includes/Title.php

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