );
1390
1391         }
1392
1393         /**
1394          * Prefix some arbitrary text with the namespace or interwiki prefix
1395          * of this object
1396          *
1397          * @param string $name The text
1398          * @return string The prefixed text
1399          */
1400         private function prefix( $name ) {
1401                 $p = '';
1402                 if ( $this->isExternal() ) {
1403                         $p = $this->mInterwiki . ':';
1404                 }
1405
1406                 if ( 0 != $this->mNamespace ) {
1407                         $p .= $this->getNsText() . ':';
1408                 }
1409                 return $p . $name;
1410         }
1411
1412         /**
1413          * Get the prefixed database key form
1414          *
1415          * @return string The prefixed title, with underscores and
1416          *  any interwiki and namespace prefixes
1417          */
1418         public function getPrefixedDBkey() {
1419                 $s = $this->prefix( $this->mDbkeyform );
1420                 $s = strtr( $s, ' ', '_' );
1421                 return $s;
1422         }
1423
1424         /**
1425          * Get the prefixed title with spaces.
1426          * This is the form usually used for display
1427          *
1428          * @return string The prefixed title, with spaces
1429          */
1430         public function getPrefixedText() {
1431                 if ( $this->mPrefixedText === null ) {
1432                         $s = $this->prefix( $this->mTextform );
1433                         $s = strtr( $s, '_', ' ' );
1434                         $this->mPrefixedText = $s;
1435                 }
1436                 return $this->mPrefixedText;
1437         }
1438
1439         /**
1440          * Return a string representation of this title
1441          *
1442          * @return string Representation of this title
1443          */
1444         public function __toString() {
1445                 return $this->getPrefixedText();
1446         }
1447
1448         /**
1449          * Get the prefixed title with spaces, plus any fragment
1450          * (part beginning with '#')
1451          *
1452          * @return string The prefixed title, with spaces and the fragment, including '#'
1453          */
1454         public function getFullText() {
1455                 $text = $this->getPrefixedText();
1456                 if ( $this->hasFragment() ) {
1457                         $text .= '#' . $this->getFragment();
1458                 }
1459                 return $text;
1460         }
1461
1462         /**
1463          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1464          *
1465          * @par Example:
1466          * @code
1467          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1468          * # returns: 'Foo'
1469          * @endcode
1470          *
1471          * @return string Root name
1472          * @since 1.20
1473          */
1474         public function getRootText() {
1475                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1476                         return $this->getText();
1477                 }
1478
1479                 return strtok( $this->getText(), '/' );
1480         }
1481
1482         /**
1483          * Get the root page name title, i.e. the leftmost part before any slashes
1484          *
1485          * @par Example:
1486          * @code
1487          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1488          * # returns: Title{User:Foo}
1489          * @endcode
1490          *
1491          * @return Title Root title
1492          * @since 1.20
1493          */
1494         public function getRootTitle() {
1495                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1496         }
1497
1498         /**
1499          * Get the base page name without a namespace, i.e. the part before the subpage name
1500          *
1501          * @par Example:
1502          * @code
1503          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1504          * # returns: 'Foo/Bar'
1505          * @endcode
1506          *
1507          * @return string Base name
1508          */
1509         public function getBaseText() {
1510                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1511                         return $this->getText();
1512                 }
1513
1514                 $parts = explode( '/', $this->getText() );
1515                 # Don't discard the real title if there's no subpage involved
1516                 if ( count( $parts ) > 1 ) {
1517                         unset( $parts[count( $parts ) - 1] );
1518                 }
1519                 return implode( '/', $parts );
1520         }
1521
1522         /**
1523          * Get the base page name title, i.e. the part before the subpage name
1524          *
1525          * @par Example:
1526          * @code
1527          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1528          * # returns: Title{User:Foo/Bar}
1529          * @endcode
1530          *
1531          * @return Title Base title
1532          * @since 1.20
1533          */
1534         public function getBaseTitle() {
1535                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1536         }
1537
1538         /**
1539          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1540          *
1541          * @par Example:
1542          * @code
1543          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1544          * # returns: "Baz"
1545          * @endcode
1546          *
1547          * @return string Subpage name
1548          */
1549         public function getSubpageText() {
1550                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1551                         return $this->mTextform;
1552                 }
1553                 $parts = explode( '/', $this->mTextform );
1554                 return $parts[count( $parts ) - 1];
1555         }
1556
1557         /**
1558          * Get the title for a subpage of the current page
1559          *
1560          * @par Example:
1561          * @code
1562          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1563          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1564          * @endcode
1565          *
1566          * @param string $text The subpage name to add to the title
1567          * @return Title Subpage title
1568          * @since 1.20
1569          */
1570         public function getSubpage( $text ) {
1571                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1572         }
1573
1574         /**
1575          * Get a URL-encoded form of the subpage text
1576          *
1577          * @return string URL-encoded subpage name
1578          */
1579         public function getSubpageUrlForm() {
1580                 $text = $this->getSubpageText();
1581                 $text = wfUrlencode( strtr( $text, ' ', '_' ) );
1582                 return $text;
1583         }
1584
1585         /**
1586          * Get a URL-encoded title (not an actual URL) including interwiki
1587          *
1588          * @return string The URL-encoded form
1589          */
1590         public function getPrefixedURL() {
1591                 $s = $this->prefix( $this->mDbkeyform );
1592                 $s = wfUrlencode( strtr( $s, ' ', '_' ) );
1593                 return $s;
1594         }
1595
1596         /**
1597          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1598          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1599          * second argument named variant. This was deprecated in favor
1600          * of passing an array of option with a "variant" key
1601          * Once $query2 is removed for good, this helper can be dropped
1602          * and the wfArrayToCgi moved to getLocalURL();
1603          *
1604          * @since 1.19 (r105919)
1605          * @param array|string $query
1606          * @param bool $query2
1607          * @return string
1608          */
1609         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1610                 if ( $query2 !== false ) {
1611                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1612                                 "method called with a second parameter is deprecated. Add your " .
1613                                 "parameter to an array passed as the first parameter.", "1.19" );
1614                 }
1615                 if ( is_array( $query ) ) {
1616                         $query = wfArrayToCgi( $query );
1617                 }
1618                 if ( $query2 ) {
1619                         if ( is_string( $query2 ) ) {
1620                                 // $query2 is a string, we will consider this to be
1621                                 // a deprecated $variant argument and add it to the query
1622                                 $query2 = wfArrayToCgi( [ 'variant' => $query2 ] );
1623                         } else {
1624                                 $query2 = wfArrayToCgi( $query2 );
1625                         }
1626                         // If we have $query content add a & to it first
1627                         if ( $query ) {
1628                                 $query .= '&';
1629                         }
1630                         // Now append the queries together
1631                         $query .= $query2;
1632                 }
1633                 return $query;
1634         }
1635
1636         /**
1637          * Get a real URL referring to this title, with interwiki link and
1638          * fragment
1639          *
1640          * @see self::getLocalURL for the arguments.
1641          * @see wfExpandUrl
1642          * @param array|string $query
1643          * @param bool $query2
1644          * @param string $proto Protocol type to use in URL
1645          * @return string The URL
1646          */
1647         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1648                 $query = self::fixUrlQueryArgs( $query, $query2 );
1649
1650                 # Hand off all the decisions on urls to getLocalURL
1651                 $url = $this->getLocalURL( $query );
1652
1653                 # Expand the url to make it a full url. Note that getLocalURL has the
1654                 # potential to output full urls for a variety of reasons, so we use
1655                 # wfExpandUrl instead of simply prepending $wgServer
1656                 $url = wfExpandUrl( $url, $proto );
1657
1658                 # Finally, add the fragment.
1659                 $url .= $this->getFragmentForURL();
1660
1661                 Hooks::run( 'GetFullURL', [ &$this, &$url, $query ] );
1662                 return $url;
1663         }
1664
1665         /**
1666          * Get a URL with no fragment or server name (relative URL) from a Title object.
1667          * If this page is generated with action=render, however,
1668          * $wgServer is prepended to make an absolute URL.
1669          *
1670          * @see self::getFullURL to always get an absolute URL.
1671          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1672          *  valid to link, locally, to the current Title.
1673          * @see self::newFromText to produce a Title object.
1674          *
1675          * @param string|array $query An optional query string,
1676          *   not used for interwiki links. Can be specified as an associative array as well,
1677          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1678          *   Some query patterns will trigger various shorturl path replacements.
1679          * @param array $query2 An optional secondary query array. This one MUST
1680          *   be an array. If a string is passed it will be interpreted as a deprecated
1681          *   variant argument and urlencoded into a variant= argument.
1682          *   This second query argument will be added to the $query
1683          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1684          *   pair in the first parameter array instead.
1685          *
1686          * @return string String of the URL.
1687          */
1688         public function getLocalURL( $query = '', $query2 = false ) {
1689                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1690
1691                 $query = self::fixUrlQueryArgs( $query, $query2 );
1692
1693                 $interwiki = self::getInterwikiLookup()->fetch( $this->mInterwiki );
1694                 if ( $interwiki ) {
1695                         $namespace = $this->getNsText();
1696                         if ( $namespace != '' ) {
1697                                 # Can this actually happen? Interwikis shouldn't be parsed.
1698                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1699                                 $namespace .= ':';
1700                         }
1701                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1702                         $url = wfAppendQuery( $url, $query );
1703                 } else {
1704                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1705                         if ( $query == '' ) {
1706                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1707                                 Hooks::run( 'GetLocalURL::Article', [ &$this, &$url ] );
1708                         } else {
1709                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1710                                 $url = false;
1711                                 $matches = [];
1712
1713                                 if ( !empty( $wgActionPaths )
1714                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1715                                 ) {
1716                                         $action = urldecode( $matches[2] );
1717                                         if ( isset( $wgActionPaths[$action] ) ) {
1718                                                 $query = $matches[1];
1719                                                 if ( isset( $matches[4] ) ) {
1720                                                         $query .= $matches[4];
1721                                                 }
1722                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1723                                                 if ( $query != '' ) {
1724                                                         $url = wfAppendQuery( $url, $query );
1725                                                 }
1726                                         }
1727                                 }
1728
1729                                 if ( $url === false
1730                                         && $wgVariantArticlePath
1731                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1732                                         && $this->getPageLanguage()->equals( $wgContLang )
1733                                         && $this->getPageLanguage()->hasVariants()
1734                                 ) {
1735                                         $variant = urldecode( $matches[1] );
1736                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1737                                                 // Only do the variant replacement if the given variant is a valid
1738                                                 // variant for the page's language.
1739                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1740                                                 $url = str_replace( '$1', $dbkey, $url );
1741                                         }
1742                                 }
1743
1744                                 if ( $url === false ) {
1745                                         if ( $query == '-' ) {
1746                                                 $query = '';
1747                                         }
1748                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1749                                 }
1750                         }
1751
1752                         Hooks::run( 'GetLocalURL::Internal', [ &$this, &$url, $query ] );
1753
1754                         // @todo FIXME: This causes breakage in various places when we
1755                         // actually expected a local URL and end up with dupe prefixes.
1756                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1757                                 $url = $wgServer . $url;
1758                         }
1759                 }
1760                 Hooks::run( 'GetLocalURL', [ &$this, &$url, $query ] );
1761                 return $url;
1762         }
1763
1764         /**
1765          * Get a URL that's the simplest URL that will be valid to link, locally,
1766          * to the current Title.  It includes the fragment, but does not include
1767          * the server unless action=render is used (or the link is external).  If
1768          * there's a fragment but the prefixed text is empty, we just return a link
1769          * to the fragment.
1770          *
1771          * The result obviously should not be URL-escaped, but does need to be
1772          * HTML-escaped if it's being output in HTML.
1773          *
1774          * @param array $query
1775          * @param bool $query2
1776          * @param string|int|bool $proto A PROTO_* constant on how the URL should be expanded,
1777          *                               or false (default) for no expansion
1778          * @see self::getLocalURL for the arguments.
1779          * @return string The URL
1780          */
1781         public function getLinkURL( $query = '', $query2 = false, $proto = false ) {
1782                 if ( $this->isExternal() || $proto !== false ) {
1783                         $ret = $this->getFullURL( $query, $query2, $proto );
1784                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1785                         $ret = $this->getFragmentForURL();
1786                 } else {
1787                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1788                 }
1789                 return $ret;
1790         }
1791
1792         /**
1793          * Get the URL form for an internal link.
1794          * - Used in various CDN-related code, in case we have a different
1795          * internal hostname for the server from the exposed one.
1796          *
1797          * This uses $wgInternalServer to qualify the path, or $wgServer
1798          * if $wgInternalServer is not set. If the server variable used is
1799          * protocol-relative, the URL will be expanded to http://
1800          *
1801          * @see self::getLocalURL for the arguments.
1802          * @return string The URL
1803          */
1804         public function getInternalURL( $query = '', $query2 = false ) {
1805                 global $wgInternalServer, $wgServer;
1806                 $query = self::fixUrlQueryArgs( $query, $query2 );
1807                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1808                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1809                 Hooks::run( 'GetInternalURL', [ &$this, &$url, $query ] );
1810                 return $url;
1811         }
1812
1813         /**
1814          * Get the URL for a canonical link, for use in things like IRC and
1815          * e-mail notifications. Uses $wgCanonicalServer and the
1816          * GetCanonicalURL hook.
1817          *
1818          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1819          *
1820          * @see self::getLocalURL for the arguments.
1821          * @return string The URL
1822          * @since 1.18
1823          */
1824         public function getCanonicalURL( $query = '', $query2 = false ) {
1825                 $query = self::fixUrlQueryArgs( $query, $query2 );
1826                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1827                 Hooks::run( 'GetCanonicalURL', [ &$this, &$url, $query ] );
1828                 return $url;
1829         }
1830
1831         /**
1832          * Get the edit URL for this Title
1833          *
1834          * @return string The URL, or a null string if this is an interwiki link
1835          */
1836         public function getEditURL() {
1837                 if ( $this->isExternal() ) {
1838                         return '';
1839                 }
1840                 $s = $this->getLocalURL( 'action=edit' );
1841
1842                 return $s;
1843         }
1844
1845         /**
1846          * Can $user perform $action on this page?
1847          * This skips potentially expensive cascading permission checks
1848          * as well as avoids expensive error formatting
1849          *
1850          * Suitable for use for nonessential UI controls in common cases, but
1851          * _not_ for functional access control.
1852          *
1853          * May provide false positives, but should never provide a false negative.
1854          *
1855          * @param string $action Action that permission needs to be checked for
1856          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1857          * @return bool
1858          */
1859         public function quickUserCan( $action, $user = null ) {
1860                 return $this->userCan( $action, $user, false );
1861         }
1862
1863         /**
1864          * Can $user perform $action on this page?
1865          *
1866          * @param string $action Action that permission needs to be checked for
1867          * @param User $user User to check (since 1.19); $wgUser will be used if not
1868          *   provided.
1869          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1870          * @return bool
1871          */
1872         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1873                 if ( !$user instanceof User ) {
1874                         global $wgUser;
1875                         $user = $wgUser;
1876                 }
1877
1878                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1879         }
1880
1881         /**
1882          * Can $user perform $action on this page?
1883          *
1884          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1885          *
1886          * @param string $action Action that permission needs to be checked for
1887          * @param User $user User to check
1888          * @param string $rigor One of (quick,full,secure)
1889          *   - quick  : does cheap permission checks from replica DBs (usable for GUI creation)
1890          *   - full   : does cheap and expensive checks possibly from a replica DB
1891          *   - secure : does cheap and expensive checks, using the master as needed
1892          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1893          *   whose corresponding errors may be ignored.
1894          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
1895          */
1896         public function getUserPermissionsErrors(
1897                 $action, $user, $rigor = 'secure', $ignoreErrors = []
1898         ) {
1899                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1900
1901                 // Remove the errors being ignored.
1902                 foreach ( $errors as $index => $error ) {
1903                         $errKey = is_array( $error ) ? $error[0] : $error;
1904
1905                         if ( in_array( $errKey, $ignoreErrors ) ) {
1906                                 unset( $errors[$index] );
1907                         }
1908                         if ( $errKey instanceof MessageSpecifier && in_array( $errKey->getKey(), $ignoreErrors ) ) {
1909                                 unset( $errors[$index] );
1910                         }
1911                 }
1912
1913                 return $errors;
1914         }
1915
1916         /**
1917          * Permissions checks that fail most often, and which are easiest to test.
1918          *
1919          * @param string $action The action to check
1920          * @param User $user User to check
1921          * @param array $errors List of current errors
1922          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1923          * @param bool $short Short circuit on first error
1924          *
1925          * @return array List of errors
1926          */
1927         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1928                 if ( !Hooks::run( 'TitleQuickPermissions',
1929                         [ $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ] )
1930                 ) {
1931                         return $errors;
1932                 }
1933
1934                 if ( $action == 'create' ) {
1935                         if (
1936                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1937                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1938                         ) {
1939                                 $errors[] = $user->isAnon() ? [ 'nocreatetext' ] : [ 'nocreate-loggedin' ];
1940                         }
1941                 } elseif ( $action == 'move' ) {
1942                         if ( !$user->isAllowed( 'move-rootuserpages' )
1943                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1944                                 // Show user page-specific message only if the user can move other pages
1945                                 $errors[] = [ 'cant-move-user-page' ];
1946                         }
1947
1948                         // Check if user is allowed to move files if it's a file
1949                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1950                                 $errors[] = [ 'movenotallowedfile' ];
1951                         }
1952
1953                         // Check if user is allowed to move category pages if it's a category page
1954                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1955                                 $errors[] = [ 'cant-move-category-page' ];
1956                         }
1957
1958                         if ( !$user->isAllowed( 'move' ) ) {
1959                                 // User can't move anything
1960                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1961                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1962                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1963                                         // custom message if logged-in users without any special rights can move
1964                                         $errors[] = [ 'movenologintext' ];
1965                                 } else {
1966                                         $errors[] = [ 'movenotallowed' ];
1967                                 }
1968                         }
1969                 } elseif ( $action == 'move-target' ) {
1970                         if ( !$user->isAllowed( 'move' ) ) {
1971                                 // User can't move anything
1972                                 $errors[] = [ 'movenotallowed' ];
1973                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1974                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1975                                 // Show user page-specific message only if the user can move other pages
1976                                 $errors[] = [ 'cant-move-to-user-page' ];
1977                         } elseif ( !$user->isAllowed( 'move-categorypages' )
1978                                         && $this->mNamespace == NS_CATEGORY ) {
1979                                 // Show category page-specific message only if the user can move other pages
1980                                 $errors[] = [ 'cant-move-to-category-page' ];
1981                         }
1982                 } elseif ( !$user->isAllowed( $action ) ) {
1983                         $errors[] = $this->missingPermissionError( $action, $short );
1984                 }
1985
1986                 return $errors;
1987         }
1988
1989         /**
1990          * Add the resulting error code to the errors array
1991          *
1992          * @param array $errors List of current errors
1993          * @param array $result Result of errors
1994          *
1995          * @return array List of errors
1996          */
1997         private function resultToError( $errors, $result ) {
1998                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1999                         // A single array representing an error
2000                         $errors[] = $result;
2001                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2002                         // A nested array representing multiple errors
2003                         $errors = array_merge( $errors, $result );
2004                 } elseif ( $result !== '' && is_string( $result ) ) {
2005                         // A string representing a message-id
2006                         $errors[] = [ $result ];
2007                 } elseif ( $result instanceof MessageSpecifier ) {
2008                         // A message specifier representing an error
2009                         $errors[] = [ $result ];
2010                 } elseif ( $result === false ) {
2011                         // a generic "We don't want them to do that"
2012                         $errors[] = [ 'badaccess-group0' ];
2013                 }
2014                 return $errors;
2015         }
2016
2017         /**
2018          * Check various permission hooks
2019          *
2020          * @param string $action The action to check
2021          * @param User $user User to check
2022          * @param array $errors List of current errors
2023          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2024          * @param bool $short Short circuit on first error
2025          *
2026          * @return array List of errors
2027          */
2028         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2029                 // Use getUserPermissionsErrors instead
2030                 $result = '';
2031                 if ( !Hooks::run( 'userCan', [ &$this, &$user, $action, &$result ] ) ) {
2032                         return $result ? [] : [ [ 'badaccess-group0' ] ];
2033                 }
2034                 // Check getUserPermissionsErrors hook
2035                 if ( !Hooks::run( 'getUserPermissionsErrors', [ &$this, &$user, $action, &$result ] ) ) {
2036                         $errors = $this->resultToError( $errors, $result );
2037                 }
2038                 // Check getUserPermissionsErrorsExpensive hook
2039                 if (
2040                         $rigor !== 'quick'
2041                         && !( $short && count( $errors ) > 0 )
2042                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', [ &$this, &$user, $action, &$result ] )
2043                 ) {
2044                         $errors = $this->resultToError( $errors, $result );
2045                 }
2046
2047                 return $errors;
2048         }
2049
2050         /**
2051          * Check permissions on special pages & namespaces
2052          *
2053          * @param string $action The action to check
2054          * @param User $user User to check
2055          * @param array $errors List of current errors
2056          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2057          * @param bool $short Short circuit on first error
2058          *
2059          * @return array List of errors
2060          */
2061         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2062                 # Only 'createaccount' can be performed on special pages,
2063                 # which don't actually exist in the DB.
2064                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2065                         $errors[] = [ 'ns-specialprotected' ];
2066                 }
2067
2068                 # Check $wgNamespaceProtection for restricted namespaces
2069                 if ( $this->isNamespaceProtected( $user ) ) {
2070                         $ns = $this->mNamespace == NS_MAIN ?
2071                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2072                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2073                                 [ 'protectedinterface', $action ] : [ 'namespaceprotected', $ns, $action ];
2074                 }
2075
2076                 return $errors;
2077         }
2078
2079         /**
2080          * Check CSS/JS sub-page permissions
2081          *
2082          * @param string $action The action to check
2083          * @param User $user User to check
2084          * @param array $errors List of current errors
2085          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2086          * @param bool $short Short circuit on first error
2087          *
2088          * @return array List of errors
2089          */
2090         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2091                 # Protect css/js subpages of user pages
2092                 # XXX: this might be better using restrictions
2093                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2094                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2095                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2096                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2097                                         $errors[] = [ 'mycustomcssprotected', $action ];
2098                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2099                                         $errors[] = [ 'mycustomjsprotected', $action ];
2100                                 }
2101                         } else {
2102                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2103                                         $errors[] = [ 'customcssprotected', $action ];
2104                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2105                                         $errors[] = [ 'customjsprotected', $action ];
2106                                 }
2107                         }
2108                 }
2109
2110                 return $errors;
2111         }
2112
2113         /**
2114          * Check against page_restrictions table requirements on this
2115          * page. The user must possess all required rights for this
2116          * action.
2117          *
2118          * @param string $action The action to check
2119          * @param User $user User to check
2120          * @param array $errors List of current errors
2121          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2122          * @param bool $short Short circuit on first error
2123          *
2124          * @return array List of errors
2125          */
2126         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2127                 foreach ( $this->getRestrictions( $action ) as $right ) {
2128                         // Backwards compatibility, rewrite sysop -> editprotected
2129                         if ( $right == 'sysop' ) {
2130                                 $right = 'editprotected';
2131                         }
2132                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2133                         if ( $right == 'autoconfirmed' ) {
2134                                 $right = 'editsemiprotected';
2135                         }
2136                         if ( $right == '' ) {
2137                                 continue;
2138                         }
2139                         if ( !$user->isAllowed( $right ) ) {
2140                                 $errors[] = [ 'protectedpagetext', $right, $action ];
2141                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2142                                 $errors[] = [ 'protectedpagetext', 'protect', $action ];
2143                         }
2144                 }
2145
2146                 return $errors;
2147         }
2148
2149         /**
2150          * Check restrictions on cascading pages.
2151          *
2152          * @param string $action The action to check
2153          * @param User $user User to check
2154          * @param array $errors List of current errors
2155          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2156          * @param bool $short Short circuit on first error
2157          *
2158          * @return array List of errors
2159          */
2160         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2161                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2162                         # We /could/ use the protection level on the source page, but it's
2163                         # fairly ugly as we have to establish a precedence hierarchy for pages
2164                         # included by multiple cascade-protected pages. So just restrict
2165                         # it to people with 'protect' permission, as they could remove the
2166                         # protection anyway.
2167                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2168                         # Cascading protection depends on more than this page...
2169                         # Several cascading protected pages may include this page...
2170                         # Check each cascading level
2171                         # This is only for protection restrictions, not for all actions
2172                         if ( isset( $restrictions[$action] ) ) {
2173                                 foreach ( $restrictions[$action] as $right ) {
2174                                         // Backwards compatibility, rewrite sysop -> editprotected
2175                                         if ( $right == 'sysop' ) {
2176                                                 $right = 'editprotected';
2177                                         }
2178                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2179                                         if ( $right == 'autoconfirmed' ) {
2180                                                 $right = 'editsemiprotected';
2181                                         }
2182                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2183                                                 $pages = '';
2184                                                 foreach ( $cascadingSources as $page ) {
2185                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2186                                                 }
2187                                                 $errors[] = [ 'cascadeprotected', count( $cascadingSources ), $pages, $action ];
2188                                         }
2189                                 }
2190                         }
2191                 }
2192
2193                 return $errors;
2194         }
2195
2196         /**
2197          * Check action permissions not already checked in checkQuickPermissions
2198          *
2199          * @param string $action The action to check
2200          * @param User $user User to check
2201          * @param array $errors List of current errors
2202          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2203          * @param bool $short Short circuit on first error
2204          *
2205          * @return array List of errors
2206          */
2207         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2208                 global $wgDeleteRevisionsLimit, $wgLang;
2209
2210                 if ( $action == 'protect' ) {
2211                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2212                                 // If they can't edit, they shouldn't protect.
2213                                 $errors[] = [ 'protect-cantedit' ];
2214                         }
2215                 } elseif ( $action == 'create' ) {
2216                         $title_protection = $this->getTitleProtection();
2217                         if ( $title_protection ) {
2218                                 if ( $title_protection['permission'] == ''
2219                                         || !$user->isAllowed( $title_protection['permission'] )
2220                                 ) {
2221                                         $errors[] = [
2222                                                 'titleprotected',
2223                                                 User::whoIs( $title_protection['user'] ),
2224                                                 $title_protection['reason']
2225                                         ];
2226                                 }
2227                         }
2228                 } elseif ( $action == 'move' ) {
2229                         // Check for immobile pages
2230                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2231                                 // Specific message for this case
2232                                 $errors[] = [ 'immobile-source-namespace', $this->getNsText() ];
2233                         } elseif ( !$this->isMovable() ) {
2234                                 // Less specific message for rarer cases
2235                                 $errors[] = [ 'immobile-source-page' ];
2236                         }
2237                 } elseif ( $action == 'move-target' ) {
2238                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2239                                 $errors[] = [ 'immobile-target-namespace', $this->getNsText() ];
2240                         } elseif ( !$this->isMovable() ) {
2241                                 $errors[] = [ 'immobile-target-page' ];
2242                         }
2243                 } elseif ( $action == 'delete' ) {
2244                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, [], $rigor, true );
2245                         if ( !$tempErrors ) {
2246                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2247                                         $user, $tempErrors, $rigor, true );
2248                         }
2249                         if ( $tempErrors ) {
2250                                 // If protection keeps them from editing, they shouldn't be able to delete.
2251                                 $errors[] = [ 'deleteprotected' ];
2252                         }
2253                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2254                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2255                         ) {
2256                                 $errors[] = [ 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) ];
2257                         }
2258                 }
2259                 return $errors;
2260         }
2261
2262         /**
2263          * Check that the user isn't blocked from editing.
2264          *
2265          * @param string $action The action to check
2266          * @param User $user User to check
2267          * @param array $errors List of current errors
2268          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2269          * @param bool $short Short circuit on first error
2270          *
2271          * @return array List of errors
2272          */
2273         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2274                 global $wgEmailConfirmToEdit, $wgBlockDisablesLogin;
2275                 // Account creation blocks handled at userlogin.
2276                 // Unblocking handled in SpecialUnblock
2277                 if ( $rigor === 'quick' || in_array( $action, [ 'createaccount', 'unblock' ] ) ) {
2278                         return $errors;
2279                 }
2280
2281                 // Optimize for a very common case
2282                 if ( $action === 'read' && !$wgBlockDisablesLogin ) {
2283                         return $errors;
2284                 }
2285
2286                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2287                         $errors[] = [ 'confirmedittext' ];
2288                 }
2289
2290                 $useSlave = ( $rigor !== 'secure' );
2291                 if ( ( $action == 'edit' || $action == 'create' )
2292                         && !$user->isBlockedFrom( $this, $useSlave )
2293                 ) {
2294                         // Don't block the user from editing their own talk page unless they've been
2295                         // explicitly blocked from that too.
2296                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2297                         // @todo FIXME: Pass the relevant context into this function.
2298                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2299                 }
2300
2301                 return $errors;
2302         }
2303
2304         /**
2305          * Check that the user is allowed to read this page.
2306          *
2307          * @param string $action The action to check
2308          * @param User $user User to check
2309          * @param array $errors List of current errors
2310          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2311          * @param bool $short Short circuit on first error
2312          *
2313          * @return array List of errors
2314          */
2315         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2316                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2317
2318                 $whitelisted = false;
2319                 if ( User::isEveryoneAllowed( 'read' ) ) {
2320                         # Shortcut for public wikis, allows skipping quite a bit of code
2321                         $whitelisted = true;
2322                 } elseif ( $user->isAllowed( 'read' ) ) {
2323                         # If the user is allowed to read pages, he is allowed to read all pages
2324                         $whitelisted = true;
2325                 } elseif ( $this->isSpecial( 'Userlogin' )
2326                         || $this->isSpecial( 'PasswordReset' )
2327                         || $this->isSpecial( 'Userlogout' )
2328                 ) {
2329                         # Always grant access to the login page.
2330                         # Even anons need to be able to log in.
2331                         $whitelisted = true;
2332                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2333                         # Time to check the whitelist
2334                         # Only do these checks is there's something to check against
2335                         $name = $this->getPrefixedText();
2336                         $dbName = $this->getPrefixedDBkey();
2337
2338                         // Check for explicit whitelisting with and without underscores
2339                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2340                                 $whitelisted = true;
2341                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2342                                 # Old settings might have the title prefixed with
2343                                 # a colon for main-namespace pages
2344                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2345                                         $whitelisted = true;
2346                                 }
2347                         } elseif ( $this->isSpecialPage() ) {
2348                                 # If it's a special page, ditch the subpage bit and check again
2349                                 $name = $this->getDBkey();
2350                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2351                                 if ( $name ) {
2352                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2353                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2354                                                 $whitelisted = true;
2355                                         }
2356                                 }
2357                         }
2358                 }
2359
2360                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2361                         $name = $this->getPrefixedText();
2362                         // Check for regex whitelisting
2363                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2364                                 if ( preg_match( $listItem, $name ) ) {
2365                                         $whitelisted = true;
2366                                         break;
2367                                 }
2368                         }
2369                 }
2370
2371                 if ( !$whitelisted ) {
2372                         # If the title is not whitelisted, give extensions a chance to do so...
2373                         Hooks::run( 'TitleReadWhitelist', [ $this, $user, &$whitelisted ] );
2374                         if ( !$whitelisted ) {
2375                                 $errors[] = $this->missingPermissionError( $action, $short );
2376                         }
2377                 }
2378
2379                 return $errors;
2380         }
2381
2382         /**
2383          * Get a description array when the user doesn't have the right to perform
2384          * $action (i.e. when User::isAllowed() returns false)
2385          *
2386          * @param string $action The action to check
2387          * @param bool $short Short circuit on first error
2388          * @return array List of errors
2389          */
2390         private function missingPermissionError( $action, $short ) {
2391                 // We avoid expensive display logic for quickUserCan's and such
2392                 if ( $short ) {
2393                         return [ 'badaccess-group0' ];
2394                 }
2395
2396                 $groups = array_map( [ 'User', 'makeGroupLinkWiki' ],
2397                         User::getGroupsWithPermission( $action ) );
2398
2399                 if ( count( $groups ) ) {
2400                         global $wgLang;
2401                         return [
2402                                 'badaccess-groups',
2403                                 $wgLang->commaList( $groups ),
2404                                 count( $groups )
2405                         ];
2406                 } else {
2407                         return [ 'badaccess-group0' ];
2408                 }
2409         }
2410
2411         /**
2412          * Can $user perform $action on this page? This is an internal function,
2413          * with multiple levels of checks depending on performance needs; see $rigor below.
2414          * It does not check wfReadOnly().
2415          *
2416          * @param string $action Action that permission needs to be checked for
2417          * @param User $user User to check
2418          * @param string $rigor One of (quick,full,secure)
2419          *   - quick  : does cheap permission checks from replica DBs (usable for GUI creation)
2420          *   - full   : does cheap and expensive checks possibly from a replica DB
2421          *   - secure : does cheap and expensive checks, using the master as needed
2422          * @param bool $short Set this to true to stop after the first permission error.
2423          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2424          */
2425         protected function getUserPermissionsErrorsInternal(
2426                 $action, $user, $rigor = 'secure', $short = false
2427         ) {
2428                 if ( $rigor === true ) {
2429                         $rigor = 'secure'; // b/c
2430                 } elseif ( $rigor === false ) {
2431                         $rigor = 'quick'; // b/c
2432                 } elseif ( !in_array( $rigor, [ 'quick', 'full', 'secure' ] ) ) {
2433                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2434                 }
2435
2436                 # Read has special handling
2437                 if ( $action == 'read' ) {
2438                         $checks = [
2439                                 'checkPermissionHooks',
2440                                 'checkReadPermissions',
2441                                 'checkUserBlock', // for wgBlockDisablesLogin
2442                         ];
2443                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2444                 # here as it will lead to duplicate error messages. This is okay to do
2445                 # since anywhere that checks for create will also check for edit, and
2446                 # those checks are called for edit.
2447                 } elseif ( $action == 'create' ) {
2448                         $checks = [
2449                                 'checkQuickPermissions',
2450                                 'checkPermissionHooks',
2451                                 'checkPageRestrictions',
2452                                 'checkCascadingSourcesRestrictions',
2453                                 'checkActionPermissions',
2454                                 'checkUserBlock'
2455                         ];
2456                 } else {
2457                         $checks = [
2458                                 'checkQuickPermissions',
2459                                 'checkPermissionHooks',
2460                                 'checkSpecialsAndNSPermissions',
2461                                 'checkCSSandJSPermissions',
2462                                 'checkPageRestrictions',
2463                                 'checkCascadingSourcesRestrictions',
2464                                 'checkActionPermissions',
2465                                 'checkUserBlock'
2466                         ];
2467                 }
2468
2469                 $errors = [];
2470                 while ( count( $checks ) > 0 &&
2471                                 !( $short && count( $errors ) > 0 ) ) {
2472                         $method = array_shift( $checks );
2473                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2474                 }
2475
2476                 return $errors;
2477         }
2478
2479         /**
2480          * Get a filtered list of all restriction types supported by this wiki.
2481          * @param bool $exists True to get all restriction types that apply to
2482          * titles that do exist, False for all restriction types that apply to
2483          * titles that do not exist
2484          * @return array
2485          */
2486         public static function getFilteredRestrictionTypes( $exists = true ) {
2487                 global $wgRestrictionTypes;
2488                 $types = $wgRestrictionTypes;
2489                 if ( $exists ) {
2490                         # Remove the create restriction for existing titles
2491                         $types = array_diff( $types, [ 'create' ] );
2492                 } else {
2493                         # Only the create and upload restrictions apply to non-existing titles
2494                         $types = array_intersect( $types, [ 'create', 'upload' ] );
2495                 }
2496                 return $types;
2497         }
2498
2499         /**
2500          * Returns restriction types for the current Title
2501          *
2502          * @return array Applicable restriction types
2503          */
2504         public function getRestrictionTypes() {
2505                 if ( $this->isSpecialPage() ) {
2506                         return [];
2507                 }
2508
2509                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2510
2511                 if ( $this->getNamespace() != NS_FILE ) {
2512                         # Remove the upload restriction for non-file titles
2513                         $types = array_diff( $types, [ 'upload' ] );
2514                 }
2515
2516                 Hooks::run( 'TitleGetRestrictionTypes', [ $this, &$types ] );
2517
2518                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2519                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2520
2521                 return $types;
2522         }
2523
2524         /**
2525          * Is this title subject to title protection?
2526          * Title protection is the one applied against creation of such title.
2527          *
2528          * @return array|bool An associative array representing any existent title
2529          *   protection, or false if there's none.
2530          */
2531         public function getTitleProtection() {
2532                 // Can't protect pages in special namespaces
2533                 if ( $this->getNamespace() < 0 ) {
2534                         return false;
2535                 }
2536
2537                 // Can't protect pages that exist.
2538                 if ( $this->exists() ) {
2539                         return false;
2540                 }
2541
2542                 if ( $this->mTitleProtection === null ) {
2543                         $dbr = wfGetDB( DB_REPLICA );
2544                         $res = $dbr->select(
2545                                 'protected_titles',
2546                                 [
2547                                         'user' => 'pt_user',
2548                                         'reason' => 'pt_reason',
2549                                         'expiry' => 'pt_expiry',
2550                                         'permission' => 'pt_create_perm'
2551                                 ],
2552                                 [ 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ],
2553                                 __METHOD__
2554                         );
2555
2556                         // fetchRow returns false if there are no rows.
2557                         $row = $dbr->fetchRow( $res );
2558                         if ( $row ) {
2559                                 if ( $row['permission'] == 'sysop' ) {
2560                                         $row['permission'] = 'editprotected'; // B/C
2561                                 }
2562                                 if ( $row['permission'] == 'autoconfirmed' ) {
2563                                         $row['permission'] = 'editsemiprotected'; // B/C
2564                                 }
2565                                 $row['expiry'] = $dbr->decodeExpiry( $row['expiry'] );
2566                         }
2567                         $this->mTitleProtection = $row;
2568                 }
2569                 return $this->mTitleProtection;
2570         }
2571
2572         /**
2573          * Remove any title protection due to page existing
2574          */
2575         public function deleteTitleProtection() {
2576                 $dbw = wfGetDB( DB_MASTER );
2577
2578                 $dbw->delete(
2579                         'protected_titles',
2580                         [ 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ],
2581                         __METHOD__
2582                 );
2583                 $this->mTitleProtection = false;
2584         }
2585
2586         /**
2587          * Is this page "semi-protected" - the *only* protection levels are listed
2588          * in $wgSemiprotectedRestrictionLevels?
2589          *
2590          * @param string $action Action to check (default: edit)
2591          * @return bool
2592          */
2593         public function isSemiProtected( $action = 'edit' ) {
2594                 global $wgSemiprotectedRestrictionLevels;
2595
2596                 $restrictions = $this->getRestrictions( $action );
2597                 $semi = $wgSemiprotectedRestrictionLevels;
2598                 if ( !$restrictions || !$semi ) {
2599                         // Not protected, or all protection is full protection
2600                         return false;
2601                 }
2602
2603                 // Remap autoconfirmed to editsemiprotected for BC
2604                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2605                         $semi[$key] = 'editsemiprotected';
2606                 }
2607                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2608                         $restrictions[$key] = 'editsemiprotected';
2609                 }
2610
2611                 return !array_diff( $restrictions, $semi );
2612         }
2613
2614         /**
2615          * Does the title correspond to a protected article?
2616          *
2617          * @param string $action The action the page is protected from,
2618          * by default checks all actions.
2619          * @return bool
2620          */
2621         public function isProtected( $action = '' ) {
2622                 global $wgRestrictionLevels;
2623
2624                 $restrictionTypes = $this->getRestrictionTypes();
2625
2626                 # Special pages have inherent protection
2627                 if ( $this->isSpecialPage() ) {
2628                         return true;
2629                 }
2630
2631                 # Check regular protection levels
2632                 foreach ( $restrictionTypes as $type ) {
2633                         if ( $action == $type || $action == '' ) {
2634                                 $r = $this->getRestrictions( $type );
2635                                 foreach ( $wgRestrictionLevels as $level ) {
2636                                         if ( in_array( $level, $r ) && $level != '' ) {
2637                                                 return true;
2638                                         }
2639                                 }
2640                         }
2641                 }
2642
2643                 return false;
2644         }
2645
2646         /**
2647          * Determines if $user is unable to edit this page because it has been protected
2648          * by $wgNamespaceProtection.
2649          *
2650          * @param User $user User object to check permissions
2651          * @return bool
2652          */
2653         public function isNamespaceProtected( User $user ) {
2654                 global $wgNamespaceProtection;
2655
2656                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2657                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2658                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2659                                         return true;
2660                                 }
2661                         }
2662                 }
2663                 return false;
2664         }
2665
2666         /**
2667          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2668          *
2669          * @return bool If the page is subject to cascading restrictions.
2670          */
2671         public function isCascadeProtected() {
2672                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2673                 return ( $sources > 0 );
2674         }
2675
2676         /**
2677          * Determines whether cascading protection sources have already been loaded from
2678          * the database.
2679          *
2680          * @param bool $getPages True to check if the pages are loaded, or false to check
2681          * if the status is loaded.
2682          * @return bool Whether or not the specified information has been loaded
2683          * @since 1.23
2684          */
2685         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2686                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2687         }
2688
2689         /**
2690          * Cascading protection: Get the source of any cascading restrictions on this page.
2691          *
2692          * @param bool $getPages Whether or not to retrieve the actual pages
2693          *        that the restrictions have come from and the actual restrictions
2694          *        themselves.
2695          * @return array Two elements: First is an array of Title objects of the
2696          *        pages from which cascading restrictions have come, false for
2697          *        none, or true if such restrictions exist but $getPages was not
2698          *        set. Second is an array like that returned by
2699          *        Title::getAllRestrictions(), or an empty array if $getPages is
2700          *        false.
2701          */
2702         public function getCascadeProtectionSources( $getPages = true ) {
2703                 $pagerestrictions = [];
2704
2705                 if ( $this->mCascadeSources !== null && $getPages ) {
2706                         return [ $this->mCascadeSources, $this->mCascadingRestrictions ];
2707                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2708                         return [ $this->mHasCascadingRestrictions, $pagerestrictions ];
2709                 }
2710
2711                 $dbr = wfGetDB( DB_REPLICA );
2712
2713                 if ( $this->getNamespace() == NS_FILE ) {
2714                         $tables = [ 'imagelinks', 'page_restrictions' ];
2715                         $where_clauses = [
2716                                 'il_to' => $this->getDBkey(),
2717                                 'il_from=pr_page',
2718                                 'pr_cascade' => 1
2719                         ];
2720                 } else {
2721                         $tables = [ 'templatelinks', 'page_restrictions' ];
2722                         $where_clauses = [
2723                                 'tl_namespace' => $this->getNamespace(),
2724                                 'tl_title' => $this->getDBkey(),
2725                                 'tl_from=pr_page',
2726                                 'pr_cascade' => 1
2727                         ];
2728                 }
2729
2730                 if ( $getPages ) {
2731                         $cols = [ 'pr_page', 'page_namespace', 'page_title',
2732                                 'pr_expiry', 'pr_type', 'pr_level' ];
2733                         $where_clauses[] = 'page_id=pr_page';
2734                         $tables[] = 'page';
2735                 } else {
2736                         $cols = [ 'pr_expiry' ];
2737                 }
2738
2739                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2740
2741                 $sources = $getPages ? [] : false;
2742                 $now = wfTimestampNow();
2743
2744                 foreach ( $res as $row ) {
2745                         $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2746                         if ( $expiry > $now ) {
2747                                 if ( $getPages ) {
2748                                         $page_id = $row->pr_page;
2749                                         $page_ns = $row->page_namespace;
2750                                         $page_title = $row->page_title;
2751                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2752                                         # Add groups needed for each restriction type if its not already there
2753                                         # Make sure this restriction type still exists
2754
2755                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2756                                                 $pagerestrictions[$row->pr_type] = [];
2757                                         }
2758
2759                                         if (
2760                                                 isset( $pagerestrictions[$row->pr_type] )
2761                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2762                                         ) {
2763                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2764                                         }
2765                                 } else {
2766                                         $sources = true;
2767                                 }
2768                         }
2769                 }
2770
2771                 if ( $getPages ) {
2772                         $this->mCascadeSources = $sources;
2773                         $this->mCascadingRestrictions = $pagerestrictions;
2774                 } else {
2775                         $this->mHasCascadingRestrictions = $sources;
2776                 }
2777
2778                 return [ $sources, $pagerestrictions ];
2779         }
2780
2781         /**
2782          * Accessor for mRestrictionsLoaded
2783          *
2784          * @return bool Whether or not the page's restrictions have already been
2785          * loaded from the database
2786          * @since 1.23
2787          */
2788         public function areRestrictionsLoaded() {
2789                 return $this->mRestrictionsLoaded;
2790         }
2791
2792         /**
2793          * Accessor/initialisation for mRestrictions
2794          *
2795          * @param string $action Action that permission needs to be checked for
2796          * @return array Restriction levels needed to take the action. All levels are
2797          *     required. Note that restriction levels are normally user rights, but 'sysop'
2798          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2799          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2800          */
2801         public function getRestrictions( $action ) {
2802                 if ( !$this->mRestrictionsLoaded ) {
2803                         $this->loadRestrictions();
2804                 }
2805                 return isset( $this->mRestrictions[$action] )
2806                                 ? $this->mRestrictions[$action]
2807                                 : [];
2808         }
2809
2810         /**
2811          * Accessor/initialisation for mRestrictions
2812          *
2813          * @return array Keys are actions, values are arrays as returned by
2814          *     Title::getRestrictions()
2815          * @since 1.23
2816          */
2817         public function getAllRestrictions() {
2818                 if ( !$this->mRestrictionsLoaded ) {
2819                         $this->loadRestrictions();
2820                 }
2821                 return $this->mRestrictions;
2822         }
2823
2824         /**
2825          * Get the expiry time for the restriction against a given action
2826          *
2827          * @param string $action
2828          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2829          *     or not protected at all, or false if the action is not recognised.
2830          */
2831         public function getRestrictionExpiry( $action ) {
2832                 if ( !$this->mRestrictionsLoaded ) {
2833                         $this->loadRestrictions();
2834                 }
2835                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2836         }
2837
2838         /**
2839          * Returns cascading restrictions for the current article
2840          *
2841          * @return bool
2842          */
2843         function areRestrictionsCascading() {
2844                 if ( !$this->mRestrictionsLoaded ) {
2845                         $this->loadRestrictions();
2846                 }
2847
2848                 return $this->mCascadeRestriction;
2849         }
2850
2851         /**
2852          * Compiles list of active page restrictions from both page table (pre 1.10)
2853          * and page_restrictions table for this existing page.
2854          * Public for usage by LiquidThreads.
2855          *
2856          * @param array $rows Array of db result objects
2857          * @param string $oldFashionedRestrictions Comma-separated list of page
2858          *   restrictions from page table (pre 1.10)
2859          */
2860         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2861                 $dbr = wfGetDB( DB_REPLICA );
2862
2863                 $restrictionTypes = $this->getRestrictionTypes();
2864
2865                 foreach ( $restrictionTypes as $type ) {
2866                         $this->mRestrictions[$type] = [];
2867                         $this->mRestrictionsExpiry[$type] = 'infinity';
2868                 }
2869
2870                 $this->mCascadeRestriction = false;
2871
2872                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2873                 if ( $oldFashionedRestrictions !== null ) {
2874                         $this->mOldRestrictions = $oldFashionedRestrictions;
2875                 }
2876
2877                 if ( $this->mOldRestrictions === false ) {
2878                         $this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2879                                 [ 'page_id' => $this->getArticleID() ], __METHOD__ );
2880                 }
2881
2882                 if ( $this->mOldRestrictions != '' ) {
2883                         foreach ( explode( ':', trim( $this->mOldRestrictions ) ) as $restrict ) {
2884                                 $temp = explode( '=', trim( $restrict ) );
2885                                 if ( count( $temp ) == 1 ) {
2886                                         // old old format should be treated as edit/move restriction
2887                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2888                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2889                                 } else {
2890                                         $restriction = trim( $temp[1] );
2891                                         if ( $restriction != '' ) { // some old entries are empty
2892                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2893                                         }
2894                                 }
2895                         }
2896                 }
2897
2898                 if ( count( $rows ) ) {
2899                         # Current system - load second to make them override.
2900                         $now = wfTimestampNow();
2901
2902                         # Cycle through all the restrictions.
2903                         foreach ( $rows as $row ) {
2904
2905                                 // Don't take care of restrictions types that aren't allowed
2906                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2907                                         continue;
2908                                 }
2909
2910                                 // This code should be refactored, now that it's being used more generally,
2911                                 // But I don't really see any harm in leaving it in Block for now -werdna
2912                                 $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2913
2914                                 // Only apply the restrictions if they haven't expired!
2915                                 if ( !$expiry || $expiry > $now ) {
2916                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2917                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2918
2919                                         $this->mCascadeRestriction |= $row->pr_cascade;
2920                                 }
2921                         }
2922                 }
2923
2924                 $this->mRestrictionsLoaded = true;
2925         }
2926
2927         /**
2928          * Load restrictions from the page_restrictions table
2929          *
2930          * @param string $oldFashionedRestrictions Comma-separated list of page
2931          *   restrictions from page table (pre 1.10)
2932          */
2933         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2934                 if ( $this->mRestrictionsLoaded ) {
2935                         return;
2936                 }
2937
2938                 $id = $this->getArticleID();
2939                 if ( $id ) {
2940                         $cache = ObjectCache::getMainWANInstance();
2941                         $rows = $cache->getWithSetCallback(
2942                                 // Page protections always leave a new null revision
2943                                 $cache->makeKey( 'page-restrictions', $id, $this->getLatestRevID() ),
2944                                 $cache::TTL_DAY,
2945                                 function ( $curValue, &$ttl, array &$setOpts ) {
2946                                         $dbr = wfGetDB( DB_REPLICA );
2947
2948                                         $setOpts += Database::getCacheSetOptions( $dbr );
2949
2950                                         return iterator_to_array(
2951                                                 $dbr->select(
2952                                                         'page_restrictions',
2953                                                         [ 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ],
2954                                                         [ 'pr_page' => $this->getArticleID() ],
2955                                                         __METHOD__
2956                                                 )
2957                                         );
2958                                 }
2959                         );
2960
2961                         $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2962                 } else {
2963                         $title_protection = $this->getTitleProtection();
2964
2965                         if ( $title_protection ) {
2966                                 $now = wfTimestampNow();
2967                                 $expiry = wfGetDB( DB_REPLICA )->decodeExpiry( $title_protection['expiry'] );
2968
2969                                 if ( !$expiry || $expiry > $now ) {
2970                                         // Apply the restrictions
2971                                         $this->mRestrictionsExpiry['create'] = $expiry;
2972                                         $this->mRestrictions['create'] =
2973                                                 explode( ',', trim( $title_protection['permission'] ) );
2974                                 } else { // Get rid of the old restrictions
2975                                         $this->mTitleProtection = false;
2976                                 }
2977                         } else {
2978                                 $this->mRestrictionsExpiry['create'] = 'infinity';
2979                         }
2980                         $this->mRestrictionsLoaded = true;
2981                 }
2982         }
2983
2984         /**
2985          * Flush the protection cache in this object and force reload from the database.
2986          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2987          */
2988         public function flushRestrictions() {
2989                 $this->mRestrictionsLoaded = false;
2990                 $this->mTitleProtection = null;
2991         }
2992
2993         /**
2994          * Purge expired restrictions from the page_restrictions table
2995          *
2996          * This will purge no more than $wgUpdateRowsPerQuery page_restrictions rows
2997          */
2998         static function purgeExpiredRestrictions() {
2999                 if ( wfReadOnly() ) {
3000                         return;
3001                 }
3002
3003                 DeferredUpdates::addUpdate( new AtomicSectionUpdate(
3004                         wfGetDB( DB_MASTER ),
3005                         __METHOD__,
3006                         function ( IDatabase $dbw, $fname ) {
3007                                 $config = MediaWikiServices::getInstance()->getMainConfig();
3008                                 $ids = $dbw->selectFieldValues(
3009                                         'page_restrictions',
3010                                         'pr_id',
3011                                         [ 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ],
3012                                         $fname,
3013                                         [ 'LIMIT' => $config->get( 'UpdateRowsPerQuery' ) ] // T135470
3014                                 );
3015                                 if ( $ids ) {
3016                                         $dbw->delete( 'page_restrictions', [ 'pr_id' => $ids ], $fname );
3017                                 }
3018                         }
3019                 ) );
3020
3021                 DeferredUpdates::addUpdate( new AtomicSectionUpdate(
3022                         wfGetDB( DB_MASTER ),
3023                         __METHOD__,
3024                         function ( IDatabase $dbw, $fname ) {
3025                                 $dbw->delete(
3026                                         'protected_titles',
3027                                         [ 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ],
3028                                         $fname
3029                                 );
3030                         }
3031                 ) );
3032         }
3033
3034         /**
3035          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3036          *
3037          * @return bool
3038          */
3039         public function hasSubpages() {
3040                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3041                         # Duh
3042                         return false;
3043                 }
3044
3045                 # We dynamically add a member variable for the purpose of this method
3046                 # alone to cache the result.  There's no point in having it hanging
3047                 # around uninitialized in every Title object; therefore we only add it
3048                 # if needed and don't declare it statically.
3049                 if ( $this->mHasSubpages === null ) {
3050                         $this->mHasSubpages = false;
3051                         $subpages = $this->getSubpages( 1 );
3052                         if ( $subpages instanceof TitleArray ) {
3053                                 $this->mHasSubpages = (bool)$subpages->count();
3054                         }
3055                 }
3056
3057                 return $this->mHasSubpages;
3058         }
3059
3060         /**
3061          * Get all subpages of this page.
3062          *
3063          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3064          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3065          *  doesn't allow subpages
3066          */
3067         public function getSubpages( $limit = -1 ) {
3068                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3069                         return [];
3070                 }
3071
3072                 $dbr = wfGetDB( DB_REPLICA );
3073                 $conds['page_namespace'] = $this->getNamespace();
3074                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3075                 $options = [];
3076                 if ( $limit > -1 ) {
3077                         $options['LIMIT'] = $limit;
3078                 }
3079                 $this->mSubpages = TitleArray::newFromResult(
3080                         $dbr->select( 'page',
3081                                 [ 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ],
3082                                 $conds,
3083                                 __METHOD__,
3084                                 $options
3085                         )
3086                 );
3087                 return $this->mSubpages;
3088         }
3089
3090         /**
3091          * Is there a version of this page in the deletion archive?
3092          *
3093          * @return int The number of archived revisions
3094          */
3095         public function isDeleted() {
3096                 if ( $this->getNamespace() < 0 ) {
3097                         $n = 0;
3098                 } else {
3099                         $dbr = wfGetDB( DB_REPLICA );
3100
3101                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3102                                 [ 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ],
3103                                 __METHOD__
3104                         );
3105                         if ( $this->getNamespace() == NS_FILE ) {
3106                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3107                                         [ 'fa_name' => $this->getDBkey() ],
3108                                         __METHOD__
3109                                 );
3110                         }
3111                 }
3112                 return (int)$n;
3113         }
3114
3115         /**
3116          * Is there a version of this page in the deletion archive?
3117          *
3118          * @return bool
3119          */
3120         public function isDeletedQuick() {
3121                 if ( $this->getNamespace() < 0 ) {
3122                         return false;
3123                 }
3124                 $dbr = wfGetDB( DB_REPLICA );
3125                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3126                         [ 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ],
3127                         __METHOD__
3128                 );
3129                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3130                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3131                                 [ 'fa_name' => $this->getDBkey() ],
3132                                 __METHOD__
3133                         );
3134                 }
3135                 return $deleted;
3136         }
3137
3138         /**
3139          * Get the article ID for this Title from the link cache,
3140          * adding it if necessary
3141          *
3142          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3143          *  for update
3144          * @return int The ID
3145          */
3146         public function getArticleID( $flags = 0 ) {
3147                 if ( $this->getNamespace() < 0 ) {
3148                         $this->mArticleID = 0;
3149                         return $this->mArticleID;
3150                 }
3151                 $linkCache = LinkCache::singleton();
3152                 if ( $flags & self::GAID_FOR_UPDATE ) {
3153                         $oldUpdate = $linkCache->forUpdate( true );
3154                         $linkCache->clearLink( $this );
3155                         $this->mArticleID = $linkCache->addLinkObj( $this );
3156                         $linkCache->forUpdate( $oldUpdate );
3157                 } else {
3158                         if ( -1 == $this->mArticleID ) {
3159                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3160                         }
3161                 }
3162                 return $this->mArticleID;
3163         }
3164
3165         /**
3166          * Is this an article that is a redirect page?
3167          * Uses link cache, adding it if necessary
3168          *
3169          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3170          * @return bool
3171          */
3172         public function isRedirect( $flags = 0 ) {
3173                 if ( !is_null( $this->mRedirect ) ) {
3174                         return $this->mRedirect;
3175                 }
3176                 if ( !$this->getArticleID( $flags ) ) {
3177                         $this->mRedirect = false;
3178                         return $this->mRedirect;
3179                 }
3180
3181                 $linkCache = LinkCache::singleton();
3182                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3183                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3184                 if ( $cached === null ) {
3185                         # Trust LinkCache's state over our own
3186                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3187                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3188                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3189                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3190                         # LinkCache to refresh its data from the master.
3191                         $this->mRedirect = false;
3192                         return $this->mRedirect;
3193                 }
3194
3195                 $this->mRedirect = (bool)$cached;
3196
3197                 return $this->mRedirect;
3198         }
3199
3200         /**
3201          * What is the length of this page?
3202          * Uses link cache, adding it if necessary
3203          *
3204          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3205          * @return int
3206          */
3207         public function getLength( $flags = 0 ) {
3208                 if ( $this->mLength != -1 ) {
3209                         return $this->mLength;
3210                 }
3211                 if ( !$this->getArticleID( $flags ) ) {
3212                         $this->mLength = 0;
3213                         return $this->mLength;
3214                 }
3215                 $linkCache = LinkCache::singleton();
3216                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3217                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3218                 if ( $cached === null ) {
3219                         # Trust LinkCache's state over our own, as for isRedirect()
3220                         $this->mLength = 0;
3221                         return $this->mLength;
3222                 }
3223
3224                 $this->mLength = intval( $cached );
3225
3226                 return $this->mLength;
3227         }
3228
3229         /**
3230          * What is the page_latest field for this page?
3231          *
3232          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3233          * @return int Int or 0 if the page doesn't exist
3234          */
3235         public function getLatestRevID( $flags = 0 ) {
3236                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3237                         return intval( $this->mLatestID );
3238                 }
3239                 if ( !$this->getArticleID( $flags ) ) {
3240                         $this->mLatestID = 0;
3241                         return $this->mLatestID;
3242                 }
3243                 $linkCache = LinkCache::singleton();
3244                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3245                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3246                 if ( $cached === null ) {
3247                         # Trust LinkCache's state over our own, as for isRedirect()
3248                         $this->mLatestID = 0;
3249                         return $this->mLatestID;
3250                 }
3251
3252                 $this->mLatestID = intval( $cached );
3253
3254                 return $this->mLatestID;
3255         }
3256
3257         /**
3258          * This clears some fields in this object, and clears any associated
3259          * keys in the "bad links" section of the link cache.
3260          *
3261          * - This is called from WikiPage::doEditContent() and WikiPage::insertOn() to allow
3262          * loading of the new page_id. It's also called from
3263          * WikiPage::doDeleteArticleReal()
3264          *
3265          * @param int $newid The new Article ID
3266          */
3267         public function resetArticleID( $newid ) {
3268                 $linkCache = LinkCache::singleton();
3269                 $linkCache->clearLink( $this );
3270
3271                 if ( $newid === false ) {
3272                         $this->mArticleID = -1;
3273                 } else {
3274                         $this->mArticleID = intval( $newid );
3275                 }
3276                 $this->mRestrictionsLoaded = false;
3277                 $this->mRestrictions = [];
3278                 $this->mOldRestrictions = false;
3279                 $this->mRedirect = null;
3280                 $this->mLength = -1;
3281                 $this->mLatestID = false;
3282                 $this->mContentModel = false;
3283                 $this->mEstimateRevisions = null;
3284                 $this->mPageLanguage = false;
3285                 $this->mDbPageLanguage = false;
3286                 $this->mIsBigDeletion = null;
3287         }
3288
3289         public static function clearCaches() {
3290                 $linkCache = LinkCache::singleton();
3291                 $linkCache->clear();
3292
3293                 $titleCache = self::getTitleCache();
3294                 $titleCache->clear();
3295         }
3296
3297         /**
3298          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3299          *
3300          * @param string $text Containing title to capitalize
3301          * @param int $ns Namespace index, defaults to NS_MAIN
3302          * @return string Containing capitalized title
3303          */
3304         public static function capitalize( $text, $ns = NS_MAIN ) {
3305                 global $wgContLang;
3306
3307                 if ( MWNamespace::isCapitalized( $ns ) ) {
3308                         return $wgContLang->ucfirst( $text );
3309                 } else {
3310                         return $text;
3311                 }
3312         }
3313
3314         /**
3315          * Secure and split - main initialisation function for this object
3316          *
3317          * Assumes that mDbkeyform has been set, and is urldecoded
3318          * and uses underscores, but not otherwise munged.  This function
3319          * removes illegal characters, splits off the interwiki and
3320          * namespace prefixes, sets the other forms, and canonicalizes
3321          * everything.
3322          *
3323          * @throws MalformedTitleException On invalid titles
3324          * @return bool True on success
3325          */
3326         private function secureAndSplit() {
3327                 # Initialisation
3328                 $this->mInterwiki = '';
3329                 $this->mFragment = '';
3330                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3331
3332                 $dbkey = $this->mDbkeyform;
3333
3334                 // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3335                 //        the parsing code with Title, while avoiding massive refactoring.
3336                 // @todo: get rid of secureAndSplit, refactor parsing code.
3337                 // @note: getTitleParser() returns a TitleParser implementation which does not have a
3338                 //        splitTitleString method, but the only implementation (MediaWikiTitleCodec) does
3339                 $titleCodec = MediaWikiServices::getInstance()->getTitleParser();
3340                 // MalformedTitleException can be thrown here
3341                 $parts = $titleCodec->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3342
3343                 # Fill fields
3344                 $this->setFragment( '#' . $parts['fragment'] );
3345                 $this->mInterwiki = $parts['interwiki'];
3346                 $this->mLocalInterwiki = $parts['local_interwiki'];
3347                 $this->mNamespace = $parts['namespace'];
3348                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3349
3350                 $this->mDbkeyform = $parts['dbkey'];
3351                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3352                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
3353
3354                 # We already know that some pages won't be in the database!
3355                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3356                         $this->mArticleID = 0;
3357                 }
3358
3359                 return true;
3360         }
3361
3362         /**
3363          * Get an array of Title objects linking to this Title
3364          * Also stores the IDs in the link cache.
3365          *
3366          * WARNING: do not use this function on arbitrary user-supplied titles!
3367          * On heavily-used templates it will max out the memory.
3368          *
3369          * @param array $options May be FOR UPDATE
3370          * @param string $table Table name
3371          * @param string $prefix Fields prefix
3372          * @return Title[] Array of Title objects linking here
3373          */
3374         public function getLinksTo( $options = [], $table = 'pagelinks', $prefix = 'pl' ) {
3375                 if ( count( $options ) > 0 ) {
3376                         $db = wfGetDB( DB_MASTER );
3377                 } else {
3378                         $db = wfGetDB( DB_REPLICA );
3379                 }
3380
3381                 $res = $db->select(
3382                         [ 'page', $table ],
3383                         self::getSelectFields(),
3384                         [
3385                                 "{$prefix}_from=page_id",
3386                                 "{$prefix}_namespace" => $this->getNamespace(),
3387                                 "{$prefix}_title" => $this->getDBkey() ],
3388                         __METHOD__,
3389                         $options
3390                 );
3391
3392                 $retVal = [];
3393                 if ( $res->numRows() ) {
3394                         $linkCache = LinkCache::singleton();
3395                         foreach ( $res as $row ) {
3396                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3397                                 if ( $titleObj ) {
3398                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3399                                         $retVal[] = $titleObj;
3400                                 }
3401                         }
3402                 }
3403                 return $retVal;
3404         }
3405
3406         /**
3407          * Get an array of Title objects using this Title as a template
3408          * Also stores the IDs in the link cache.
3409          *
3410          * WARNING: do not use this function on arbitrary user-supplied titles!
3411          * On heavily-used templates it will max out the memory.
3412          *
3413          * @param array $options Query option to Database::select()
3414          * @return Title[] Array of Title the Title objects linking here
3415          */
3416         public function getTemplateLinksTo( $options = [] ) {
3417                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3418         }
3419
3420         /**
3421          * Get an array of Title objects linked from this Title
3422          * Also stores the IDs in the link cache.
3423          *
3424          * WARNING: do not use this function on arbitrary user-supplied titles!
3425          * On heavily-used templates it will max out the memory.
3426          *
3427          * @param array $options Query option to Database::select()
3428          * @param string $table Table name
3429          * @param string $prefix Fields prefix
3430          * @return array Array of Title objects linking here
3431          */
3432         public function getLinksFrom( $options = [], $table = 'pagelinks', $prefix = 'pl' ) {
3433                 $id = $this->getArticleID();
3434
3435                 # If the page doesn't exist; there can't be any link from this page
3436                 if ( !$id ) {
3437                         return [];
3438                 }
3439
3440                 $db = wfGetDB( DB_REPLICA );
3441
3442                 $blNamespace = "{$prefix}_namespace";
3443                 $blTitle = "{$prefix}_title";
3444
3445                 $res = $db->select(
3446                         [ $table, 'page' ],
3447                         array_merge(
3448                                 [ $blNamespace, $blTitle ],
3449                                 WikiPage::selectFields()
3450                         ),
3451                         [ "{$prefix}_from" => $id ],
3452                         __METHOD__,
3453                         $options,
3454                         [ 'page' => [
3455                                 'LEFT JOIN',
3456                                 [ "page_namespace=$blNamespace", "page_title=$blTitle" ]
3457                         ] ]
3458                 );
3459
3460                 $retVal = [];
3461                 $linkCache = LinkCache::singleton();
3462                 foreach ( $res as $row ) {
3463                         if ( $row->page_id ) {
3464                                 $titleObj = Title::newFromRow( $row );
3465                         } else {
3466                                 $titleObj = Title::makeTitle( $row->$blNamespace, $row->$blTitle );
3467                                 $linkCache->addBadLinkObj( $titleObj );
3468                         }
3469                         $retVal[] = $titleObj;
3470                 }
3471
3472                 return $retVal;
3473         }
3474
3475         /**
3476          * Get an array of Title objects used on this Title as a template
3477          * Also stores the IDs in the link cache.
3478          *
3479          * WARNING: do not use this function on arbitrary user-supplied titles!
3480          * On heavily-used templates it will max out the memory.
3481          *
3482          * @param array $options May be FOR UPDATE
3483          * @return Title[] Array of Title the Title objects used here
3484          */
3485         public function getTemplateLinksFrom( $options = [] ) {
3486                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3487         }
3488
3489         /**
3490          * Get an array of Title objects referring to non-existent articles linked
3491          * from this page.
3492          *
3493          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3494          *   should use redirect table in this case).
3495          * @return Title[] Array of Title the Title objects
3496          */
3497         public function getBrokenLinksFrom() {
3498                 if ( $this->getArticleID() == 0 ) {
3499                         # All links from article ID 0 are false positives
3500                         return [];
3501                 }
3502
3503                 $dbr = wfGetDB( DB_REPLICA );
3504                 $res = $dbr->select(
3505                         [ 'page', 'pagelinks' ],
3506                         [ 'pl_namespace', 'pl_title' ],
3507                         [
3508                                 'pl_from' => $this->getArticleID(),
3509                                 'page_namespace IS NULL'
3510                         ],
3511                         __METHOD__, [],
3512                         [
3513                                 'page' => [
3514                                         'LEFT JOIN',
3515                                         [ 'pl_namespace=page_namespace', 'pl_title=page_title' ]
3516                                 ]
3517                         ]
3518                 );
3519
3520                 $retVal = [];
3521                 foreach ( $res as $row ) {
3522                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3523                 }
3524                 return $retVal;
3525         }
3526
3527         /**
3528          * Get a list of URLs to purge from the CDN cache when this
3529          * page changes
3530          *
3531          * @return string[] Array of String the URLs
3532          */
3533         public function getCdnUrls() {
3534                 $urls = [
3535                         $this->getInternalURL(),
3536                         $this->getInternalURL( 'action=history' )
3537                 ];
3538
3539                 $pageLang = $this->getPageLanguage();
3540                 if ( $pageLang->hasVariants() ) {
3541                         $variants = $pageLang->getVariants();
3542                         foreach ( $variants as $vCode ) {
3543                                 $urls[] = $this->getInternalURL( $vCode );
3544                         }
3545                 }
3546
3547                 // If we are looking at a css/js user subpage, purge the action=raw.
3548                 if ( $this->isJsSubpage() ) {
3549                         $urls[] = $this->getInternalURL( 'action=raw&ctype=text/javascript' );
3550                 } elseif ( $this->isCssSubpage() ) {
3551                         $urls[] = $this->getInternalURL( 'action=raw&ctype=text/css' );
3552                 }
3553
3554                 Hooks::run( 'TitleSquidURLs', [ $this, &$urls ] );
3555                 return $urls;
3556         }
3557
3558         /**
3559          * @deprecated since 1.27 use getCdnUrls()
3560          */
3561         public function getSquidURLs() {
3562                 return $this->getCdnUrls();
3563         }
3564
3565         /**
3566          * Purge all applicable CDN URLs
3567          */
3568         public function purgeSquid() {
3569                 DeferredUpdates::addUpdate(
3570                         new CdnCacheUpdate( $this->getCdnUrls() ),
3571                         DeferredUpdates::PRESEND
3572                 );
3573         }
3574
3575         /**
3576          * Move this page without authentication
3577          *
3578          * @deprecated since 1.25 use MovePage class instead
3579          * @param Title $nt The new page Title
3580          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3581          */
3582         public function moveNoAuth( &$nt ) {
3583                 wfDeprecated( __METHOD__, '1.25' );
3584                 return $this->moveTo( $nt, false );
3585         }
3586
3587         /**
3588          * Check whether a given move operation would be valid.
3589          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3590          *
3591          * @deprecated since 1.25, use MovePage's methods instead
3592          * @param Title $nt The new title
3593          * @param bool $auth Whether to check user permissions (uses $wgUser)
3594          * @param string $reason Is the log summary of the move, used for spam checking
3595          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3596          */
3597         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3598                 global $wgUser;
3599
3600                 if ( !( $nt instanceof Title ) ) {
3601                         // Normally we'd add this to $errors, but we'll get
3602                         // lots of syntax errors if $nt is not an object
3603                         return [ [ 'badtitletext' ] ];
3604                 }
3605
3606                 $mp = new MovePage( $this, $nt );
3607                 $errors = $mp->isValidMove()->getErrorsArray();
3608                 if ( $auth ) {
3609                         $errors = wfMergeErrorArrays(
3610                                 $errors,
3611                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3612                         );
3613                 }
3614
3615                 return $errors ?: true;
3616         }
3617
3618         /**
3619          * Check if the requested move target is a valid file move target
3620          * @todo move this to MovePage
3621          * @param Title $nt Target title
3622          * @return array List of errors
3623          */
3624         protected function validateFileMoveOperation( $nt ) {
3625                 global $wgUser;
3626
3627                 $errors = [];
3628
3629                 $destFile = wfLocalFile( $nt );
3630                 $destFile->load( File::READ_LATEST );
3631                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3632                         && !$destFile->exists() && wfFindFile( $nt )
3633                 ) {
3634                         $errors[] = [ 'file-exists-sharedrepo' ];
3635                 }
3636
3637                 return $errors;
3638         }
3639
3640         /**
3641          * Move a title to a new location
3642          *
3643          * @deprecated since 1.25, use the MovePage class instead
3644          * @param Title $nt The new title
3645          * @param bool $auth Indicates whether $wgUser's permissions
3646          *  should be checked
3647          * @param string $reason The reason for the move
3648          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3649          *  Ignored if the user doesn't have the suppressredirect right.
3650          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3651          */
3652         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3653                 global $wgUser;
3654                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3655                 if ( is_array( $err ) ) {
3656                         // Auto-block user's IP if the account was "hard" blocked
3657                         $wgUser->spreadAnyEditBlock();
3658                         return $err;
3659                 }
3660                 // Check suppressredirect permission
3661                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3662                         $createRedirect = true;
3663                 }
3664
3665                 $mp = new MovePage( $this, $nt );
3666                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3667                 if ( $status->isOK() ) {
3668                         return true;
3669                 } else {
3670                         return $status->getErrorsArray();
3671                 }
3672         }
3673
3674         /**
3675          * Move this page's subpages to be subpages of $nt
3676          *
3677          * @param Title $nt Move target
3678          * @param bool $auth Whether $wgUser's permissions should be checked
3679          * @param string $reason The reason for the move
3680          * @param bool $createRedirect Whether to create redirects from the old subpages to
3681          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3682          * @return array Array with old page titles as keys, and strings (new page titles) or
3683          *     arrays (errors) as values, or an error array with numeric indices if no pages
3684          *     were moved
3685          */
3686         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3687                 global $wgMaximumMovedPages;
3688                 // Check permissions
3689                 if ( !$this->userCan( 'move-subpages' ) ) {
3690                         return [ 'cant-move-subpages' ];
3691                 }
3692                 // Do the source and target namespaces support subpages?
3693                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3694                         return [ 'namespace-nosubpages',
3695                                 MWNamespace::getCanonicalName( $this->getNamespace() ) ];
3696                 }
3697                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3698                         return [ 'namespace-nosubpages',
3699                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) ];
3700                 }
3701
3702                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3703                 $retval = [];
3704                 $count = 0;
3705                 foreach ( $subpages as $oldSubpage ) {
3706                         $count++;
3707                         if ( $count > $wgMaximumMovedPages ) {
3708                                 $retval[$oldSubpage->getPrefixedText()] =
3709                                                 [ 'movepage-max-pages',
3710                                                         $wgMaximumMovedPages ];
3711                                 break;
3712                         }
3713
3714                         // We don't know whether this function was called before
3715                         // or after moving the root page, so check both
3716                         // $this and $nt
3717                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3718                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3719                         ) {
3720                                 // When moving a page to a subpage of itself,
3721                                 // don't move it twice
3722                                 continue;
3723                         }
3724                         $newPageName = preg_replace(
3725                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3726                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3727                                         $oldSubpage->getDBkey() );
3728                         if ( $oldSubpage->isTalkPage() ) {
3729                                 $newNs = $nt->getTalkPage()->getNamespace();
3730                         } else {
3731                                 $newNs = $nt->getSubjectPage()->getNamespace();
3732                         }
3733                         # Bug 14385: we need makeTitleSafe because the new page names may
3734                         # be longer than 255 characters.
3735                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3736
3737                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3738                         if ( $success === true ) {
3739                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3740                         } else {
3741                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3742                         }
3743                 }
3744                 return $retval;
3745         }
3746
3747         /**
3748          * Checks if this page is just a one-rev redirect.
3749          * Adds lock, so don't use just for light purposes.
3750          *
3751          * @return bool
3752          */
3753         public function isSingleRevRedirect() {
3754                 global $wgContentHandlerUseDB;
3755
3756                 $dbw = wfGetDB( DB_MASTER );
3757
3758                 # Is it a redirect?
3759                 $fields = [ 'page_is_redirect', 'page_latest', 'page_id' ];
3760                 if ( $wgContentHandlerUseDB ) {
3761                         $fields[] = 'page_content_model';
3762                 }
3763
3764                 $row = $dbw->selectRow( 'page',
3765                         $fields,
3766                         $this->pageCond(),
3767                         __METHOD__,
3768                         [ 'FOR UPDATE' ]
3769                 );
3770                 # Cache some fields we may want
3771                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3772                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3773                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3774                 $this->mContentModel = $row && isset( $row->page_content_model )
3775                         ? strval( $row->page_content_model )
3776                         : false;
3777
3778                 if ( !$this->mRedirect ) {
3779                         return false;
3780                 }
3781                 # Does the article have a history?
3782                 $row = $dbw->selectField( [ 'page', 'revision' ],
3783                         'rev_id',
3784                         [ 'page_namespace' => $this->getNamespace(),
3785                                 'page_title' => $this->getDBkey(),
3786                                 'page_id=rev_page',
3787                                 'page_latest != rev_id'
3788                         ],
3789                         __METHOD__,
3790                         [ 'FOR UPDATE' ]
3791                 );
3792                 # Return true if there was no history
3793                 return ( $row === false );
3794         }
3795
3796         /**
3797          * Checks if $this can be moved to a given Title
3798          * - Selects for update, so don't call it unless you mean business
3799          *
3800          * @deprecated since 1.25, use MovePage's methods instead
3801          * @param Title $nt The new title to check
3802          * @return bool
3803          */
3804         public function isValidMoveTarget( $nt ) {
3805                 # Is it an existing file?
3806                 if ( $nt->getNamespace() == NS_FILE ) {
3807                         $file = wfLocalFile( $nt );
3808                         $file->load( File::READ_LATEST );
3809                         if ( $file->exists() ) {
3810                                 wfDebug( __METHOD__ . ": file exists\n" );
3811                                 return false;
3812                         }
3813                 }
3814                 # Is it a redirect with no history?
3815                 if ( !$nt->isSingleRevRedirect() ) {
3816                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3817                         return false;
3818                 }
3819                 # Get the article text
3820                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3821                 if ( !is_object( $rev ) ) {
3822                         return false;
3823                 }
3824                 $content = $rev->getContent();
3825                 # Does the redirect point to the source?
3826                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3827                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3828
3829                 if ( $redirTitle ) {
3830                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3831                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3832                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3833                                 return false;
3834                         } else {
3835                                 return true;
3836                         }
3837                 } else {
3838                         # Fail safe (not a redirect after all. strange.)
3839                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3840                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3841                         return false;
3842                 }
3843         }
3844
3845         /**
3846          * Get categories to which this Title belongs and return an array of
3847          * categories' names.
3848          *
3849          * @return array Array of parents in the form:
3850          *        $parent => $currentarticle
3851          */
3852         public function getParentCategories() {
3853                 global $wgContLang;
3854
3855                 $data = [];
3856
3857                 $titleKey = $this->getArticleID();
3858
3859                 if ( $titleKey === 0 ) {
3860                         return $data;
3861                 }
3862
3863                 $dbr = wfGetDB( DB_REPLICA );
3864
3865                 $res = $dbr->select(
3866                         'categorylinks',
3867                         'cl_to',
3868                         [ 'cl_from' => $titleKey ],
3869                         __METHOD__
3870                 );
3871
3872                 if ( $res->numRows() > 0 ) {
3873                         foreach ( $res as $row ) {
3874                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3875                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3876                         }
3877                 }
3878                 return $data;
3879         }
3880
3881         /**
3882          * Get a tree of parent categories
3883          *
3884          * @param array $children Array with the children in the keys, to check for circular refs
3885          * @return array Tree of parent categories
3886          */
3887         public function getParentCategoryTree( $children = [] ) {
3888                 $stack = [];
3889                 $parents = $this->getParentCategories();
3890
3891                 if ( $parents ) {
3892                         foreach ( $parents as $parent => $current ) {
3893                                 if ( array_key_exists( $parent, $children ) ) {
3894                                         # Circular reference
3895                                         $stack[$parent] = [];
3896                                 } else {
3897                                         $nt = Title::newFromText( $parent );
3898                                         if ( $nt ) {
3899                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + [ $parent => 1 ] );
3900                                         }
3901                                 }
3902                         }
3903                 }
3904
3905                 return $stack;
3906         }
3907
3908         /**
3909          * Get an associative array for selecting this title from
3910          * the "page" table
3911          *
3912          * @return array Array suitable for the $where parameter of DB::select()
3913          */
3914         public function pageCond() {
3915                 if ( $this->mArticleID > 0 ) {
3916                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3917                         return [ 'page_id' => $this->mArticleID ];
3918                 } else {
3919                         return [ 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform ];
3920                 }
3921         }
3922
3923         /**
3924          * Get the revision ID of the previous revision
3925          *
3926          * @param int $revId Revision ID. Get the revision that was before this one.
3927          * @param int $flags Title::GAID_FOR_UPDATE
3928          * @return int|bool Old revision ID, or false if none exists
3929          */
3930         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3931                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_REPLICA );
3932                 $revId = $db->selectField( 'revision', 'rev_id',
3933                         [
3934                                 'rev_page' => $this->getArticleID( $flags ),
3935                                 'rev_id < ' . intval( $revId )
3936                         ],
3937                         __METHOD__,
3938                         [ 'ORDER BY' => 'rev_id DESC' ]
3939                 );
3940
3941                 if ( $revId === false ) {
3942                         return false;
3943                 } else {
3944                         return intval( $revId );
3945                 }
3946         }
3947
3948         /**
3949          * Get the revision ID of the next revision
3950          *
3951          * @param int $revId Revision ID. Get the revision that was after this one.
3952          * @param int $flags Title::GAID_FOR_UPDATE
3953          * @return int|bool Next revision ID, or false if none exists
3954          */
3955         public function getNextRevisionID( $revId, $flags = 0 ) {
3956                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_REPLICA );
3957                 $revId = $db->selectField( 'revision', 'rev_id',
3958                         [
3959                                 'rev_page' => $this->getArticleID( $flags ),
3960                                 'rev_id > ' . intval( $revId )
3961                         ],
3962                         __METHOD__,
3963                         [ 'ORDER BY' => 'rev_id' ]
3964                 );
3965
3966                 if ( $revId === false ) {
3967                         return false;
3968                 } else {
3969                         return intval( $revId );
3970                 }
3971         }
3972
3973         /**
3974          * Get the first revision of the page
3975          *
3976          * @param int $flags Title::GAID_FOR_UPDATE
3977          * @return Revision|null If page doesn't exist
3978          */
3979         public function getFirstRevision( $flags = 0 ) {
3980                 $pageId = $this->getArticleID( $flags );
3981                 if ( $pageId ) {
3982                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_REPLICA );
3983                         $row = $db->selectRow( 'revision', Revision::selectFields(),
3984                                 [ 'rev_page' => $pageId ],
3985                                 __METHOD__,
3986                                 [ 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 ]
3987                         );
3988                         if ( $row ) {
3989                                 return new Revision( $row );
3990                         }
3991                 }
3992                 return null;
3993         }
3994
3995         /**
3996          * Get the oldest revision timestamp of this page
3997          *
3998          * @param int $flags Title::GAID_FOR_UPDATE
3999          * @return string MW timestamp
4000          */
4001         public function getEarliestRevTime( $flags = 0 ) {
4002                 $rev = $this->getFirstRevision( $flags );
4003                 return $rev ? $rev->getTimestamp() : null;
4004         }
4005
4006         /**
4007          * Check if this is a new page
4008          *
4009          * @return bool
4010          */
4011         public function isNewPage() {
4012                 $dbr = wfGetDB( DB_REPLICA );
4013                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4014         }
4015
4016         /**
4017          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4018          *
4019          * @return bool
4020          */
4021         public function isBigDeletion() {
4022                 global $wgDeleteRevisionsLimit;
4023
4024                 if ( !$wgDeleteRevisionsLimit ) {
4025                         return false;
4026                 }
4027
4028                 if ( $this->mIsBigDeletion === null ) {
4029                         $dbr = wfGetDB( DB_REPLICA );
4030
4031                         $revCount = $dbr->selectRowCount(
4032                                 'revision',
4033                                 '1',
4034                                 [ 'rev_page' => $this->getArticleID() ],
4035                                 __METHOD__,
4036                                 [ 'LIMIT' => $wgDeleteRevisionsLimit + 1 ]
4037                         );
4038
4039                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4040                 }
4041
4042                 return $this->mIsBigDeletion;
4043         }
4044
4045         /**
4046          * Get the approximate revision count of this page.
4047          *
4048          * @return int
4049          */
4050         public function estimateRevisionCount() {
4051                 if ( !$this->exists() ) {
4052                         return 0;
4053                 }
4054
4055                 if ( $this->mEstimateRevisions === null ) {
4056                         $dbr = wfGetDB( DB_REPLICA );
4057                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4058                                 [ 'rev_page' => $this->getArticleID() ], __METHOD__ );
4059                 }
4060
4061                 return $this->mEstimateRevisions;
4062         }
4063
4064         /**
4065          * Get the number of revisions between the given revision.
4066          * Used for diffs and other things that really need it.
4067          *
4068          * @param int|Revision $old Old revision or rev ID (first before range)
4069          * @param int|Revision $new New revision or rev ID (first after range)
4070          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4071          * @return int Number of revisions between these revisions.
4072          */
4073         public function countRevisionsBetween( $old, $new, $max = null ) {
4074                 if ( !( $old instanceof Revision ) ) {
4075                         $old = Revision::newFromTitle( $this, (int)$old );
4076                 }
4077                 if ( !( $new instanceof Revision ) ) {
4078                         $new = Revision::newFromTitle( $this, (int)$new );
4079                 }
4080                 if ( !$old || !$new ) {
4081                         return 0; // nothing to compare
4082                 }
4083                 $dbr = wfGetDB( DB_REPLICA );
4084                 $conds = [
4085                         'rev_page' => $this->getArticleID(),
4086                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4087                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4088                 ];
4089                 if ( $max !== null ) {
4090                         return $dbr->selectRowCount( 'revision', '1',
4091                                 $conds,
4092                                 __METHOD__,
4093                                 [ 'LIMIT' => $max + 1 ] // extra to detect truncation
4094                         );
4095                 } else {
4096                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4097                 }
4098         }
4099
4100         /**
4101          * Get the authors between the given revisions or revision IDs.
4102          * Used for diffs and other things that really need it.
4103          *
4104          * @since 1.23
4105          *
4106          * @param int|Revision $old Old revision or rev ID (first before range by default)
4107          * @param int|Revision $new New revision or rev ID (first after range by default)
4108          * @param int $limit Maximum number of authors
4109          * @param string|array $options (Optional): Single option, or an array of options:
4110          *     'include_old' Include $old in the range; $new is excluded.
4111          *     'include_new' Include $new in the range; $old is excluded.
4112          *     'include_both' Include both $old and $new in the range.
4113          *     Unknown option values are ignored.
4114          * @return array|null Names of revision authors in the range; null if not both revisions exist
4115          */
4116         public function getAuthorsBetween( $old, $new, $limit, $options = [] ) {
4117                 if ( !( $old instanceof Revision ) ) {
4118                         $old = Revision::newFromTitle( $this, (int)$old );
4119                 }
4120                 if ( !( $new instanceof Revision ) ) {
4121                         $new = Revision::newFromTitle( $this, (int)$new );
4122                 }
4123                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4124                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4125                 // in the sanity check below?
4126                 if ( !$old || !$new ) {
4127                         return null; // nothing to compare
4128                 }
4129                 $authors = [];
4130                 $old_cmp = '>';
4131                 $new_cmp = '<';
4132                 $options = (array)$options;
4133                 if ( in_array( 'include_old', $options ) ) {
4134                         $old_cmp = '>=';
4135                 }
4136                 if ( in_array( 'include_new', $options ) ) {
4137                         $new_cmp = '<=';
4138                 }
4139                 if ( in_array( 'include_both', $options ) ) {
4140                         $old_cmp = '>=';
4141                         $new_cmp = '<=';
4142                 }
4143                 // No DB query needed if $old and $new are the same or successive revisions:
4144                 if ( $old->getId() === $new->getId() ) {
4145                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4146                                 [] :
4147                                 [ $old->getUserText( Revision::RAW ) ];
4148                 } elseif ( $old->getId() === $new->getParentId() ) {
4149                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4150                                 $authors[] = $old->getUserText( Revision::RAW );
4151                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4152                                         $authors[] = $new->getUserText( Revision::RAW );
4153                                 }
4154                         } elseif ( $old_cmp === '>=' ) {
4155                                 $authors[] = $old->getUserText( Revision::RAW );
4156                         } elseif ( $new_cmp === '<=' ) {
4157                                 $authors[] = $new->getUserText( Revision::RAW );
4158                         }
4159                         return $authors;
4160                 }
4161                 $dbr = wfGetDB( DB_REPLICA );
4162                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4163                         [
4164                                 'rev_page' => $this->getArticleID(),
4165                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4166                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4167                         ], __METHOD__,
4168                         [ 'LIMIT' => $limit + 1 ] // add one so caller knows it was truncated
4169                 );
4170                 foreach ( $res as $row ) {
4171                         $authors[] = $row->rev_user_text;
4172                 }
4173                 return $authors;
4174         }
4175
4176         /**
4177          * Get the number of authors between the given revisions or revision IDs.
4178          * Used for diffs and other things that really need it.
4179          *
4180          * @param int|Revision $old Old revision or rev ID (first before range by default)
4181          * @param int|Revision $new New revision or rev ID (first after range by default)
4182          * @param int $limit Maximum number of authors
4183          * @param string|array $options (Optional): Single option, or an array of options:
4184          *     'include_old' Include $old in the range; $new is excluded.
4185          *     'include_new' Include $new in the range; $old is excluded.
4186          *     'include_both' Include both $old and $new in the range.
4187          *     Unknown option values are ignored.
4188          * @return int Number of revision authors in the range; zero if not both revisions exist
4189          */
4190         public function countAuthorsBetween( $old, $new, $limit, $options = [] ) {
4191                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4192                 return $authors ? count( $authors ) : 0;
4193         }
4194
4195         /**
4196          * Compare with another title.
4197          *
4198          * @param Title $title
4199          * @return bool
4200          */
4201         public function equals( Title $title ) {
4202                 // Note: === is necessary for proper matching of number-like titles.
4203                 return $this->getInterwiki() === $title->getInterwiki()
4204                         && $this->getNamespace() == $title->getNamespace()
4205                         && $this->getDBkey() === $title->getDBkey();
4206         }
4207
4208         /**
4209          * Check if this title is a subpage of another title
4210          *
4211          * @param Title $title
4212          * @return bool
4213          */
4214         public function isSubpageOf( Title $title ) {
4215                 return $this->getInterwiki() === $title->getInterwiki()
4216                         && $this->getNamespace() == $title->getNamespace()
4217                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4218         }
4219
4220         /**
4221          * Check if page exists.  For historical reasons, this function simply
4222          * checks for the existence of the title in the page table, and will
4223          * thus return false for interwiki links, special pages and the like.
4224          * If you want to know if a title can be meaningfully viewed, you should
4225          * probably call the isKnown() method instead.
4226          *
4227          * @param int $flags An optional bit field; may be Title::GAID_FOR_UPDATE to check
4228          *   from master/for update
4229          * @return bool
4230          */
4231         public function exists( $flags = 0 ) {
4232                 $exists = $this->getArticleID( $flags ) != 0;
4233                 Hooks::run( 'TitleExists', [ $this, &$exists ] );
4234                 return $exists;
4235         }
4236
4237         /**
4238          * Should links to this title be shown as potentially viewable (i.e. as
4239          * "bluelinks"), even if there's no record by this title in the page
4240          * table?
4241          *
4242          * This function is semi-deprecated for public use, as well as somewhat
4243          * misleadingly named.  You probably just want to call isKnown(), which
4244          * calls this function internally.
4245          *
4246          * (ISSUE: Most of these checks are cheap, but the file existence check
4247          * can potentially be quite expensive.  Including it here fixes a lot of
4248          * existing code, but we might want to add an optional parameter to skip
4249          * it and any other expensive checks.)
4250          *
4251          * @return bool
4252          */
4253         public function isAlwaysKnown() {
4254                 $isKnown = null;
4255
4256                 /**
4257                  * Allows overriding default behavior for determining if a page exists.
4258                  * If $isKnown is kept as null, regular checks happen. If it's
4259                  * a boolean, this value is returned by the isKnown method.
4260                  *
4261                  * @since 1.20
4262                  *
4263                  * @param Title $title
4264                  * @param bool|null $isKnown
4265                  */
4266                 Hooks::run( 'TitleIsAlwaysKnown', [ $this, &$isKnown ] );
4267
4268                 if ( !is_null( $isKnown ) ) {
4269                         return $isKnown;
4270                 }
4271
4272                 if ( $this->isExternal() ) {
4273                         return true;  // any interwiki link might be viewable, for all we know
4274                 }
4275
4276                 switch ( $this->mNamespace ) {
4277                         case NS_MEDIA:
4278                         case NS_FILE:
4279                                 // file exists, possibly in a foreign repo
4280                                 return (bool)wfFindFile( $this );
4281                         case NS_SPECIAL:
4282                                 // valid special page
4283                                 return SpecialPageFactory::exists( $this->getDBkey() );
4284                         case NS_MAIN:
4285                                 // selflink, possibly with fragment
4286                                 return $this->mDbkeyform == '';
4287                         case NS_MEDIAWIKI:
4288                                 // known system message
4289                                 return $this->hasSourceText() !== false;
4290                         default:
4291                                 return false;
4292                 }
4293         }
4294
4295         /**
4296          * Does this title refer to a page that can (or might) be meaningfully
4297          * viewed?  In particular, this function may be used to determine if
4298          * links to the title should be rendered as "bluelinks" (as opposed to
4299          * "redlinks" to non-existent pages).
4300          * Adding something else to this function will cause inconsistency
4301          * since LinkHolderArray calls isAlwaysKnown() and does its own
4302          * page existence check.
4303          *
4304          * @return bool
4305          */
4306         public function isKnown() {
4307                 return $this->isAlwaysKnown() || $this->exists();
4308         }
4309
4310         /**
4311          * Does this page have source text?
4312          *
4313          * @return bool
4314          */
4315         public function hasSourceText() {
4316                 if ( $this->exists() ) {
4317                         return true;
4318                 }
4319
4320                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4321                         // If the page doesn't exist but is a known system message, default
4322                         // message content will be displayed, same for language subpages-
4323                         // Use always content language to avoid loading hundreds of languages
4324                         // to get the link color.
4325                         global $wgContLang;
4326                         list( $name, ) = MessageCache::singleton()->figureMessage(
4327                                 $wgContLang->lcfirst( $this->getText() )
4328                         );
4329                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4330                         return $message->exists();
4331                 }
4332
4333                 return false;
4334         }
4335
4336         /**
4337          * Get the default message text or false if the message doesn't exist
4338          *
4339          * @return string|bool
4340          */
4341         public function getDefaultMessageText() {
4342                 global $wgContLang;
4343
4344                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4345                         return false;
4346                 }
4347
4348                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4349                         $wgContLang->lcfirst( $this->getText() )
4350                 );
4351                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4352
4353                 if ( $message->exists() ) {
4354                         return $message->plain();
4355                 } else {
4356                         return false;
4357                 }
4358         }
4359
4360         /**
4361          * Updates page_touched for this page; called from LinksUpdate.php
4362          *
4363          * @param string $purgeTime [optional] TS_MW timestamp
4364          * @return bool True if the update succeeded
4365          */
4366         public function invalidateCache( $purgeTime = null ) {
4367                 if ( wfReadOnly() ) {
4368                         return false;
4369                 }
4370
4371                 if ( $this->mArticleID === 0 ) {
4372                         return true; // avoid gap locking if we know it's not there
4373                 }
4374
4375                 $conds = $this->pageCond();
4376                 DeferredUpdates::addUpdate(
4377                         new AutoCommitUpdate(
4378                                 wfGetDB( DB_MASTER ),
4379                                 __METHOD__,
4380                                 function ( IDatabase $dbw, $fname ) use ( $conds, $purgeTime ) {
4381                                         $dbTimestamp = $dbw->timestamp( $purgeTime ?: time() );
4382                                         $dbw->update(
4383                                                 'page',
4384                                                 [ 'page_touched' => $dbTimestamp ],
4385                                                 $conds + [ 'page_touched < ' . $dbw->addQuotes( $dbTimestamp ) ],
4386                                                 $fname
4387                                         );
4388                                         MediaWikiServices::getInstance()->getLinkCache()->invalidateTitle( $this );
4389                                 }
4390                         ),
4391                         DeferredUpdates::PRESEND
4392                 );
4393
4394                 return true;
4395         }
4396
4397         /**
4398          * Update page_touched timestamps and send CDN purge messages for
4399          * pages linking to this title. May be sent to the job queue depending
4400          * on the number of links. Typically called on create and delete.
4401          */
4402         public function touchLinks() {
4403                 DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'pagelinks' ) );
4404                 if ( $this->getNamespace() == NS_CATEGORY ) {
4405                         DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'categorylinks' ) );
4406                 }
4407         }
4408
4409         /**
4410          * Get the last touched timestamp
4411          *
4412          * @param IDatabase $db Optional db
4413          * @return string Last-touched timestamp
4414          */
4415         public function getTouched( $db = null ) {
4416                 if ( $db === null ) {
4417                         $db = wfGetDB( DB_REPLICA );
4418                 }
4419                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4420                 return $touched;
4421         }
4422
4423         /**
4424          * Get the timestamp when this page was updated since the user last saw it.
4425          *
4426          * @param User $user
4427          * @return string|null
4428          */
4429         public function getNotificationTimestamp( $user = null ) {
4430                 global $wgUser;
4431
4432                 // Assume current user if none given
4433                 if ( !$user ) {
4434                         $user = $wgUser;
4435                 }
4436                 // Check cache first
4437                 $uid = $user->getId();
4438                 if ( !$uid ) {
4439                         return false;
4440                 }
4441                 // avoid isset here, as it'll return false for null entries
4442                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4443                         return $this->mNotificationTimestamp[$uid];
4444                 }
4445                 // Don't cache too much!
4446                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4447                         $this->mNotificationTimestamp = [];
4448                 }
4449
4450                 $store = MediaWikiServices::getInstance()->getWatchedItemStore();
4451                 $watchedItem = $store->getWatchedItem( $user, $this );
4452                 if ( $watchedItem ) {
4453                         $this->mNotificationTimestamp[$uid] = $watchedItem->getNotificationTimestamp();
4454                 } else {
4455                         $this->mNotificationTimestamp[$uid] = false;
4456                 }
4457
4458                 return $this->mNotificationTimestamp[$uid];
4459         }
4460
4461         /**
4462          * Generate strings used for xml 'id' names in monobook tabs
4463          *
4464          * @param string $prepend Defaults to 'nstab-'
4465          * @return string XML 'id' name
4466          */
4467         public function getNamespaceKey( $prepend = 'nstab-' ) {
4468                 global $wgContLang;
4469                 // Gets the subject namespace if this title
4470                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4471                 // Checks if canonical namespace name exists for namespace
4472                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4473                         // Uses canonical namespace name
4474                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4475                 } else {
4476                         // Uses text of namespace
4477                         $namespaceKey = $this->getSubjectNsText();
4478                 }
4479                 // Makes namespace key lowercase
4480                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4481                 // Uses main
4482                 if ( $namespaceKey == '' ) {
4483                         $namespaceKey = 'main';
4484                 }
4485                 // Changes file to image for backwards compatibility
4486                 if ( $namespaceKey == 'file' ) {
4487                         $namespaceKey = 'image';
4488                 }
4489                 return $prepend . $namespaceKey;
4490         }
4491
4492         /**
4493          * Get all extant redirects to this Title
4494          *
4495          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4496          * @return Title[] Array of Title redirects to this title
4497          */
4498         public function getRedirectsHere( $ns = null ) {
4499                 $redirs = [];
4500
4501                 $dbr = wfGetDB( DB_REPLICA );
4502                 $where = [
4503                         'rd_namespace' => $this->getNamespace(),
4504                         'rd_title' => $this->getDBkey(),
4505                         'rd_from = page_id'
4506                 ];
4507                 if ( $this->isExternal() ) {
4508                         $where['rd_interwiki'] = $this->getInterwiki();
4509                 } else {
4510                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4511                 }
4512                 if ( !is_null( $ns ) ) {
4513                         $where['page_namespace'] = $ns;
4514                 }
4515
4516                 $res = $dbr->select(
4517                         [ 'redirect', 'page' ],
4518                         [ 'page_namespace', 'page_title' ],
4519                         $where,
4520                         __METHOD__
4521                 );
4522
4523                 foreach ( $res as $row ) {
4524                         $redirs[] = self::newFromRow( $row );
4525                 }
4526                 return $redirs;
4527         }
4528
4529         /**
4530          * Check if this Title is a valid redirect target
4531          *
4532          * @return bool
4533          */
4534         public function isValidRedirectTarget() {
4535                 global $wgInvalidRedirectTargets;
4536
4537                 if ( $this->isSpecialPage() ) {
4538                         // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4539                         if ( $this->isSpecial( 'Userlogout' ) ) {
4540                                 return false;
4541                         }
4542
4543                         foreach ( $wgInvalidRedirectTargets as $target ) {
4544                                 if ( $this->isSpecial( $target ) ) {
4545                                         return false;
4546                                 }
4547                         }
4548                 }
4549
4550                 return true;
4551         }
4552
4553         /**
4554          * Get a backlink cache object
4555          *
4556          * @return BacklinkCache
4557          */
4558         public function getBacklinkCache() {
4559                 return BacklinkCache::get( $this );
4560         }
4561
4562         /**
4563          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4564          *
4565          * @return bool
4566          */
4567         public function canUseNoindex() {
4568                 global $wgExemptFromUserRobotsControl;
4569
4570                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4571                         ? MWNamespace::getContentNamespaces()
4572                         : $wgExemptFromUserRobotsControl;
4573
4574                 return !in_array( $this->mNamespace, $bannedNamespaces );
4575
4576         }
4577
4578         /**
4579          * Returns the raw sort key to be used for categories, with the specified
4580          * prefix.  This will be fed to Collation::getSortKey() to get a
4581          * binary sortkey that can be used for actual sorting.
4582          *
4583          * @param string $prefix The prefix to be used, specified using
4584          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4585          *   prefix.
4586          * @return string
4587          */
4588         public function getCategorySortkey( $prefix = '' ) {
4589                 $unprefixed = $this->getText();
4590
4591                 // Anything that uses this hook should only depend
4592                 // on the Title object passed in, and should probably
4593                 // tell the users to run updateCollations.php --force
4594                 // in order to re-sort existing category relations.
4595                 Hooks::run( 'GetDefaultSortkey', [ $this, &$unprefixed ] );
4596                 if ( $prefix !== '' ) {
4597                         # Separate with a line feed, so the unprefixed part is only used as
4598                         # a tiebreaker when two pages have the exact same prefix.
4599                         # In UCA, tab is the only character that can sort above LF
4600                         # so we strip both of them from the original prefix.
4601                         $prefix = strtr( $prefix, "\n\t", '  ' );
4602                         return "$prefix\n$unprefixed";
4603                 }
4604                 return $unprefixed;
4605         }
4606
4607         /**
4608          * Returns the page language code saved in the database, if $wgPageLanguageUseDB is set
4609          * to true in LocalSettings.php, otherwise returns false. If there is no language saved in
4610          * the db, it will return NULL.
4611          *
4612          * @return string|null|bool
4613          */
4614         private function getDbPageLanguageCode() {
4615                 global $wgPageLanguageUseDB;
4616
4617                 // check, if the page language could be saved in the database, and if so and
4618                 // the value is not requested already, lookup the page language using LinkCache
4619                 if ( $wgPageLanguageUseDB && $this->mDbPageLanguage === false ) {
4620                         $linkCache = LinkCache::singleton();
4621                         $linkCache->addLinkObj( $this );
4622                         $this->mDbPageLanguage = $linkCache->getGoodLinkFieldObj( $this, 'lang' );
4623                 }
4624
4625                 return $this->mDbPageLanguage;
4626         }
4627
4628         /**
4629          * Get the language in which the content of this page is written in
4630          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4631          * e.g. $wgLang (such as special pages, which are in the user language).
4632          *
4633          * @since 1.18
4634          * @return Language
4635          */
4636         public function getPageLanguage() {
4637                 global $wgLang, $wgLanguageCode;
4638                 if ( $this->isSpecialPage() ) {
4639                         // special pages are in the user language
4640                         return $wgLang;
4641                 }
4642
4643                 // Checking if DB language is set
4644                 $dbPageLanguage = $this->getDbPageLanguageCode();
4645                 if ( $dbPageLanguage ) {
4646                         return wfGetLangObj( $dbPageLanguage );
4647                 }
4648
4649                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4650                         // Note that this may depend on user settings, so the cache should
4651                         // be only per-request.
4652                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4653                         // content to determine the page language!
4654                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4655                         // tests.
4656                         $contentHandler = ContentHandler::getForTitle( $this );
4657                         $langObj = $contentHandler->getPageLanguage( $this );
4658                         $this->mPageLanguage = [ $langObj->getCode(), $wgLanguageCode ];
4659                 } else {
4660                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4661                 }
4662
4663                 return $langObj;
4664         }
4665
4666         /**
4667          * Get the language in which the content of this page is written when
4668          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4669          * e.g. $wgLang (such as special pages, which are in the user language).
4670          *
4671          * @since 1.20
4672          * @return Language
4673          */
4674         public function getPageViewLanguage() {
4675                 global $wgLang;
4676
4677                 if ( $this->isSpecialPage() ) {
4678                         // If the user chooses a variant, the content is actually
4679                         // in a language whose code is the variant code.
4680                         $variant = $wgLang->getPreferredVariant();
4681                         if ( $wgLang->getCode() !== $variant ) {
4682                                 return Language::factory( $variant );
4683                         }
4684
4685                         return $wgLang;
4686                 }
4687
4688                 // Checking if DB language is set
4689                 $dbPageLanguage = $this->getDbPageLanguageCode();
4690                 if ( $dbPageLanguage ) {
4691                         $pageLang = wfGetLangObj( $dbPageLanguage );
4692                         $variant = $pageLang->getPreferredVariant();
4693                         if ( $pageLang->getCode() !== $variant ) {
4694                                 $pageLang = Language::factory( $variant );
4695                         }
4696
4697                         return $pageLang;
4698                 }
4699
4700                 // @note Can't be cached persistently, depends on user settings.
4701                 // @note ContentHandler::getPageViewLanguage() may need to load the
4702                 //   content to determine the page language!
4703                 $contentHandler = ContentHandler::getForTitle( $this );
4704                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4705                 return $pageLang;
4706         }
4707
4708         /**
4709          * Get a list of rendered edit notices for this page.
4710          *
4711          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4712          * they will already be wrapped in paragraphs.
4713          *
4714          * @since 1.21
4715          * @param int $oldid Revision ID that's being edited
4716          * @return array
4717          */
4718         public function getEditNotices( $oldid = 0 ) {
4719                 $notices = [];
4720
4721                 // Optional notice for the entire namespace
4722                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4723                 $msg = wfMessage( $editnotice_ns );
4724                 if ( $msg->exists() ) {
4725                         $html = $msg->parseAsBlock();
4726                         // Edit notices may have complex logic, but output nothing (T91715)
4727                         if ( trim( $html ) !== '' ) {
4728                                 $notices[$editnotice_ns] = Html::rawElement(
4729                                         'div',
4730                                         [ 'class' => [
4731                                                 'mw-editnotice',
4732                                                 'mw-editnotice-namespace',
4733                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4734                                         ] ],
4735                                         $html
4736                                 );
4737                         }
4738                 }
4739
4740                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4741                         // Optional notice for page itself and any parent page
4742                         $parts = explode( '/', $this->getDBkey() );
4743                         $editnotice_base = $editnotice_ns;
4744                         while ( count( $parts ) > 0 ) {
4745                                 $editnotice_base .= '-' . array_shift( $parts );
4746                                 $msg = wfMessage( $editnotice_base );
4747                                 if ( $msg->exists() ) {
4748                                         $html = $msg->parseAsBlock();
4749                                         if ( trim( $html ) !== '' ) {
4750                                                 $notices[$editnotice_base] = Html::rawElement(
4751                                                         'div',
4752                                                         [ 'class' => [
4753                                                                 'mw-editnotice',
4754                                                                 'mw-editnotice-base',
4755                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4756                                                         ] ],
4757                                                         $html
4758                                                 );
4759                                         }
4760                                 }
4761                         }
4762                 } else {
4763                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4764                         $editnoticeText = $editnotice_ns . '-' . strtr( $this->getDBkey(), '/', '-' );
4765                         $msg = wfMessage( $editnoticeText );
4766                         if ( $msg->exists() ) {
4767                                 $html = $msg->parseAsBlock();
4768                                 if ( trim( $html ) !== '' ) {
4769                                         $notices[$editnoticeText] = Html::rawElement(
4770                                                 'div',
4771                                                 [ 'class' => [
4772                                                         'mw-editnotice',
4773                                                         'mw-editnotice-page',
4774                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4775                                                 ] ],
4776                                                 $html
4777                                         );
4778                                 }
4779                         }
4780                 }
4781
4782                 Hooks::run( 'TitleGetEditNotices', [ $this, $oldid, &$notices ] );
4783                 return $notices;
4784         }
4785
4786         /**
4787          * @return array
4788          */
4789         public function __sleep() {
4790                 return [
4791                         'mNamespace',
4792                         'mDbkeyform',
4793                         'mFragment',
4794                         'mInterwiki',
4795                         'mLocalInterwiki',
4796                         'mUserCaseDBKey',
4797                         'mDefaultNamespace',
4798                 ];
4799         }
4800
4801         public function __wakeup() {
4802                 $this->mArticleID = ( $this->mNamespace >= 0 ) ? -1 : 0;
4803                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
4804                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
4805         }
4806
4807 }