includes/Title.php

   1 <?php
   2 /**
   3  * Representation of a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  * @note Consider using a TitleValue object instead. TitleValue is more lightweight
  31  *       and does not rely on global state or the database.
  32  */
  33 class Title implements LinkTarget {
  34         /** @var HashBagOStuff */
  35         static private $titleCache = null;
  36
  37         /**
  38          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  39          * commonly used titles. On a batch operation this can become a memory leak
  40          * if not bounded. After hitting this many titles reset the cache.
  41          */
  42         const CACHE_MAX = 1000;
  43
  44         /**
  45          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  46          * to use the master DB
  47          */
  48         const GAID_FOR_UPDATE = 1;
  49
  50         /**
  51          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         /** @var string Text form (spaces not underscores) of the main part */
  58         public $mTextform = '';
  59
  60         /** @var string URL-encoded form of the main part */
  61         public $mUrlform = '';
  62
  63         /** @var string Main part with underscores */
  64         public $mDbkeyform = '';
  65
  66         /** @var string Database key with the initial letter in the case specified by the user */
  67         protected $mUserCaseDBKey;
  68
  69         /** @var int Namespace index, i.e. one of the NS_xxxx constants */
  70         public $mNamespace = NS_MAIN;
  71
  72         /** @var string Interwiki prefix */
  73         public $mInterwiki = '';
  74
  75         /** @var bool Was this Title created from a string with a local interwiki prefix? */
  76         private $mLocalInterwiki = false;
  77
  78         /** @var string Title fragment (i.e. the bit after the #) */
  79         public $mFragment = '';
  80
  81         /** @var int Article ID, fetched from the link cache on demand */
  82         public $mArticleID = -1;
  83
  84         /** @var bool|int ID of most recent revision */
  85         protected $mLatestID = false;
  86
  87         /**
  88          * @var bool|string ID of the page's content model, i.e. one of the
  89          *   CONTENT_MODEL_XXX constants
  90          */
  91         public $mContentModel = false;
  92
  93         /** @var int Estimated number of revisions; null of not loaded */
  94         private $mEstimateRevisions;
  95
  96         /** @var array Array of groups allowed to edit this article */
  97         public $mRestrictions = [];
  98
  99         /** @var string|bool */
 100         protected $mOldRestrictions = false;
 101
 102         /** @var bool Cascade restrictions on this page to included templates and images? */
 103         public $mCascadeRestriction;
 104
 105         /** Caching the results of getCascadeProtectionSources */
 106         public $mCascadingRestrictions;
 107
 108         /** @var array When do the restrictions on this page expire? */
 109         protected $mRestrictionsExpiry = [];
 110
 111         /** @var bool Are cascading restrictions in effect on this page? */
 112         protected $mHasCascadingRestrictions;
 113
 114         /** @var array Where are the cascading restrictions coming from on this page? */
 115         public $mCascadeSources;
 116
 117         /** @var bool Boolean for initialisation on demand */
 118         public $mRestrictionsLoaded = false;
 119
 120         /** @var string Text form including namespace/interwiki, initialised on demand */
 121         protected $mPrefixedText = null;
 122
 123         /** @var mixed Cached value for getTitleProtection (create protection) */
 124         public $mTitleProtection;
 125
 126         /**
 127          * @var int Namespace index when there is no namespace. Don't change the
 128          *   following default, NS_MAIN is hardcoded in several places. See bug 696.
 129          *   Zero except in {{transclusion}} tags.
 130          */
 131         public $mDefaultNamespace = NS_MAIN;
 132
 133         /** @var int The page length, 0 for special pages */
 134         protected $mLength = -1;
 135
 136         /** @var null Is the article at this title a redirect? */
 137         public $mRedirect = null;
 138
 139         /** @var array Associative array of user ID -> timestamp/false */
 140         private $mNotificationTimestamp = [];
 141
 142         /** @var bool Whether a page has any subpages */
 143         private $mHasSubpages;
 144
 145         /** @var bool The (string) language code of the page's language and content code. */
 146         private $mPageLanguage = false;
 147
 148         /** @var string|bool|null The page language code from the database, null if not saved in
 149          * the database or false if not loaded, yet. */
 150         private $mDbPageLanguage = false;
 151
 152         /** @var TitleValue A corresponding TitleValue object */
 153         private $mTitleValue = null;
 154
 155         /** @var bool Would deleting this page be a big deletion? */
 156         private $mIsBigDeletion = null;
 157         // @}
 158
 159         /**
 160          * B/C kludge: provide a TitleParser for use by Title.
 161          * Ideally, Title would have no methods that need this.
 162          * Avoid usage of this singleton by using TitleValue
 163          * and the associated services when possible.
 164          *
 165          * @return MediaWikiTitleCodec
 166          */
 167         private static function getMediaWikiTitleCodec() {
 168                 global $wgContLang, $wgLocalInterwikis;
 169
 170                 static $titleCodec = null;
 171                 static $titleCodecFingerprint = null;
 172
 173                 // $wgContLang and $wgLocalInterwikis may change (especially while testing),
 174                 // make sure we are using the right one. To detect changes over the course
 175                 // of a request, we remember a fingerprint of the config used to create the
 176                 // codec singleton, and re-create it if the fingerprint doesn't match.
 177                 $fingerprint = spl_object_hash( $wgContLang ) . '|' . implode( '+', $wgLocalInterwikis );
 178
 179                 if ( $fingerprint !== $titleCodecFingerprint ) {
 180                         $titleCodec = null;
 181                 }
 182
 183                 if ( !$titleCodec ) {
 184                         $titleCodec = new MediaWikiTitleCodec(
 185                                 $wgContLang,
 186                                 GenderCache::singleton(),
 187                                 $wgLocalInterwikis
 188                         );
 189                         $titleCodecFingerprint = $fingerprint;
 190                 }
 191
 192                 return $titleCodec;
 193         }
 194
 195         /**
 196          * B/C kludge: provide a TitleParser for use by Title.
 197          * Ideally, Title would have no methods that need this.
 198          * Avoid usage of this singleton by using TitleValue
 199          * and the associated services when possible.
 200          *
 201          * @return TitleFormatter
 202          */
 203         private static function getTitleFormatter() {
 204                 // NOTE: we know that getMediaWikiTitleCodec() returns a MediaWikiTitleCodec,
 205                 //      which implements TitleFormatter.
 206                 return self::getMediaWikiTitleCodec();
 207         }
 208
 209         function __construct() {
 210         }
 211
 212         /**
 213          * Create a new Title from a prefixed DB key
 214          *
 215          * @param string $key The database key, which has underscores
 216          *      instead of spaces, possibly including namespace and
 217          *      interwiki prefixes
 218          * @return Title|null Title, or null on an error
 219          */
 220         public static function newFromDBkey( $key ) {
 221                 $t = new Title();
 222                 $t->mDbkeyform = $key;
 223
 224                 try {
 225                         $t->secureAndSplit();
 226                         return $t;
 227                 } catch ( MalformedTitleException $ex ) {
 228                         return null;
 229                 }
 230         }
 231
 232         /**
 233          * Create a new Title from a TitleValue
 234          *
 235          * @param TitleValue $titleValue Assumed to be safe.
 236          *
 237          * @return Title
 238          */
 239         public static function newFromTitleValue( TitleValue $titleValue ) {
 240                 return self::newFromLinkTarget( $titleValue );
 241         }
 242
 243         /**
 244          * Create a new Title from a LinkTarget
 245          *
 246          * @param LinkTarget $linkTarget Assumed to be safe.
 247          *
 248          * @return Title
 249          */
 250         public static function newFromLinkTarget( LinkTarget $linkTarget ) {
 251                 return self::makeTitle(
 252                         $linkTarget->getNamespace(),
 253                         $linkTarget->getText(),
 254                         $linkTarget->getFragment() );
 255         }
 256
 257         /**
 258          * Create a new Title from text, such as what one would find in a link. De-
 259          * codes any HTML entities in the text.
 260          *
 261          * @param string|int|null $text The link text; spaces, prefixes, and an
 262          *   initial ':' indicating the main namespace are accepted.
 263          * @param int $defaultNamespace The namespace to use if none is specified
 264          *   by a prefix.  If you want to force a specific namespace even if
 265          *   $text might begin with a namespace prefix, use makeTitle() or
 266          *   makeTitleSafe().
 267          * @throws InvalidArgumentException
 268          * @return Title|null Title or null on an error.
 269          */
 270         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 271                 if ( is_object( $text ) ) {
 272                         throw new InvalidArgumentException( '$text must be a string.' );
 273                 }
 274                 // DWIM: Integers can be passed in here when page titles are used as array keys.
 275                 if ( $text !== null && !is_string( $text ) && !is_int( $text ) ) {
 276                         wfDebugLog( 'T76305', wfGetAllCallers( 5 ) );
 277                         return null;
 278                 }
 279                 if ( $text === null ) {
 280                         return null;
 281                 }
 282
 283                 try {
 284                         return Title::newFromTextThrow( strval( $text ), $defaultNamespace );
 285                 } catch ( MalformedTitleException $ex ) {
 286                         return null;
 287                 }
 288         }
 289
 290         /**
 291          * Like Title::newFromText(), but throws MalformedTitleException when the title is invalid,
 292          * rather than returning null.
 293          *
 294          * The exception subclasses encode detailed information about why the title is invalid.
 295          *
 296          * @see Title::newFromText
 297          *
 298          * @since 1.25
 299          * @param string $text Title text to check
 300          * @param int $defaultNamespace
 301          * @throws MalformedTitleException If the title is invalid
 302          * @return Title
 303          */
 304         public static function newFromTextThrow( $text, $defaultNamespace = NS_MAIN ) {
 305                 if ( is_object( $text ) ) {
 306                         throw new MWException( '$text must be a string, given an object' );
 307                 }
 308
 309                 $titleCache = self::getTitleCache();
 310
 311                 // Wiki pages often contain multiple links to the same page.
 312                 // Title normalization and parsing can become expensive on pages with many
 313                 // links, so we can save a little time by caching them.
 314                 // In theory these are value objects and won't get changed...
 315                 if ( $defaultNamespace == NS_MAIN ) {
 316                         $t = $titleCache->get( $text );
 317                         if ( $t ) {
 318                                 return $t;
 319                         }
 320                 }
 321
 322                 // Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 323                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 324
 325                 $t = new Title();
 326                 $t->mDbkeyform = strtr( $filteredText, ' ', '_' );
 327                 $t->mDefaultNamespace = intval( $defaultNamespace );
 328
 329                 $t->secureAndSplit();
 330                 if ( $defaultNamespace == NS_MAIN ) {
 331                         $titleCache->set( $text, $t );
 332                 }
 333                 return $t;
 334         }
 335
 336         /**
 337          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 338          *
 339          * Example of wrong and broken code:
 340          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 341          *
 342          * Example of right code:
 343          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 344          *
 345          * Create a new Title from URL-encoded text. Ensures that
 346          * the given title's length does not exceed the maximum.
 347          *
 348          * @param string $url The title, as might be taken from a URL
 349          * @return Title|null The new object, or null on an error
 350          */
 351         public static function newFromURL( $url ) {
 352                 $t = new Title();
 353
 354                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 355                 # but some URLs used it as a space replacement and they still come
 356                 # from some external search tools.
 357                 if ( strpos( self::legalChars(), '+' ) === false ) {
 358                         $url = strtr( $url, '+', ' ' );
 359                 }
 360
 361                 $t->mDbkeyform = strtr( $url, ' ', '_' );
 362
 363                 try {
 364                         $t->secureAndSplit();
 365                         return $t;
 366                 } catch ( MalformedTitleException $ex ) {
 367                         return null;
 368                 }
 369         }
 370
 371         /**
 372          * @return HashBagOStuff
 373          */
 374         private static function getTitleCache() {
 375                 if ( self::$titleCache == null ) {
 376                         self::$titleCache = new HashBagOStuff( [ 'maxKeys' => self::CACHE_MAX ] );
 377                 }
 378                 return self::$titleCache;
 379         }
 380
 381         /**
 382          * Returns a list of fields that are to be selected for initializing Title
 383          * objects or LinkCache entries. Uses $wgContentHandlerUseDB to determine
 384          * whether to include page_content_model.
 385          *
 386          * @return array
 387          */
 388         protected static function getSelectFields() {
 389                 global $wgContentHandlerUseDB, $wgPageLanguageUseDB;
 390
 391                 $fields = [
 392                         'page_namespace', 'page_title', 'page_id',
 393                         'page_len', 'page_is_redirect', 'page_latest',
 394                 ];
 395
 396                 if ( $wgContentHandlerUseDB ) {
 397                         $fields[] = 'page_content_model';
 398                 }
 399
 400                 if ( $wgPageLanguageUseDB ) {
 401                         $fields[] = 'page_lang';
 402                 }
 403
 404                 return $fields;
 405         }
 406
 407         /**
 408          * Create a new Title from an article ID
 409          *
 410          * @param int $id The page_id corresponding to the Title to create
 411          * @param int $flags Use Title::GAID_FOR_UPDATE to use master
 412          * @return Title|null The new object, or null on an error
 413          */
 414         public static function newFromID( $id, $flags = 0 ) {
 415                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 416                 $row = $db->selectRow(
 417                         'page',
 418                         self::getSelectFields(),
 419                         [ 'page_id' => $id ],
 420                         __METHOD__
 421                 );
 422                 if ( $row !== false ) {
 423                         $title = Title::newFromRow( $row );
 424                 } else {
 425                         $title = null;
 426                 }
 427                 return $title;
 428         }
 429
 430         /**
 431          * Make an array of titles from an array of IDs
 432          *
 433          * @param int[] $ids Array of IDs
 434          * @return Title[] Array of Titles
 435          */
 436         public static function newFromIDs( $ids ) {
 437                 if ( !count( $ids ) ) {
 438                         return [];
 439                 }
 440                 $dbr = wfGetDB( DB_SLAVE );
 441
 442                 $res = $dbr->select(
 443                         'page',
 444                         self::getSelectFields(),
 445                         [ 'page_id' => $ids ],
 446                         __METHOD__
 447                 );
 448
 449                 $titles = [];
 450                 foreach ( $res as $row ) {
 451                         $titles[] = Title::newFromRow( $row );
 452                 }
 453                 return $titles;
 454         }
 455
 456         /**
 457          * Make a Title object from a DB row
 458          *
 459          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 460          * @return Title Corresponding Title
 461          */
 462         public static function newFromRow( $row ) {
 463                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 464                 $t->loadFromRow( $row );
 465                 return $t;
 466         }
 467
 468         /**
 469          * Load Title object fields from a DB row.
 470          * If false is given, the title will be treated as non-existing.
 471          *
 472          * @param stdClass|bool $row Database row
 473          */
 474         public function loadFromRow( $row ) {
 475                 if ( $row ) { // page found
 476                         if ( isset( $row->page_id ) ) {
 477                                 $this->mArticleID = (int)$row->page_id;
 478                         }
 479                         if ( isset( $row->page_len ) ) {
 480                                 $this->mLength = (int)$row->page_len;
 481                         }
 482                         if ( isset( $row->page_is_redirect ) ) {
 483                                 $this->mRedirect = (bool)$row->page_is_redirect;
 484                         }
 485                         if ( isset( $row->page_latest ) ) {
 486                                 $this->mLatestID = (int)$row->page_latest;
 487                         }
 488                         if ( isset( $row->page_content_model ) ) {
 489                                 $this->mContentModel = strval( $row->page_content_model );
 490                         } else {
 491                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 492                         }
 493                         if ( isset( $row->page_lang ) ) {
 494                                 $this->mDbPageLanguage = (string)$row->page_lang;
 495                         }
 496                         if ( isset( $row->page_restrictions ) ) {
 497                                 $this->mOldRestrictions = $row->page_restrictions;
 498                         }
 499                 } else { // page not found
 500                         $this->mArticleID = 0;
 501                         $this->mLength = 0;
 502                         $this->mRedirect = false;
 503                         $this->mLatestID = 0;
 504                         $this->mContentModel = false; # initialized lazily in getContentModel()
 505                 }
 506         }
 507
 508         /**
 509          * Create a new Title from a namespace index and a DB key.
 510          * It's assumed that $ns and $title are *valid*, for instance when
 511          * they came directly from the database or a special page name.
 512          * For convenience, spaces are converted to underscores so that
 513          * eg user_text fields can be used directly.
 514          *
 515          * @param int $ns The namespace of the article
 516          * @param string $title The unprefixed database key form
 517          * @param string $fragment The link fragment (after the "#")
 518          * @param string $interwiki The interwiki prefix
 519          * @return Title The new object
 520          */
 521         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 522                 $t = new Title();
 523                 $t->mInterwiki = $interwiki;
 524                 $t->mFragment = $fragment;
 525                 $t->mNamespace = $ns = intval( $ns );
 526                 $t->mDbkeyform = strtr( $title, ' ', '_' );
 527                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 528                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 529                 $t->mTextform = strtr( $title, '_', ' ' );
 530                 $t->mContentModel = false; # initialized lazily in getContentModel()
 531                 return $t;
 532         }
 533
 534         /**
 535          * Create a new Title from a namespace index and a DB key.
 536          * The parameters will be checked for validity, which is a bit slower
 537          * than makeTitle() but safer for user-provided data.
 538          *
 539          * @param int $ns The namespace of the article
 540          * @param string $title Database key form
 541          * @param string $fragment The link fragment (after the "#")
 542          * @param string $interwiki Interwiki prefix
 543          * @return Title|null The new object, or null on an error
 544          */
 545         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 546                 if ( !MWNamespace::exists( $ns ) ) {
 547                         return null;
 548                 }
 549
 550                 $t = new Title();
 551                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki, true );
 552
 553                 try {
 554                         $t->secureAndSplit();
 555                         return $t;
 556                 } catch ( MalformedTitleException $ex ) {
 557                         return null;
 558                 }
 559         }
 560
 561         /**
 562          * Create a new Title for the Main Page
 563          *
 564          * @return Title The new object
 565          */
 566         public static function newMainPage() {
 567                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 568                 // Don't give fatal errors if the message is broken
 569                 if ( !$title ) {
 570                         $title = Title::newFromText( 'Main Page' );
 571                 }
 572                 return $title;
 573         }
 574
 575         /**
 576          * Extract a redirect destination from a string and return the
 577          * Title, or null if the text doesn't contain a valid redirect
 578          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 579          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 580          *
 581          * @param string $text Text with possible redirect
 582          * @return Title
 583          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 584          */
 585         public static function newFromRedirectRecurse( $text ) {
 586                 ContentHandler::deprecated( __METHOD__, '1.21' );
 587
 588                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 589                 return $content->getUltimateRedirectTarget();
 590         }
 591
 592         /**
 593          * Get the prefixed DB key associated with an ID
 594          *
 595          * @param int $id The page_id of the article
 596          * @return Title|null An object representing the article, or null if no such article was found
 597          */
 598         public static function nameOf( $id ) {
 599                 $dbr = wfGetDB( DB_SLAVE );
 600
 601                 $s = $dbr->selectRow(
 602                         'page',
 603                         [ 'page_namespace', 'page_title' ],
 604                         [ 'page_id' => $id ],
 605                         __METHOD__
 606                 );
 607                 if ( $s === false ) {
 608                         return null;
 609                 }
 610
 611                 $n = self::makeName( $s->page_namespace, $s->page_title );
 612                 return $n;
 613         }
 614
 615         /**
 616          * Get a regex character class describing the legal characters in a link
 617          *
 618          * @return string The list of characters, not delimited
 619          */
 620         public static function legalChars() {
 621                 global $wgLegalTitleChars;
 622                 return $wgLegalTitleChars;
 623         }
 624
 625         /**
 626          * Returns a simple regex that will match on characters and sequences invalid in titles.
 627          * Note that this doesn't pick up many things that could be wrong with titles, but that
 628          * replacing this regex with something valid will make many titles valid.
 629          *
 630          * @deprecated since 1.25, use MediaWikiTitleCodec::getTitleInvalidRegex() instead
 631          *
 632          * @return string Regex string
 633          */
 634         static function getTitleInvalidRegex() {
 635                 wfDeprecated( __METHOD__, '1.25' );
 636                 return MediaWikiTitleCodec::getTitleInvalidRegex();
 637         }
 638
 639         /**
 640          * Utility method for converting a character sequence from bytes to Unicode.
 641          *
 642          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 643          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 644          *
 645          * @param string $byteClass
 646          * @return string
 647          */
 648         public static function convertByteClassToUnicodeClass( $byteClass ) {
 649                 $length = strlen( $byteClass );
 650                 // Input token queue
 651                 $x0 = $x1 = $x2 = '';
 652                 // Decoded queue
 653                 $d0 = $d1 = $d2 = '';
 654                 // Decoded integer codepoints
 655                 $ord0 = $ord1 = $ord2 = 0;
 656                 // Re-encoded queue
 657                 $r0 = $r1 = $r2 = '';
 658                 // Output
 659                 $out = '';
 660                 // Flags
 661                 $allowUnicode = false;
 662                 for ( $pos = 0; $pos < $length; $pos++ ) {
 663                         // Shift the queues down
 664                         $x2 = $x1;
 665                         $x1 = $x0;
 666                         $d2 = $d1;
 667                         $d1 = $d0;
 668                         $ord2 = $ord1;
 669                         $ord1 = $ord0;
 670                         $r2 = $r1;
 671                         $r1 = $r0;
 672                         // Load the current input token and decoded values
 673                         $inChar = $byteClass[$pos];
 674                         if ( $inChar == '\\' ) {
 675                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 676                                         $x0 = $inChar . $m[0];
 677                                         $d0 = chr( hexdec( $m[1] ) );
 678                                         $pos += strlen( $m[0] );
 679                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 680                                         $x0 = $inChar . $m[0];
 681                                         $d0 = chr( octdec( $m[0] ) );
 682                                         $pos += strlen( $m[0] );
 683                                 } elseif ( $pos + 1 >= $length ) {
 684                                         $x0 = $d0 = '\\';
 685                                 } else {
 686                                         $d0 = $byteClass[$pos + 1];
 687                                         $x0 = $inChar . $d0;
 688                                         $pos += 1;
 689                                 }
 690                         } else {
 691                                 $x0 = $d0 = $inChar;
 692                         }
 693                         $ord0 = ord( $d0 );
 694                         // Load the current re-encoded value
 695                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 696                                 $r0 = sprintf( '\x%02x', $ord0 );
 697                         } elseif ( $ord0 >= 0x80 ) {
 698                                 // Allow unicode if a single high-bit character appears
 699                                 $r0 = sprintf( '\x%02x', $ord0 );
 700                                 $allowUnicode = true;
 701                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 702                                 $r0 = '\\' . $d0;
 703                         } else {
 704                                 $r0 = $d0;
 705                         }
 706                         // Do the output
 707                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 708                                 // Range
 709                                 if ( $ord2 > $ord0 ) {
 710                                         // Empty range
 711                                 } elseif ( $ord0 >= 0x80 ) {
 712                                         // Unicode range
 713                                         $allowUnicode = true;
 714                                         if ( $ord2 < 0x80 ) {
 715                                                 // Keep the non-unicode section of the range
 716                                                 $out .= "$r2-\\x7F";
 717                                         }
 718                                 } else {
 719                                         // Normal range
 720                                         $out .= "$r2-$r0";
 721                                 }
 722                                 // Reset state to the initial value
 723                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 724                         } elseif ( $ord2 < 0x80 ) {
 725                                 // ASCII character
 726                                 $out .= $r2;
 727                         }
 728                 }
 729                 if ( $ord1 < 0x80 ) {
 730                         $out .= $r1;
 731                 }
 732                 if ( $ord0 < 0x80 ) {
 733                         $out .= $r0;
 734                 }
 735                 if ( $allowUnicode ) {
 736                         $out .= '\u0080-\uFFFF';
 737                 }
 738                 return $out;
 739         }
 740
 741         /**
 742          * Make a prefixed DB key from a DB key and a namespace index
 743          *
 744          * @param int $ns Numerical representation of the namespace
 745          * @param string $title The DB key form the title
 746          * @param string $fragment The link fragment (after the "#")
 747          * @param string $interwiki The interwiki prefix
 748          * @param bool $canonicalNamespace If true, use the canonical name for
 749          *   $ns instead of the localized version.
 750          * @return string The prefixed form of the title
 751          */
 752         public static function makeName( $ns, $title, $fragment = '', $interwiki = '',
 753                 $canonicalNamespace = false
 754         ) {
 755                 global $wgContLang;
 756
 757                 if ( $canonicalNamespace ) {
 758                         $namespace = MWNamespace::getCanonicalName( $ns );
 759                 } else {
 760                         $namespace = $wgContLang->getNsText( $ns );
 761                 }
 762                 $name = $namespace == '' ? $title : "$namespace:$title";
 763                 if ( strval( $interwiki ) != '' ) {
 764                         $name = "$interwiki:$name";
 765                 }
 766                 if ( strval( $fragment ) != '' ) {
 767                         $name .= '#' . $fragment;
 768                 }
 769                 return $name;
 770         }
 771
 772         /**
 773          * Escape a text fragment, say from a link, for a URL
 774          *
 775          * @param string $fragment Containing a URL or link fragment (after the "#")
 776          * @return string Escaped string
 777          */
 778         static function escapeFragmentForURL( $fragment ) {
 779                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 780                 # fragments appear not to work in IE (at least up to 7) or in at least
 781                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 782                 # to care if they aren't encoded.
 783                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 784         }
 785
 786         /**
 787          * Callback for usort() to do title sorts by (namespace, title)
 788          *
 789          * @param Title $a
 790          * @param Title $b
 791          *
 792          * @return int Result of string comparison, or namespace comparison
 793          */
 794         public static function compare( $a, $b ) {
 795                 if ( $a->getNamespace() == $b->getNamespace() ) {
 796                         return strcmp( $a->getText(), $b->getText() );
 797                 } else {
 798                         return $a->getNamespace() - $b->getNamespace();
 799                 }
 800         }
 801
 802         /**
 803          * Determine whether the object refers to a page within
 804          * this project (either this wiki or a wiki with a local
 805          * interwiki, see https://www.mediawiki.org/wiki/Manual:Interwiki_table#iw_local )
 806          *
 807          * @return bool True if this is an in-project interwiki link or a wikilink, false otherwise
 808          */
 809         public function isLocal() {
 810                 if ( $this->isExternal() ) {
 811                         $iw = Interwiki::fetch( $this->mInterwiki );
 812                         if ( $iw ) {
 813                                 return $iw->isLocal();
 814                         }
 815                 }
 816                 return true;
 817         }
 818
 819         /**
 820          * Is this Title interwiki?
 821          *
 822          * @return bool
 823          */
 824         public function isExternal() {
 825                 return $this->mInterwiki !== '';
 826         }
 827
 828         /**
 829          * Get the interwiki prefix
 830          *
 831          * Use Title::isExternal to check if a interwiki is set
 832          *
 833          * @return string Interwiki prefix
 834          */
 835         public function getInterwiki() {
 836                 return $this->mInterwiki;
 837         }
 838
 839         /**
 840          * Was this a local interwiki link?
 841          *
 842          * @return bool
 843          */
 844         public function wasLocalInterwiki() {
 845                 return $this->mLocalInterwiki;
 846         }
 847
 848         /**
 849          * Determine whether the object refers to a page within
 850          * this project and is transcludable.
 851          *
 852          * @return bool True if this is transcludable
 853          */
 854         public function isTrans() {
 855                 if ( !$this->isExternal() ) {
 856                         return false;
 857                 }
 858
 859                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 860         }
 861
 862         /**
 863          * Returns the DB name of the distant wiki which owns the object.
 864          *
 865          * @return string The DB name
 866          */
 867         public function getTransWikiID() {
 868                 if ( !$this->isExternal() ) {
 869                         return false;
 870                 }
 871
 872                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 873         }
 874
 875         /**
 876          * Get a TitleValue object representing this Title.
 877          *
 878          * @note Not all valid Titles have a corresponding valid TitleValue
 879          * (e.g. TitleValues cannot represent page-local links that have a
 880          * fragment but no title text).
 881          *
 882          * @return TitleValue|null
 883          */
 884         public function getTitleValue() {
 885                 if ( $this->mTitleValue === null ) {
 886                         try {
 887                                 $this->mTitleValue = new TitleValue(
 888                                         $this->getNamespace(),
 889                                         $this->getDBkey(),
 890                                         $this->getFragment() );
 891                         } catch ( InvalidArgumentException $ex ) {
 892                                 wfDebug( __METHOD__ . ': Can\'t create a TitleValue for [[' .
 893                                         $this->getPrefixedText() . ']]: ' . $ex->getMessage() . "\n" );
 894                         }
 895                 }
 896
 897                 return $this->mTitleValue;
 898         }
 899
 900         /**
 901          * Get the text form (spaces not underscores) of the main part
 902          *
 903          * @return string Main part of the title
 904          */
 905         public function getText() {
 906                 return $this->mTextform;
 907         }
 908
 909         /**
 910          * Get the URL-encoded form of the main part
 911          *
 912          * @return string Main part of the title, URL-encoded
 913          */
 914         public function getPartialURL() {
 915                 return $this->mUrlform;
 916         }
 917
 918         /**
 919          * Get the main part with underscores
 920          *
 921          * @return string Main part of the title, with underscores
 922          */
 923         public function getDBkey() {
 924                 return $this->mDbkeyform;
 925         }
 926
 927         /**
 928          * Get the DB key with the initial letter case as specified by the user
 929          *
 930          * @return string DB key
 931          */
 932         function getUserCaseDBKey() {
 933                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 934                         return $this->mUserCaseDBKey;
 935                 } else {
 936                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 937                         return $this->mDbkeyform;
 938                 }
 939         }
 940
 941         /**
 942          * Get the namespace index, i.e. one of the NS_xxxx constants.
 943          *
 944          * @return int Namespace index
 945          */
 946         public function getNamespace() {
 947                 return $this->mNamespace;
 948         }
 949
 950         /**
 951          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 952          *
 953          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
 954          * @return string Content model id
 955          */
 956         public function getContentModel( $flags = 0 ) {
 957                 if ( !$this->mContentModel && $this->getArticleID( $flags ) ) {
 958                         $linkCache = LinkCache::singleton();
 959                         $linkCache->addLinkObj( $this ); # in case we already had an article ID
 960                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 961                 }
 962
 963                 if ( !$this->mContentModel ) {
 964                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 965                 }
 966
 967                 return $this->mContentModel;
 968         }
 969
 970         /**
 971          * Convenience method for checking a title's content model name
 972          *
 973          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 974          * @return bool True if $this->getContentModel() == $id
 975          */
 976         public function hasContentModel( $id ) {
 977                 return $this->getContentModel() == $id;
 978         }
 979
 980         /**
 981          * Get the namespace text
 982          *
 983          * @return string Namespace text
 984          */
 985         public function getNsText() {
 986                 if ( $this->isExternal() ) {
 987                         // This probably shouldn't even happen,
 988                         // but for interwiki transclusion it sometimes does.
 989                         // Use the canonical namespaces if possible to try to
 990                         // resolve a foreign namespace.
 991                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 992                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 993                         }
 994                 }
 995
 996                 try {
 997                         $formatter = self::getTitleFormatter();
 998                         return $formatter->getNamespaceName( $this->mNamespace, $this->mDbkeyform );
 999                 } catch ( InvalidArgumentException $ex ) {
1000                         wfDebug( __METHOD__ . ': ' . $ex->getMessage() . "\n" );
1001                         return false;
1002                 }
1003         }
1004
1005         /**
1006          * Get the namespace text of the subject (rather than talk) page
1007          *
1008          * @return string Namespace text
1009          */
1010         public function getSubjectNsText() {
1011                 global $wgContLang;
1012                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
1013         }
1014
1015         /**
1016          * Get the namespace text of the talk page
1017          *
1018          * @return string Namespace text
1019          */
1020         public function getTalkNsText() {
1021                 global $wgContLang;
1022                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
1023         }
1024
1025         /**
1026          * Could this title have a corresponding talk page?
1027          *
1028          * @return bool
1029          */
1030         public function canTalk() {
1031                 return MWNamespace::canTalk( $this->mNamespace );
1032         }
1033
1034         /**
1035          * Is this in a namespace that allows actual pages?
1036          *
1037          * @return bool
1038          */
1039         public function canExist() {
1040                 return $this->mNamespace >= NS_MAIN;
1041         }
1042
1043         /**
1044          * Can this title be added to a user's watchlist?
1045          *
1046          * @return bool
1047          */
1048         public function isWatchable() {
1049                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
1050         }
1051
1052         /**
1053          * Returns true if this is a special page.
1054          *
1055          * @return bool
1056          */
1057         public function isSpecialPage() {
1058                 return $this->getNamespace() == NS_SPECIAL;
1059         }
1060
1061         /**
1062          * Returns true if this title resolves to the named special page
1063          *
1064          * @param string $name The special page name
1065          * @return bool
1066          */
1067         public function isSpecial( $name ) {
1068                 if ( $this->isSpecialPage() ) {
1069                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
1070                         if ( $name == $thisName ) {
1071                                 return true;
1072                         }
1073                 }
1074                 return false;
1075         }
1076
1077         /**
1078          * If the Title refers to a special page alias which is not the local default, resolve
1079          * the alias, and localise the name as necessary.  Otherwise, return $this
1080          *
1081          * @return Title
1082          */
1083         public function fixSpecialName() {
1084                 if ( $this->isSpecialPage() ) {
1085                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
1086                         if ( $canonicalName ) {
1087                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
1088                                 if ( $localName != $this->mDbkeyform ) {
1089                                         return Title::makeTitle( NS_SPECIAL, $localName );
1090                                 }
1091                         }
1092                 }
1093                 return $this;
1094         }
1095
1096         /**
1097          * Returns true if the title is inside the specified namespace.
1098          *
1099          * Please make use of this instead of comparing to getNamespace()
1100          * This function is much more resistant to changes we may make
1101          * to namespaces than code that makes direct comparisons.
1102          * @param int $ns The namespace
1103          * @return bool
1104          * @since 1.19
1105          */
1106         public function inNamespace( $ns ) {
1107                 return MWNamespace::equals( $this->getNamespace(), $ns );
1108         }
1109
1110         /**
1111          * Returns true if the title is inside one of the specified namespaces.
1112          *
1113          * @param int $namespaces,... The namespaces to check for
1114          * @return bool
1115          * @since 1.19
1116          */
1117         public function inNamespaces( /* ... */ ) {
1118                 $namespaces = func_get_args();
1119                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
1120                         $namespaces = $namespaces[0];
1121                 }
1122
1123                 foreach ( $namespaces as $ns ) {
1124                         if ( $this->inNamespace( $ns ) ) {
1125                                 return true;
1126                         }
1127                 }
1128
1129                 return false;
1130         }
1131
1132         /**
1133          * Returns true if the title has the same subject namespace as the
1134          * namespace specified.
1135          * For example this method will take NS_USER and return true if namespace
1136          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
1137          * as their subject namespace.
1138          *
1139          * This is MUCH simpler than individually testing for equivalence
1140          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
1141          * @since 1.19
1142          * @param int $ns
1143          * @return bool
1144          */
1145         public function hasSubjectNamespace( $ns ) {
1146                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
1147         }
1148
1149         /**
1150          * Is this Title in a namespace which contains content?
1151          * In other words, is this a content page, for the purposes of calculating
1152          * statistics, etc?
1153          *
1154          * @return bool
1155          */
1156         public function isContentPage() {
1157                 return MWNamespace::isContent( $this->getNamespace() );
1158         }
1159
1160         /**
1161          * Would anybody with sufficient privileges be able to move this page?
1162          * Some pages just aren't movable.
1163          *
1164          * @return bool
1165          */
1166         public function isMovable() {
1167                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1168                         // Interwiki title or immovable namespace. Hooks don't get to override here
1169                         return false;
1170                 }
1171
1172                 $result = true;
1173                 Hooks::run( 'TitleIsMovable', [ $this, &$result ] );
1174                 return $result;
1175         }
1176
1177         /**
1178          * Is this the mainpage?
1179          * @note Title::newFromText seems to be sufficiently optimized by the title
1180          * cache that we don't need to over-optimize by doing direct comparisons and
1181          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1182          * ends up reporting something differently than $title->isMainPage();
1183          *
1184          * @since 1.18
1185          * @return bool
1186          */
1187         public function isMainPage() {
1188                 return $this->equals( Title::newMainPage() );
1189         }
1190
1191         /**
1192          * Is this a subpage?
1193          *
1194          * @return bool
1195          */
1196         public function isSubpage() {
1197                 return MWNamespace::hasSubpages( $this->mNamespace )
1198                         ? strpos( $this->getText(), '/' ) !== false
1199                         : false;
1200         }
1201
1202         /**
1203          * Is this a conversion table for the LanguageConverter?
1204          *
1205          * @return bool
1206          */
1207         public function isConversionTable() {
1208                 // @todo ConversionTable should become a separate content model.
1209
1210                 return $this->getNamespace() == NS_MEDIAWIKI &&
1211                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1212         }
1213
1214         /**
1215          * Does that page contain wikitext, or it is JS, CSS or whatever?
1216          *
1217          * @return bool
1218          */
1219         public function isWikitextPage() {
1220                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1221         }
1222
1223         /**
1224          * Could this page contain custom CSS or JavaScript for the global UI.
1225          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1226          * or CONTENT_MODEL_JAVASCRIPT.
1227          *
1228          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage()
1229          * for that!
1230          *
1231          * Note that this method should not return true for pages that contain and
1232          * show "inactive" CSS or JS.
1233          *
1234          * @return bool
1235          * @todo FIXME: Rename to isSiteConfigPage() and remove deprecated hook
1236          */
1237         public function isCssOrJsPage() {
1238                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1239                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1240                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1241
1242                 # @note This hook is also called in ContentHandler::getDefaultModel.
1243                 #   It's called here again to make sure hook functions can force this
1244                 #   method to return true even outside the MediaWiki namespace.
1245
1246                 Hooks::run( 'TitleIsCssOrJsPage', [ $this, &$isCssOrJsPage ], '1.25' );
1247
1248                 return $isCssOrJsPage;
1249         }
1250
1251         /**
1252          * Is this a .css or .js subpage of a user page?
1253          * @return bool
1254          * @todo FIXME: Rename to isUserConfigPage()
1255          */
1256         public function isCssJsSubpage() {
1257                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1258                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1259                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1260         }
1261
1262         /**
1263          * Trim down a .css or .js subpage title to get the corresponding skin name
1264          *
1265          * @return string Containing skin name from .css or .js subpage title
1266          */
1267         public function getSkinFromCssJsSubpage() {
1268                 $subpage = explode( '/', $this->mTextform );
1269                 $subpage = $subpage[count( $subpage ) - 1];
1270                 $lastdot = strrpos( $subpage, '.' );
1271                 if ( $lastdot === false ) {
1272                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1273                 }
1274                 return substr( $subpage, 0, $lastdot );
1275         }
1276
1277         /**
1278          * Is this a .css subpage of a user page?
1279          *
1280          * @return bool
1281          */
1282         public function isCssSubpage() {
1283                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1284                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1285         }
1286
1287         /**
1288          * Is this a .js subpage of a user page?
1289          *
1290          * @return bool
1291          */
1292         public function isJsSubpage() {
1293                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1294                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1295         }
1296
1297         /**
1298          * Is this a talk page of some sort?
1299          *
1300          * @return bool
1301          */
1302         public function isTalkPage() {
1303                 return MWNamespace::isTalk( $this->getNamespace() );
1304         }
1305
1306         /**
1307          * Get a Title object associated with the talk page of this article
1308          *
1309          * @return Title The object for the talk page
1310          */
1311         public function getTalkPage() {
1312                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1313         }
1314
1315         /**
1316          * Get a title object associated with the subject page of this
1317          * talk page
1318          *
1319          * @return Title The object for the subject page
1320          */
1321         public function getSubjectPage() {
1322                 // Is this the same title?
1323                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1324                 if ( $this->getNamespace() == $subjectNS ) {
1325                         return $this;
1326                 }
1327                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1328         }
1329
1330         /**
1331          * Get the other title for this page, if this is a subject page
1332          * get the talk page, if it is a subject page get the talk page
1333          *
1334          * @since 1.25
1335          * @throws MWException
1336          * @return Title
1337          */
1338         public function getOtherPage() {
1339                 if ( $this->isSpecialPage() ) {
1340                         throw new MWException( 'Special pages cannot have other pages' );
1341                 }
1342                 if ( $this->isTalkPage() ) {
1343                         return $this->getSubjectPage();
1344                 } else {
1345                         return $this->getTalkPage();
1346                 }
1347         }
1348
1349         /**
1350          * Get the default namespace index, for when there is no namespace
1351          *
1352          * @return int Default namespace index
1353          */
1354         public function getDefaultNamespace() {
1355                 return $this->mDefaultNamespace;
1356         }
1357
1358         /**
1359          * Get the Title fragment (i.e.\ the bit after the #) in text form
1360          *
1361          * Use Title::hasFragment to check for a fragment
1362          *
1363          * @return string Title fragment
1364          */
1365         public function getFragment() {
1366                 return $this->mFragment;
1367         }
1368
1369         /**
1370          * Check if a Title fragment is set
1371          *
1372          * @return bool
1373          * @since 1.23
1374          */
1375         public function hasFragment() {
1376                 return $this->mFragment !== '';
1377         }
1378
1379         /**
1380          * Get the fragment in URL form, including the "#" character if there is one
1381          * @return string Fragment in URL form
1382          */
1383         public function getFragmentForURL() {
1384                 if ( !$this->hasFragment() ) {
1385                         return '';
1386                 } else {
1387                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1388                 }
1389         }
1390
1391         /**
1392          * Set the fragment for this title. Removes the first character from the
1393          * specified fragment before setting, so it assumes you're passing it with
1394          * an initial "#".
1395          *
1396          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1397          * Still in active use privately.
1398          *
1399          * @private
1400          * @param string $fragment Text
1401          */
1402         public function setFragment( $fragment ) {
1403                 $this->mFragment = strtr( substr( $fragment, 1 ), '_', ' ' );
1404         }
1405
1406         /**
1407          * Prefix some arbitrary text with the namespace or interwiki prefix
1408          * of this object
1409          *
1410          * @param string $name The text
1411          * @return string The prefixed text
1412          */
1413         private function prefix( $name ) {
1414                 $p = '';
1415                 if ( $this->isExternal() ) {
1416                         $p = $this->mInterwiki . ':';
1417                 }
1418
1419                 if ( 0 != $this->mNamespace ) {
1420                         $p .= $this->getNsText() . ':';
1421                 }
1422                 return $p . $name;
1423         }
1424
1425         /**
1426          * Get the prefixed database key form
1427          *
1428          * @return string The prefixed title, with underscores and
1429          *  any interwiki and namespace prefixes
1430          */
1431         public function getPrefixedDBkey() {
1432                 $s = $this->prefix( $this->mDbkeyform );
1433                 $s = strtr( $s, ' ', '_' );
1434                 return $s;
1435         }
1436
1437         /**
1438          * Get the prefixed title with spaces.
1439          * This is the form usually used for display
1440          *
1441          * @return string The prefixed title, with spaces
1442          */
1443         public function getPrefixedText() {
1444                 if ( $this->mPrefixedText === null ) {
1445                         $s = $this->prefix( $this->mTextform );
1446                         $s = strtr( $s, '_', ' ' );
1447                         $this->mPrefixedText = $s;
1448                 }
1449                 return $this->mPrefixedText;
1450         }
1451
1452         /**
1453          * Return a string representation of this title
1454          *
1455          * @return string Representation of this title
1456          */
1457         public function __toString() {
1458                 return $this->getPrefixedText();
1459         }
1460
1461         /**
1462          * Get the prefixed title with spaces, plus any fragment
1463          * (part beginning with '#')
1464          *
1465          * @return string The prefixed title, with spaces and the fragment, including '#'
1466          */
1467         public function getFullText() {
1468                 $text = $this->getPrefixedText();
1469                 if ( $this->hasFragment() ) {
1470                         $text .= '#' . $this->getFragment();
1471                 }
1472                 return $text;
1473         }
1474
1475         /**
1476          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1477          *
1478          * @par Example:
1479          * @code
1480          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1481          * # returns: 'Foo'
1482          * @endcode
1483          *
1484          * @return string Root name
1485          * @since 1.20
1486          */
1487         public function getRootText() {
1488                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1489                         return $this->getText();
1490                 }
1491
1492                 return strtok( $this->getText(), '/' );
1493         }
1494
1495         /**
1496          * Get the root page name title, i.e. the leftmost part before any slashes
1497          *
1498          * @par Example:
1499          * @code
1500          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1501          * # returns: Title{User:Foo}
1502          * @endcode
1503          *
1504          * @return Title Root title
1505          * @since 1.20
1506          */
1507         public function getRootTitle() {
1508                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1509         }
1510
1511         /**
1512          * Get the base page name without a namespace, i.e. the part before the subpage name
1513          *
1514          * @par Example:
1515          * @code
1516          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1517          * # returns: 'Foo/Bar'
1518          * @endcode
1519          *
1520          * @return string Base name
1521          */
1522         public function getBaseText() {
1523                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1524                         return $this->getText();
1525                 }
1526
1527                 $parts = explode( '/', $this->getText() );
1528                 # Don't discard the real title if there's no subpage involved
1529                 if ( count( $parts ) > 1 ) {
1530                         unset( $parts[count( $parts ) - 1] );
1531                 }
1532                 return implode( '/', $parts );
1533         }
1534
1535         /**
1536          * Get the base page name title, i.e. the part before the subpage name
1537          *
1538          * @par Example:
1539          * @code
1540          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1541          * # returns: Title{User:Foo/Bar}
1542          * @endcode
1543          *
1544          * @return Title Base title
1545          * @since 1.20
1546          */
1547         public function getBaseTitle() {
1548                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1549         }
1550
1551         /**
1552          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1553          *
1554          * @par Example:
1555          * @code
1556          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1557          * # returns: "Baz"
1558          * @endcode
1559          *
1560          * @return string Subpage name
1561          */
1562         public function getSubpageText() {
1563                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1564                         return $this->mTextform;
1565                 }
1566                 $parts = explode( '/', $this->mTextform );
1567                 return $parts[count( $parts ) - 1];
1568         }
1569
1570         /**
1571          * Get the title for a subpage of the current page
1572          *
1573          * @par Example:
1574          * @code
1575          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1576          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1577          * @endcode
1578          *
1579          * @param string $text The subpage name to add to the title
1580          * @return Title Subpage title
1581          * @since 1.20
1582          */
1583         public function getSubpage( $text ) {
1584                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1585         }
1586
1587         /**
1588          * Get a URL-encoded form of the subpage text
1589          *
1590          * @return string URL-encoded subpage name
1591          */
1592         public function getSubpageUrlForm() {
1593                 $text = $this->getSubpageText();
1594                 $text = wfUrlencode( strtr( $text, ' ', '_' ) );
1595                 return $text;
1596         }
1597
1598         /**
1599          * Get a URL-encoded title (not an actual URL) including interwiki
1600          *
1601          * @return string The URL-encoded form
1602          */
1603         public function getPrefixedURL() {
1604                 $s = $this->prefix( $this->mDbkeyform );
1605                 $s = wfUrlencode( strtr( $s, ' ', '_' ) );
1606                 return $s;
1607         }
1608
1609         /**
1610          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1611          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1612          * second argument named variant. This was deprecated in favor
1613          * of passing an array of option with a "variant" key
1614          * Once $query2 is removed for good, this helper can be dropped
1615          * and the wfArrayToCgi moved to getLocalURL();
1616          *
1617          * @since 1.19 (r105919)
1618          * @param array|string $query
1619          * @param bool $query2
1620          * @return string
1621          */
1622         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1623                 if ( $query2 !== false ) {
1624                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1625                                 "method called with a second parameter is deprecated. Add your " .
1626                                 "parameter to an array passed as the first parameter.", "1.19" );
1627                 }
1628                 if ( is_array( $query ) ) {
1629                         $query = wfArrayToCgi( $query );
1630                 }
1631                 if ( $query2 ) {
1632                         if ( is_string( $query2 ) ) {
1633                                 // $query2 is a string, we will consider this to be
1634                                 // a deprecated $variant argument and add it to the query
1635                                 $query2 = wfArrayToCgi( [ 'variant' => $query2 ] );
1636                         } else {
1637                                 $query2 = wfArrayToCgi( $query2 );
1638                         }
1639                         // If we have $query content add a & to it first
1640                         if ( $query ) {
1641                                 $query .= '&';
1642                         }
1643                         // Now append the queries together
1644                         $query .= $query2;
1645                 }
1646                 return $query;
1647         }
1648
1649         /**
1650          * Get a real URL referring to this title, with interwiki link and
1651          * fragment
1652          *
1653          * @see self::getLocalURL for the arguments.
1654          * @see wfExpandUrl
1655          * @param array|string $query
1656          * @param bool $query2
1657          * @param string $proto Protocol type to use in URL
1658          * @return string The URL
1659          */
1660         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1661                 $query = self::fixUrlQueryArgs( $query, $query2 );
1662
1663                 # Hand off all the decisions on urls to getLocalURL
1664                 $url = $this->getLocalURL( $query );
1665
1666                 # Expand the url to make it a full url. Note that getLocalURL has the
1667                 # potential to output full urls for a variety of reasons, so we use
1668                 # wfExpandUrl instead of simply prepending $wgServer
1669                 $url = wfExpandUrl( $url, $proto );
1670
1671                 # Finally, add the fragment.
1672                 $url .= $this->getFragmentForURL();
1673
1674                 Hooks::run( 'GetFullURL', [ &$this, &$url, $query ] );
1675                 return $url;
1676         }
1677
1678         /**
1679          * Get a URL with no fragment or server name (relative URL) from a Title object.
1680          * If this page is generated with action=render, however,
1681          * $wgServer is prepended to make an absolute URL.
1682          *
1683          * @see self::getFullURL to always get an absolute URL.
1684          * @see self::getLinkURL to always get a URL that's the simplest URL that will be
1685          *  valid to link, locally, to the current Title.
1686          * @see self::newFromText to produce a Title object.
1687          *
1688          * @param string|array $query An optional query string,
1689          *   not used for interwiki links. Can be specified as an associative array as well,
1690          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1691          *   Some query patterns will trigger various shorturl path replacements.
1692          * @param array $query2 An optional secondary query array. This one MUST
1693          *   be an array. If a string is passed it will be interpreted as a deprecated
1694          *   variant argument and urlencoded into a variant= argument.
1695          *   This second query argument will be added to the $query
1696          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1697          *   pair in the first parameter array instead.
1698          *
1699          * @return string String of the URL.
1700          */
1701         public function getLocalURL( $query = '', $query2 = false ) {
1702                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1703
1704                 $query = self::fixUrlQueryArgs( $query, $query2 );
1705
1706                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1707                 if ( $interwiki ) {
1708                         $namespace = $this->getNsText();
1709                         if ( $namespace != '' ) {
1710                                 # Can this actually happen? Interwikis shouldn't be parsed.
1711                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1712                                 $namespace .= ':';
1713                         }
1714                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1715                         $url = wfAppendQuery( $url, $query );
1716                 } else {
1717                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1718                         if ( $query == '' ) {
1719                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1720                                 Hooks::run( 'GetLocalURL::Article', [ &$this, &$url ] );
1721                         } else {
1722                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1723                                 $url = false;
1724                                 $matches = [];
1725
1726                                 if ( !empty( $wgActionPaths )
1727                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1728                                 ) {
1729                                         $action = urldecode( $matches[2] );
1730                                         if ( isset( $wgActionPaths[$action] ) ) {
1731                                                 $query = $matches[1];
1732                                                 if ( isset( $matches[4] ) ) {
1733                                                         $query .= $matches[4];
1734                                                 }
1735                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1736                                                 if ( $query != '' ) {
1737                                                         $url = wfAppendQuery( $url, $query );
1738                                                 }
1739                                         }
1740                                 }
1741
1742                                 if ( $url === false
1743                                         && $wgVariantArticlePath
1744                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1745                                         && $this->getPageLanguage()->hasVariants()
1746                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1747                                 ) {
1748                                         $variant = urldecode( $matches[1] );
1749                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1750                                                 // Only do the variant replacement if the given variant is a valid
1751                                                 // variant for the page's language.
1752                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1753                                                 $url = str_replace( '$1', $dbkey, $url );
1754                                         }
1755                                 }
1756
1757                                 if ( $url === false ) {
1758                                         if ( $query == '-' ) {
1759                                                 $query = '';
1760                                         }
1761                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1762                                 }
1763                         }
1764
1765                         Hooks::run( 'GetLocalURL::Internal', [ &$this, &$url, $query ] );
1766
1767                         // @todo FIXME: This causes breakage in various places when we
1768                         // actually expected a local URL and end up with dupe prefixes.
1769                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1770                                 $url = $wgServer . $url;
1771                         }
1772                 }
1773                 Hooks::run( 'GetLocalURL', [ &$this, &$url, $query ] );
1774                 return $url;
1775         }
1776
1777         /**
1778          * Get a URL that's the simplest URL that will be valid to link, locally,
1779          * to the current Title.  It includes the fragment, but does not include
1780          * the server unless action=render is used (or the link is external).  If
1781          * there's a fragment but the prefixed text is empty, we just return a link
1782          * to the fragment.
1783          *
1784          * The result obviously should not be URL-escaped, but does need to be
1785          * HTML-escaped if it's being output in HTML.
1786          *
1787          * @param array $query
1788          * @param bool $query2
1789          * @param string $proto Protocol to use; setting this will cause a full URL to be used
1790          * @see self::getLocalURL for the arguments.
1791          * @return string The URL
1792          */
1793         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1794                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1795                         $ret = $this->getFullURL( $query, $query2, $proto );
1796                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1797                         $ret = $this->getFragmentForURL();
1798                 } else {
1799                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1800                 }
1801                 return $ret;
1802         }
1803
1804         /**
1805          * Get the URL form for an internal link.
1806          * - Used in various CDN-related code, in case we have a different
1807          * internal hostname for the server from the exposed one.
1808          *
1809          * This uses $wgInternalServer to qualify the path, or $wgServer
1810          * if $wgInternalServer is not set. If the server variable used is
1811          * protocol-relative, the URL will be expanded to http://
1812          *
1813          * @see self::getLocalURL for the arguments.
1814          * @return string The URL
1815          */
1816         public function getInternalURL( $query = '', $query2 = false ) {
1817                 global $wgInternalServer, $wgServer;
1818                 $query = self::fixUrlQueryArgs( $query, $query2 );
1819                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1820                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1821                 Hooks::run( 'GetInternalURL', [ &$this, &$url, $query ] );
1822                 return $url;
1823         }
1824
1825         /**
1826          * Get the URL for a canonical link, for use in things like IRC and
1827          * e-mail notifications. Uses $wgCanonicalServer and the
1828          * GetCanonicalURL hook.
1829          *
1830          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1831          *
1832          * @see self::getLocalURL for the arguments.
1833          * @return string The URL
1834          * @since 1.18
1835          */
1836         public function getCanonicalURL( $query = '', $query2 = false ) {
1837                 $query = self::fixUrlQueryArgs( $query, $query2 );
1838                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1839                 Hooks::run( 'GetCanonicalURL', [ &$this, &$url, $query ] );
1840                 return $url;
1841         }
1842
1843         /**
1844          * Get the edit URL for this Title
1845          *
1846          * @return string The URL, or a null string if this is an interwiki link
1847          */
1848         public function getEditURL() {
1849                 if ( $this->isExternal() ) {
1850                         return '';
1851                 }
1852                 $s = $this->getLocalURL( 'action=edit' );
1853
1854                 return $s;
1855         }
1856
1857         /**
1858          * Can $user perform $action on this page?
1859          * This skips potentially expensive cascading permission checks
1860          * as well as avoids expensive error formatting
1861          *
1862          * Suitable for use for nonessential UI controls in common cases, but
1863          * _not_ for functional access control.
1864          *
1865          * May provide false positives, but should never provide a false negative.
1866          *
1867          * @param string $action Action that permission needs to be checked for
1868          * @param User $user User to check (since 1.19); $wgUser will be used if not provided.
1869          * @return bool
1870          */
1871         public function quickUserCan( $action, $user = null ) {
1872                 return $this->userCan( $action, $user, false );
1873         }
1874
1875         /**
1876          * Can $user perform $action on this page?
1877          *
1878          * @param string $action Action that permission needs to be checked for
1879          * @param User $user User to check (since 1.19); $wgUser will be used if not
1880          *   provided.
1881          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1882          * @return bool
1883          */
1884         public function userCan( $action, $user = null, $rigor = 'secure' ) {
1885                 if ( !$user instanceof User ) {
1886                         global $wgUser;
1887                         $user = $wgUser;
1888                 }
1889
1890                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $rigor, true ) );
1891         }
1892
1893         /**
1894          * Can $user perform $action on this page?
1895          *
1896          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1897          *
1898          * @param string $action Action that permission needs to be checked for
1899          * @param User $user User to check
1900          * @param string $rigor One of (quick,full,secure)
1901          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
1902          *   - full   : does cheap and expensive checks possibly from a slave
1903          *   - secure : does cheap and expensive checks, using the master as needed
1904          * @param array $ignoreErrors Array of Strings Set this to a list of message keys
1905          *   whose corresponding errors may be ignored.
1906          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
1907          */
1908         public function getUserPermissionsErrors(
1909                 $action, $user, $rigor = 'secure', $ignoreErrors = []
1910         ) {
1911                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $rigor );
1912
1913                 // Remove the errors being ignored.
1914                 foreach ( $errors as $index => $error ) {
1915                         $errKey = is_array( $error ) ? $error[0] : $error;
1916
1917                         if ( in_array( $errKey, $ignoreErrors ) ) {
1918                                 unset( $errors[$index] );
1919                         }
1920                         if ( $errKey instanceof MessageSpecifier && in_array( $errKey->getKey(), $ignoreErrors ) ) {
1921                                 unset( $errors[$index] );
1922                         }
1923                 }
1924
1925                 return $errors;
1926         }
1927
1928         /**
1929          * Permissions checks that fail most often, and which are easiest to test.
1930          *
1931          * @param string $action The action to check
1932          * @param User $user User to check
1933          * @param array $errors List of current errors
1934          * @param string $rigor Same format as Title::getUserPermissionsErrors()
1935          * @param bool $short Short circuit on first error
1936          *
1937          * @return array List of errors
1938          */
1939         private function checkQuickPermissions( $action, $user, $errors, $rigor, $short ) {
1940                 if ( !Hooks::run( 'TitleQuickPermissions',
1941                         [ $this, $user, $action, &$errors, ( $rigor !== 'quick' ), $short ] )
1942                 ) {
1943                         return $errors;
1944                 }
1945
1946                 if ( $action == 'create' ) {
1947                         if (
1948                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1949                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1950                         ) {
1951                                 $errors[] = $user->isAnon() ? [ 'nocreatetext' ] : [ 'nocreate-loggedin' ];
1952                         }
1953                 } elseif ( $action == 'move' ) {
1954                         if ( !$user->isAllowed( 'move-rootuserpages' )
1955                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1956                                 // Show user page-specific message only if the user can move other pages
1957                                 $errors[] = [ 'cant-move-user-page' ];
1958                         }
1959
1960                         // Check if user is allowed to move files if it's a file
1961                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1962                                 $errors[] = [ 'movenotallowedfile' ];
1963                         }
1964
1965                         // Check if user is allowed to move category pages if it's a category page
1966                         if ( $this->mNamespace == NS_CATEGORY && !$user->isAllowed( 'move-categorypages' ) ) {
1967                                 $errors[] = [ 'cant-move-category-page' ];
1968                         }
1969
1970                         if ( !$user->isAllowed( 'move' ) ) {
1971                                 // User can't move anything
1972                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1973                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1974                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1975                                         // custom message if logged-in users without any special rights can move
1976                                         $errors[] = [ 'movenologintext' ];
1977                                 } else {
1978                                         $errors[] = [ 'movenotallowed' ];
1979                                 }
1980                         }
1981                 } elseif ( $action == 'move-target' ) {
1982                         if ( !$user->isAllowed( 'move' ) ) {
1983                                 // User can't move anything
1984                                 $errors[] = [ 'movenotallowed' ];
1985                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1986                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1987                                 // Show user page-specific message only if the user can move other pages
1988                                 $errors[] = [ 'cant-move-to-user-page' ];
1989                         } elseif ( !$user->isAllowed( 'move-categorypages' )
1990                                         && $this->mNamespace == NS_CATEGORY ) {
1991                                 // Show category page-specific message only if the user can move other pages
1992                                 $errors[] = [ 'cant-move-to-category-page' ];
1993                         }
1994                 } elseif ( !$user->isAllowed( $action ) ) {
1995                         $errors[] = $this->missingPermissionError( $action, $short );
1996                 }
1997
1998                 return $errors;
1999         }
2000
2001         /**
2002          * Add the resulting error code to the errors array
2003          *
2004          * @param array $errors List of current errors
2005          * @param array $result Result of errors
2006          *
2007          * @return array List of errors
2008          */
2009         private function resultToError( $errors, $result ) {
2010                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
2011                         // A single array representing an error
2012                         $errors[] = $result;
2013                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
2014                         // A nested array representing multiple errors
2015                         $errors = array_merge( $errors, $result );
2016                 } elseif ( $result !== '' && is_string( $result ) ) {
2017                         // A string representing a message-id
2018                         $errors[] = [ $result ];
2019                 } elseif ( $result instanceof MessageSpecifier ) {
2020                         // A message specifier representing an error
2021                         $errors[] = [ $result ];
2022                 } elseif ( $result === false ) {
2023                         // a generic "We don't want them to do that"
2024                         $errors[] = [ 'badaccess-group0' ];
2025                 }
2026                 return $errors;
2027         }
2028
2029         /**
2030          * Check various permission hooks
2031          *
2032          * @param string $action The action to check
2033          * @param User $user User to check
2034          * @param array $errors List of current errors
2035          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2036          * @param bool $short Short circuit on first error
2037          *
2038          * @return array List of errors
2039          */
2040         private function checkPermissionHooks( $action, $user, $errors, $rigor, $short ) {
2041                 // Use getUserPermissionsErrors instead
2042                 $result = '';
2043                 if ( !Hooks::run( 'userCan', [ &$this, &$user, $action, &$result ] ) ) {
2044                         return $result ? [] : [ [ 'badaccess-group0' ] ];
2045                 }
2046                 // Check getUserPermissionsErrors hook
2047                 if ( !Hooks::run( 'getUserPermissionsErrors', [ &$this, &$user, $action, &$result ] ) ) {
2048                         $errors = $this->resultToError( $errors, $result );
2049                 }
2050                 // Check getUserPermissionsErrorsExpensive hook
2051                 if (
2052                         $rigor !== 'quick'
2053                         && !( $short && count( $errors ) > 0 )
2054                         && !Hooks::run( 'getUserPermissionsErrorsExpensive', [ &$this, &$user, $action, &$result ] )
2055                 ) {
2056                         $errors = $this->resultToError( $errors, $result );
2057                 }
2058
2059                 return $errors;
2060         }
2061
2062         /**
2063          * Check permissions on special pages & namespaces
2064          *
2065          * @param string $action The action to check
2066          * @param User $user User to check
2067          * @param array $errors List of current errors
2068          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2069          * @param bool $short Short circuit on first error
2070          *
2071          * @return array List of errors
2072          */
2073         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $rigor, $short ) {
2074                 # Only 'createaccount' can be performed on special pages,
2075                 # which don't actually exist in the DB.
2076                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
2077                         $errors[] = [ 'ns-specialprotected' ];
2078                 }
2079
2080                 # Check $wgNamespaceProtection for restricted namespaces
2081                 if ( $this->isNamespaceProtected( $user ) ) {
2082                         $ns = $this->mNamespace == NS_MAIN ?
2083                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
2084                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
2085                                 [ 'protectedinterface', $action ] : [ 'namespaceprotected', $ns, $action ];
2086                 }
2087
2088                 return $errors;
2089         }
2090
2091         /**
2092          * Check CSS/JS sub-page permissions
2093          *
2094          * @param string $action The action to check
2095          * @param User $user User to check
2096          * @param array $errors List of current errors
2097          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2098          * @param bool $short Short circuit on first error
2099          *
2100          * @return array List of errors
2101          */
2102         private function checkCSSandJSPermissions( $action, $user, $errors, $rigor, $short ) {
2103                 # Protect css/js subpages of user pages
2104                 # XXX: this might be better using restrictions
2105                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2106                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2107                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2108                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2109                                         $errors[] = [ 'mycustomcssprotected', $action ];
2110                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2111                                         $errors[] = [ 'mycustomjsprotected', $action ];
2112                                 }
2113                         } else {
2114                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2115                                         $errors[] = [ 'customcssprotected', $action ];
2116                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2117                                         $errors[] = [ 'customjsprotected', $action ];
2118                                 }
2119                         }
2120                 }
2121
2122                 return $errors;
2123         }
2124
2125         /**
2126          * Check against page_restrictions table requirements on this
2127          * page. The user must possess all required rights for this
2128          * action.
2129          *
2130          * @param string $action The action to check
2131          * @param User $user User to check
2132          * @param array $errors List of current errors
2133          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2134          * @param bool $short Short circuit on first error
2135          *
2136          * @return array List of errors
2137          */
2138         private function checkPageRestrictions( $action, $user, $errors, $rigor, $short ) {
2139                 foreach ( $this->getRestrictions( $action ) as $right ) {
2140                         // Backwards compatibility, rewrite sysop -> editprotected
2141                         if ( $right == 'sysop' ) {
2142                                 $right = 'editprotected';
2143                         }
2144                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2145                         if ( $right == 'autoconfirmed' ) {
2146                                 $right = 'editsemiprotected';
2147                         }
2148                         if ( $right == '' ) {
2149                                 continue;
2150                         }
2151                         if ( !$user->isAllowed( $right ) ) {
2152                                 $errors[] = [ 'protectedpagetext', $right, $action ];
2153                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2154                                 $errors[] = [ 'protectedpagetext', 'protect', $action ];
2155                         }
2156                 }
2157
2158                 return $errors;
2159         }
2160
2161         /**
2162          * Check restrictions on cascading pages.
2163          *
2164          * @param string $action The action to check
2165          * @param User $user User to check
2166          * @param array $errors List of current errors
2167          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2168          * @param bool $short Short circuit on first error
2169          *
2170          * @return array List of errors
2171          */
2172         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $rigor, $short ) {
2173                 if ( $rigor !== 'quick' && !$this->isCssJsSubpage() ) {
2174                         # We /could/ use the protection level on the source page, but it's
2175                         # fairly ugly as we have to establish a precedence hierarchy for pages
2176                         # included by multiple cascade-protected pages. So just restrict
2177                         # it to people with 'protect' permission, as they could remove the
2178                         # protection anyway.
2179                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2180                         # Cascading protection depends on more than this page...
2181                         # Several cascading protected pages may include this page...
2182                         # Check each cascading level
2183                         # This is only for protection restrictions, not for all actions
2184                         if ( isset( $restrictions[$action] ) ) {
2185                                 foreach ( $restrictions[$action] as $right ) {
2186                                         // Backwards compatibility, rewrite sysop -> editprotected
2187                                         if ( $right == 'sysop' ) {
2188                                                 $right = 'editprotected';
2189                                         }
2190                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2191                                         if ( $right == 'autoconfirmed' ) {
2192                                                 $right = 'editsemiprotected';
2193                                         }
2194                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2195                                                 $pages = '';
2196                                                 foreach ( $cascadingSources as $page ) {
2197                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2198                                                 }
2199                                                 $errors[] = [ 'cascadeprotected', count( $cascadingSources ), $pages, $action ];
2200                                         }
2201                                 }
2202                         }
2203                 }
2204
2205                 return $errors;
2206         }
2207
2208         /**
2209          * Check action permissions not already checked in checkQuickPermissions
2210          *
2211          * @param string $action The action to check
2212          * @param User $user User to check
2213          * @param array $errors List of current errors
2214          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2215          * @param bool $short Short circuit on first error
2216          *
2217          * @return array List of errors
2218          */
2219         private function checkActionPermissions( $action, $user, $errors, $rigor, $short ) {
2220                 global $wgDeleteRevisionsLimit, $wgLang;
2221
2222                 if ( $action == 'protect' ) {
2223                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $rigor, true ) ) ) {
2224                                 // If they can't edit, they shouldn't protect.
2225                                 $errors[] = [ 'protect-cantedit' ];
2226                         }
2227                 } elseif ( $action == 'create' ) {
2228                         $title_protection = $this->getTitleProtection();
2229                         if ( $title_protection ) {
2230                                 if ( $title_protection['permission'] == ''
2231                                         || !$user->isAllowed( $title_protection['permission'] )
2232                                 ) {
2233                                         $errors[] = [
2234                                                 'titleprotected',
2235                                                 User::whoIs( $title_protection['user'] ),
2236                                                 $title_protection['reason']
2237                                         ];
2238                                 }
2239                         }
2240                 } elseif ( $action == 'move' ) {
2241                         // Check for immobile pages
2242                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2243                                 // Specific message for this case
2244                                 $errors[] = [ 'immobile-source-namespace', $this->getNsText() ];
2245                         } elseif ( !$this->isMovable() ) {
2246                                 // Less specific message for rarer cases
2247                                 $errors[] = [ 'immobile-source-page' ];
2248                         }
2249                 } elseif ( $action == 'move-target' ) {
2250                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2251                                 $errors[] = [ 'immobile-target-namespace', $this->getNsText() ];
2252                         } elseif ( !$this->isMovable() ) {
2253                                 $errors[] = [ 'immobile-target-page' ];
2254                         }
2255                 } elseif ( $action == 'delete' ) {
2256                         $tempErrors = $this->checkPageRestrictions( 'edit', $user, [], $rigor, true );
2257                         if ( !$tempErrors ) {
2258                                 $tempErrors = $this->checkCascadingSourcesRestrictions( 'edit',
2259                                         $user, $tempErrors, $rigor, true );
2260                         }
2261                         if ( $tempErrors ) {
2262                                 // If protection keeps them from editing, they shouldn't be able to delete.
2263                                 $errors[] = [ 'deleteprotected' ];
2264                         }
2265                         if ( $rigor !== 'quick' && $wgDeleteRevisionsLimit
2266                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2267                         ) {
2268                                 $errors[] = [ 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) ];
2269                         }
2270                 }
2271                 return $errors;
2272         }
2273
2274         /**
2275          * Check that the user isn't blocked from editing.
2276          *
2277          * @param string $action The action to check
2278          * @param User $user User to check
2279          * @param array $errors List of current errors
2280          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2281          * @param bool $short Short circuit on first error
2282          *
2283          * @return array List of errors
2284          */
2285         private function checkUserBlock( $action, $user, $errors, $rigor, $short ) {
2286                 // Account creation blocks handled at userlogin.
2287                 // Unblocking handled in SpecialUnblock
2288                 if ( $rigor === 'quick' || in_array( $action, [ 'createaccount', 'unblock' ] ) ) {
2289                         return $errors;
2290                 }
2291
2292                 global $wgEmailConfirmToEdit;
2293
2294                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2295                         $errors[] = [ 'confirmedittext' ];
2296                 }
2297
2298                 $useSlave = ( $rigor !== 'secure' );
2299                 if ( ( $action == 'edit' || $action == 'create' )
2300                         && !$user->isBlockedFrom( $this, $useSlave )
2301                 ) {
2302                         // Don't block the user from editing their own talk page unless they've been
2303                         // explicitly blocked from that too.
2304                 } elseif ( $user->isBlocked() && $user->getBlock()->prevents( $action ) !== false ) {
2305                         // @todo FIXME: Pass the relevant context into this function.
2306                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2307                 }
2308
2309                 return $errors;
2310         }
2311
2312         /**
2313          * Check that the user is allowed to read this page.
2314          *
2315          * @param string $action The action to check
2316          * @param User $user User to check
2317          * @param array $errors List of current errors
2318          * @param string $rigor Same format as Title::getUserPermissionsErrors()
2319          * @param bool $short Short circuit on first error
2320          *
2321          * @return array List of errors
2322          */
2323         private function checkReadPermissions( $action, $user, $errors, $rigor, $short ) {
2324                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2325
2326                 $whitelisted = false;
2327                 if ( User::isEveryoneAllowed( 'read' ) ) {
2328                         # Shortcut for public wikis, allows skipping quite a bit of code
2329                         $whitelisted = true;
2330                 } elseif ( $user->isAllowed( 'read' ) ) {
2331                         # If the user is allowed to read pages, he is allowed to read all pages
2332                         $whitelisted = true;
2333                 } elseif ( $this->isSpecial( 'Userlogin' )
2334                         || $this->isSpecial( 'ChangePassword' )
2335                         || $this->isSpecial( 'PasswordReset' )
2336                 ) {
2337                         # Always grant access to the login page.
2338                         # Even anons need to be able to log in.
2339                         $whitelisted = true;
2340                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2341                         # Time to check the whitelist
2342                         # Only do these checks is there's something to check against
2343                         $name = $this->getPrefixedText();
2344                         $dbName = $this->getPrefixedDBkey();
2345
2346                         // Check for explicit whitelisting with and without underscores
2347                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2348                                 $whitelisted = true;
2349                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2350                                 # Old settings might have the title prefixed with
2351                                 # a colon for main-namespace pages
2352                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2353                                         $whitelisted = true;
2354                                 }
2355                         } elseif ( $this->isSpecialPage() ) {
2356                                 # If it's a special page, ditch the subpage bit and check again
2357                                 $name = $this->getDBkey();
2358                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2359                                 if ( $name ) {
2360                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2361                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2362                                                 $whitelisted = true;
2363                                         }
2364                                 }
2365                         }
2366                 }
2367
2368                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2369                         $name = $this->getPrefixedText();
2370                         // Check for regex whitelisting
2371                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2372                                 if ( preg_match( $listItem, $name ) ) {
2373                                         $whitelisted = true;
2374                                         break;
2375                                 }
2376                         }
2377                 }
2378
2379                 if ( !$whitelisted ) {
2380                         # If the title is not whitelisted, give extensions a chance to do so...
2381                         Hooks::run( 'TitleReadWhitelist', [ $this, $user, &$whitelisted ] );
2382                         if ( !$whitelisted ) {
2383                                 $errors[] = $this->missingPermissionError( $action, $short );
2384                         }
2385                 }
2386
2387                 return $errors;
2388         }
2389
2390         /**
2391          * Get a description array when the user doesn't have the right to perform
2392          * $action (i.e. when User::isAllowed() returns false)
2393          *
2394          * @param string $action The action to check
2395          * @param bool $short Short circuit on first error
2396          * @return array List of errors
2397          */
2398         private function missingPermissionError( $action, $short ) {
2399                 // We avoid expensive display logic for quickUserCan's and such
2400                 if ( $short ) {
2401                         return [ 'badaccess-group0' ];
2402                 }
2403
2404                 $groups = array_map( [ 'User', 'makeGroupLinkWiki' ],
2405                         User::getGroupsWithPermission( $action ) );
2406
2407                 if ( count( $groups ) ) {
2408                         global $wgLang;
2409                         return [
2410                                 'badaccess-groups',
2411                                 $wgLang->commaList( $groups ),
2412                                 count( $groups )
2413                         ];
2414                 } else {
2415                         return [ 'badaccess-group0' ];
2416                 }
2417         }
2418
2419         /**
2420          * Can $user perform $action on this page? This is an internal function,
2421          * with multiple levels of checks depending on performance needs; see $rigor below.
2422          * It does not check wfReadOnly().
2423          *
2424          * @param string $action Action that permission needs to be checked for
2425          * @param User $user User to check
2426          * @param string $rigor One of (quick,full,secure)
2427          *   - quick  : does cheap permission checks from slaves (usable for GUI creation)
2428          *   - full   : does cheap and expensive checks possibly from a slave
2429          *   - secure : does cheap and expensive checks, using the master as needed
2430          * @param bool $short Set this to true to stop after the first permission error.
2431          * @return array Array of arrays of the arguments to wfMessage to explain permissions problems.
2432          */
2433         protected function getUserPermissionsErrorsInternal(
2434                 $action, $user, $rigor = 'secure', $short = false
2435         ) {
2436                 if ( $rigor === true ) {
2437                         $rigor = 'secure'; // b/c
2438                 } elseif ( $rigor === false ) {
2439                         $rigor = 'quick'; // b/c
2440                 } elseif ( !in_array( $rigor, [ 'quick', 'full', 'secure' ] ) ) {
2441                         throw new Exception( "Invalid rigor parameter '$rigor'." );
2442                 }
2443
2444                 # Read has special handling
2445                 if ( $action == 'read' ) {
2446                         $checks = [
2447                                 'checkPermissionHooks',
2448                                 'checkReadPermissions',
2449                         ];
2450                 # Don't call checkSpecialsAndNSPermissions or checkCSSandJSPermissions
2451                 # here as it will lead to duplicate error messages. This is okay to do
2452                 # since anywhere that checks for create will also check for edit, and
2453                 # those checks are called for edit.
2454                 } elseif ( $action == 'create' ) {
2455                         $checks = [
2456                                 'checkQuickPermissions',
2457                                 'checkPermissionHooks',
2458                                 'checkPageRestrictions',
2459                                 'checkCascadingSourcesRestrictions',
2460                                 'checkActionPermissions',
2461                                 'checkUserBlock'
2462                         ];
2463                 } else {
2464                         $checks = [
2465                                 'checkQuickPermissions',
2466                                 'checkPermissionHooks',
2467                                 'checkSpecialsAndNSPermissions',
2468                                 'checkCSSandJSPermissions',
2469                                 'checkPageRestrictions',
2470                                 'checkCascadingSourcesRestrictions',
2471                                 'checkActionPermissions',
2472                                 'checkUserBlock'
2473                         ];
2474                 }
2475
2476                 $errors = [];
2477                 while ( count( $checks ) > 0 &&
2478                                 !( $short && count( $errors ) > 0 ) ) {
2479                         $method = array_shift( $checks );
2480                         $errors = $this->$method( $action, $user, $errors, $rigor, $short );
2481                 }
2482
2483                 return $errors;
2484         }
2485
2486         /**
2487          * Get a filtered list of all restriction types supported by this wiki.
2488          * @param bool $exists True to get all restriction types that apply to
2489          * titles that do exist, False for all restriction types that apply to
2490          * titles that do not exist
2491          * @return array
2492          */
2493         public static function getFilteredRestrictionTypes( $exists = true ) {
2494                 global $wgRestrictionTypes;
2495                 $types = $wgRestrictionTypes;
2496                 if ( $exists ) {
2497                         # Remove the create restriction for existing titles
2498                         $types = array_diff( $types, [ 'create' ] );
2499                 } else {
2500                         # Only the create and upload restrictions apply to non-existing titles
2501                         $types = array_intersect( $types, [ 'create', 'upload' ] );
2502                 }
2503                 return $types;
2504         }
2505
2506         /**
2507          * Returns restriction types for the current Title
2508          *
2509          * @return array Applicable restriction types
2510          */
2511         public function getRestrictionTypes() {
2512                 if ( $this->isSpecialPage() ) {
2513                         return [];
2514                 }
2515
2516                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2517
2518                 if ( $this->getNamespace() != NS_FILE ) {
2519                         # Remove the upload restriction for non-file titles
2520                         $types = array_diff( $types, [ 'upload' ] );
2521                 }
2522
2523                 Hooks::run( 'TitleGetRestrictionTypes', [ $this, &$types ] );
2524
2525                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2526                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2527
2528                 return $types;
2529         }
2530
2531         /**
2532          * Is this title subject to title protection?
2533          * Title protection is the one applied against creation of such title.
2534          *
2535          * @return array|bool An associative array representing any existent title
2536          *   protection, or false if there's none.
2537          */
2538         public function getTitleProtection() {
2539                 // Can't protect pages in special namespaces
2540                 if ( $this->getNamespace() < 0 ) {
2541                         return false;
2542                 }
2543
2544                 // Can't protect pages that exist.
2545                 if ( $this->exists() ) {
2546                         return false;
2547                 }
2548
2549                 if ( $this->mTitleProtection === null ) {
2550                         $dbr = wfGetDB( DB_SLAVE );
2551                         $res = $dbr->select(
2552                                 'protected_titles',
2553                                 [
2554                                         'user' => 'pt_user',
2555                                         'reason' => 'pt_reason',
2556                                         'expiry' => 'pt_expiry',
2557                                         'permission' => 'pt_create_perm'
2558                                 ],
2559                                 [ 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ],
2560                                 __METHOD__
2561                         );
2562
2563                         // fetchRow returns false if there are no rows.
2564                         $row = $dbr->fetchRow( $res );
2565                         if ( $row ) {
2566                                 if ( $row['permission'] == 'sysop' ) {
2567                                         $row['permission'] = 'editprotected'; // B/C
2568                                 }
2569                                 if ( $row['permission'] == 'autoconfirmed' ) {
2570                                         $row['permission'] = 'editsemiprotected'; // B/C
2571                                 }
2572                                 $row['expiry'] = $dbr->decodeExpiry( $row['expiry'] );
2573                         }
2574                         $this->mTitleProtection = $row;
2575                 }
2576                 return $this->mTitleProtection;
2577         }
2578
2579         /**
2580          * Remove any title protection due to page existing
2581          */
2582         public function deleteTitleProtection() {
2583                 $dbw = wfGetDB( DB_MASTER );
2584
2585                 $dbw->delete(
2586                         'protected_titles',
2587                         [ 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ],
2588                         __METHOD__
2589                 );
2590                 $this->mTitleProtection = false;
2591         }
2592
2593         /**
2594          * Is this page "semi-protected" - the *only* protection levels are listed
2595          * in $wgSemiprotectedRestrictionLevels?
2596          *
2597          * @param string $action Action to check (default: edit)
2598          * @return bool
2599          */
2600         public function isSemiProtected( $action = 'edit' ) {
2601                 global $wgSemiprotectedRestrictionLevels;
2602
2603                 $restrictions = $this->getRestrictions( $action );
2604                 $semi = $wgSemiprotectedRestrictionLevels;
2605                 if ( !$restrictions || !$semi ) {
2606                         // Not protected, or all protection is full protection
2607                         return false;
2608                 }
2609
2610                 // Remap autoconfirmed to editsemiprotected for BC
2611                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2612                         $semi[$key] = 'editsemiprotected';
2613                 }
2614                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2615                         $restrictions[$key] = 'editsemiprotected';
2616                 }
2617
2618                 return !array_diff( $restrictions, $semi );
2619         }
2620
2621         /**
2622          * Does the title correspond to a protected article?
2623          *
2624          * @param string $action The action the page is protected from,
2625          * by default checks all actions.
2626          * @return bool
2627          */
2628         public function isProtected( $action = '' ) {
2629                 global $wgRestrictionLevels;
2630
2631                 $restrictionTypes = $this->getRestrictionTypes();
2632
2633                 # Special pages have inherent protection
2634                 if ( $this->isSpecialPage() ) {
2635                         return true;
2636                 }
2637
2638                 # Check regular protection levels
2639                 foreach ( $restrictionTypes as $type ) {
2640                         if ( $action == $type || $action == '' ) {
2641                                 $r = $this->getRestrictions( $type );
2642                                 foreach ( $wgRestrictionLevels as $level ) {
2643                                         if ( in_array( $level, $r ) && $level != '' ) {
2644                                                 return true;
2645                                         }
2646                                 }
2647                         }
2648                 }
2649
2650                 return false;
2651         }
2652
2653         /**
2654          * Determines if $user is unable to edit this page because it has been protected
2655          * by $wgNamespaceProtection.
2656          *
2657          * @param User $user User object to check permissions
2658          * @return bool
2659          */
2660         public function isNamespaceProtected( User $user ) {
2661                 global $wgNamespaceProtection;
2662
2663                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2664                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2665                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2666                                         return true;
2667                                 }
2668                         }
2669                 }
2670                 return false;
2671         }
2672
2673         /**
2674          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2675          *
2676          * @return bool If the page is subject to cascading restrictions.
2677          */
2678         public function isCascadeProtected() {
2679                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2680                 return ( $sources > 0 );
2681         }
2682
2683         /**
2684          * Determines whether cascading protection sources have already been loaded from
2685          * the database.
2686          *
2687          * @param bool $getPages True to check if the pages are loaded, or false to check
2688          * if the status is loaded.
2689          * @return bool Whether or not the specified information has been loaded
2690          * @since 1.23
2691          */
2692         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2693                 return $getPages ? $this->mCascadeSources !== null : $this->mHasCascadingRestrictions !== null;
2694         }
2695
2696         /**
2697          * Cascading protection: Get the source of any cascading restrictions on this page.
2698          *
2699          * @param bool $getPages Whether or not to retrieve the actual pages
2700          *        that the restrictions have come from and the actual restrictions
2701          *        themselves.
2702          * @return array Two elements: First is an array of Title objects of the
2703          *        pages from which cascading restrictions have come, false for
2704          *        none, or true if such restrictions exist but $getPages was not
2705          *        set. Second is an array like that returned by
2706          *        Title::getAllRestrictions(), or an empty array if $getPages is
2707          *        false.
2708          */
2709         public function getCascadeProtectionSources( $getPages = true ) {
2710                 $pagerestrictions = [];
2711
2712                 if ( $this->mCascadeSources !== null && $getPages ) {
2713                         return [ $this->mCascadeSources, $this->mCascadingRestrictions ];
2714                 } elseif ( $this->mHasCascadingRestrictions !== null && !$getPages ) {
2715                         return [ $this->mHasCascadingRestrictions, $pagerestrictions ];
2716                 }
2717
2718                 $dbr = wfGetDB( DB_SLAVE );
2719
2720                 if ( $this->getNamespace() == NS_FILE ) {
2721                         $tables = [ 'imagelinks', 'page_restrictions' ];
2722                         $where_clauses = [
2723                                 'il_to' => $this->getDBkey(),
2724                                 'il_from=pr_page',
2725                                 'pr_cascade' => 1
2726                         ];
2727                 } else {
2728                         $tables = [ 'templatelinks', 'page_restrictions' ];
2729                         $where_clauses = [
2730                                 'tl_namespace' => $this->getNamespace(),
2731                                 'tl_title' => $this->getDBkey(),
2732                                 'tl_from=pr_page',
2733                                 'pr_cascade' => 1
2734                         ];
2735                 }
2736
2737                 if ( $getPages ) {
2738                         $cols = [ 'pr_page', 'page_namespace', 'page_title',
2739                                 'pr_expiry', 'pr_type', 'pr_level' ];
2740                         $where_clauses[] = 'page_id=pr_page';
2741                         $tables[] = 'page';
2742                 } else {
2743                         $cols = [ 'pr_expiry' ];
2744                 }
2745
2746                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2747
2748                 $sources = $getPages ? [] : false;
2749                 $now = wfTimestampNow();
2750
2751                 foreach ( $res as $row ) {
2752                         $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2753                         if ( $expiry > $now ) {
2754                                 if ( $getPages ) {
2755                                         $page_id = $row->pr_page;
2756                                         $page_ns = $row->page_namespace;
2757                                         $page_title = $row->page_title;
2758                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2759                                         # Add groups needed for each restriction type if its not already there
2760                                         # Make sure this restriction type still exists
2761
2762                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2763                                                 $pagerestrictions[$row->pr_type] = [];
2764                                         }
2765
2766                                         if (
2767                                                 isset( $pagerestrictions[$row->pr_type] )
2768                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2769                                         ) {
2770                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2771                                         }
2772                                 } else {
2773                                         $sources = true;
2774                                 }
2775                         }
2776                 }
2777
2778                 if ( $getPages ) {
2779                         $this->mCascadeSources = $sources;
2780                         $this->mCascadingRestrictions = $pagerestrictions;
2781                 } else {
2782                         $this->mHasCascadingRestrictions = $sources;
2783                 }
2784
2785                 return [ $sources, $pagerestrictions ];
2786         }
2787
2788         /**
2789          * Accessor for mRestrictionsLoaded
2790          *
2791          * @return bool Whether or not the page's restrictions have already been
2792          * loaded from the database
2793          * @since 1.23
2794          */
2795         public function areRestrictionsLoaded() {
2796                 return $this->mRestrictionsLoaded;
2797         }
2798
2799         /**
2800          * Accessor/initialisation for mRestrictions
2801          *
2802          * @param string $action Action that permission needs to be checked for
2803          * @return array Restriction levels needed to take the action. All levels are
2804          *     required. Note that restriction levels are normally user rights, but 'sysop'
2805          *     and 'autoconfirmed' are also allowed for backwards compatibility. These should
2806          *     be mapped to 'editprotected' and 'editsemiprotected' respectively.
2807          */
2808         public function getRestrictions( $action ) {
2809                 if ( !$this->mRestrictionsLoaded ) {
2810                         $this->loadRestrictions();
2811                 }
2812                 return isset( $this->mRestrictions[$action] )
2813                                 ? $this->mRestrictions[$action]
2814                                 : [];
2815         }
2816
2817         /**
2818          * Accessor/initialisation for mRestrictions
2819          *
2820          * @return array Keys are actions, values are arrays as returned by
2821          *     Title::getRestrictions()
2822          * @since 1.23
2823          */
2824         public function getAllRestrictions() {
2825                 if ( !$this->mRestrictionsLoaded ) {
2826                         $this->loadRestrictions();
2827                 }
2828                 return $this->mRestrictions;
2829         }
2830
2831         /**
2832          * Get the expiry time for the restriction against a given action
2833          *
2834          * @param string $action
2835          * @return string|bool 14-char timestamp, or 'infinity' if the page is protected forever
2836          *     or not protected at all, or false if the action is not recognised.
2837          */
2838         public function getRestrictionExpiry( $action ) {
2839                 if ( !$this->mRestrictionsLoaded ) {
2840                         $this->loadRestrictions();
2841                 }
2842                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2843         }
2844
2845         /**
2846          * Returns cascading restrictions for the current article
2847          *
2848          * @return bool
2849          */
2850         function areRestrictionsCascading() {
2851                 if ( !$this->mRestrictionsLoaded ) {
2852                         $this->loadRestrictions();
2853                 }
2854
2855                 return $this->mCascadeRestriction;
2856         }
2857
2858         /**
2859          * Loads a string into mRestrictions array
2860          *
2861          * @param ResultWrapper $res Resource restrictions as an SQL result.
2862          * @param string $oldFashionedRestrictions Comma-separated list of page
2863          *        restrictions from page table (pre 1.10)
2864          */
2865         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2866                 $rows = [];
2867
2868                 foreach ( $res as $row ) {
2869                         $rows[] = $row;
2870                 }
2871
2872                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2873         }
2874
2875         /**
2876          * Compiles list of active page restrictions from both page table (pre 1.10)
2877          * and page_restrictions table for this existing page.
2878          * Public for usage by LiquidThreads.
2879          *
2880          * @param array $rows Array of db result objects
2881          * @param string $oldFashionedRestrictions Comma-separated list of page
2882          *   restrictions from page table (pre 1.10)
2883          */
2884         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2885                 $dbr = wfGetDB( DB_SLAVE );
2886
2887                 $restrictionTypes = $this->getRestrictionTypes();
2888
2889                 foreach ( $restrictionTypes as $type ) {
2890                         $this->mRestrictions[$type] = [];
2891                         $this->mRestrictionsExpiry[$type] = 'infinity';
2892                 }
2893
2894                 $this->mCascadeRestriction = false;
2895
2896                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2897                 if ( $oldFashionedRestrictions !== null ) {
2898                         $this->mOldRestrictions = $oldFashionedRestrictions;
2899                 }
2900
2901                 if ( $this->mOldRestrictions === false ) {
2902                         $this->mOldRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2903                                 [ 'page_id' => $this->getArticleID() ], __METHOD__ );
2904                 }
2905
2906                 if ( $this->mOldRestrictions != '' ) {
2907                         foreach ( explode( ':', trim( $this->mOldRestrictions ) ) as $restrict ) {
2908                                 $temp = explode( '=', trim( $restrict ) );
2909                                 if ( count( $temp ) == 1 ) {
2910                                         // old old format should be treated as edit/move restriction
2911                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2912                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2913                                 } else {
2914                                         $restriction = trim( $temp[1] );
2915                                         if ( $restriction != '' ) { // some old entries are empty
2916                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2917                                         }
2918                                 }
2919                         }
2920                 }
2921
2922                 if ( count( $rows ) ) {
2923                         # Current system - load second to make them override.
2924                         $now = wfTimestampNow();
2925
2926                         # Cycle through all the restrictions.
2927                         foreach ( $rows as $row ) {
2928
2929                                 // Don't take care of restrictions types that aren't allowed
2930                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2931                                         continue;
2932                                 }
2933
2934                                 // This code should be refactored, now that it's being used more generally,
2935                                 // But I don't really see any harm in leaving it in Block for now -werdna
2936                                 $expiry = $dbr->decodeExpiry( $row->pr_expiry );
2937
2938                                 // Only apply the restrictions if they haven't expired!
2939                                 if ( !$expiry || $expiry > $now ) {
2940                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2941                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2942
2943                                         $this->mCascadeRestriction |= $row->pr_cascade;
2944                                 }
2945                         }
2946                 }
2947
2948                 $this->mRestrictionsLoaded = true;
2949         }
2950
2951         /**
2952          * Load restrictions from the page_restrictions table
2953          *
2954          * @param string $oldFashionedRestrictions Comma-separated list of page
2955          *   restrictions from page table (pre 1.10)
2956          */
2957         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2958                 if ( !$this->mRestrictionsLoaded ) {
2959                         $dbr = wfGetDB( DB_SLAVE );
2960                         if ( $this->exists() ) {
2961                                 $res = $dbr->select(
2962                                         'page_restrictions',
2963                                         [ 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ],
2964                                         [ 'pr_page' => $this->getArticleID() ],
2965                                         __METHOD__
2966                                 );
2967
2968                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2969                         } else {
2970                                 $title_protection = $this->getTitleProtection();
2971
2972                                 if ( $title_protection ) {
2973                                         $now = wfTimestampNow();
2974                                         $expiry = $dbr->decodeExpiry( $title_protection['expiry'] );
2975
2976                                         if ( !$expiry || $expiry > $now ) {
2977                                                 // Apply the restrictions
2978                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2979                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['permission'] ) );
2980                                         } else { // Get rid of the old restrictions
2981                                                 $this->mTitleProtection = false;
2982                                         }
2983                                 } else {
2984                                         $this->mRestrictionsExpiry['create'] = 'infinity';
2985                                 }
2986                                 $this->mRestrictionsLoaded = true;
2987                         }
2988                 }
2989         }
2990
2991         /**
2992          * Flush the protection cache in this object and force reload from the database.
2993          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2994          */
2995         public function flushRestrictions() {
2996                 $this->mRestrictionsLoaded = false;
2997                 $this->mTitleProtection = null;
2998         }
2999
3000         /**
3001          * Purge expired restrictions from the page_restrictions table
3002          */
3003         static function purgeExpiredRestrictions() {
3004                 if ( wfReadOnly() ) {
3005                         return;
3006                 }
3007
3008                 DeferredUpdates::addUpdate( new AtomicSectionUpdate(
3009                         wfGetDB( DB_MASTER ),
3010                         __METHOD__,
3011                         function ( IDatabase $dbw, $fname ) {
3012                                 $dbw->delete(
3013                                         'page_restrictions',
3014                                         [ 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ],
3015                                         $fname
3016                                 );
3017                                 $dbw->delete(
3018                                         'protected_titles',
3019                                         [ 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ],
3020                                         $fname
3021                                 );
3022                         }
3023                 ) );
3024         }
3025
3026         /**
3027          * Does this have subpages?  (Warning, usually requires an extra DB query.)
3028          *
3029          * @return bool
3030          */
3031         public function hasSubpages() {
3032                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
3033                         # Duh
3034                         return false;
3035                 }
3036
3037                 # We dynamically add a member variable for the purpose of this method
3038                 # alone to cache the result.  There's no point in having it hanging
3039                 # around uninitialized in every Title object; therefore we only add it
3040                 # if needed and don't declare it statically.
3041                 if ( $this->mHasSubpages === null ) {
3042                         $this->mHasSubpages = false;
3043                         $subpages = $this->getSubpages( 1 );
3044                         if ( $subpages instanceof TitleArray ) {
3045                                 $this->mHasSubpages = (bool)$subpages->count();
3046                         }
3047                 }
3048
3049                 return $this->mHasSubpages;
3050         }
3051
3052         /**
3053          * Get all subpages of this page.
3054          *
3055          * @param int $limit Maximum number of subpages to fetch; -1 for no limit
3056          * @return TitleArray|array TitleArray, or empty array if this page's namespace
3057          *  doesn't allow subpages
3058          */
3059         public function getSubpages( $limit = -1 ) {
3060                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3061                         return [];
3062                 }
3063
3064                 $dbr = wfGetDB( DB_SLAVE );
3065                 $conds['page_namespace'] = $this->getNamespace();
3066                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
3067                 $options = [];
3068                 if ( $limit > -1 ) {
3069                         $options['LIMIT'] = $limit;
3070                 }
3071                 $this->mSubpages = TitleArray::newFromResult(
3072                         $dbr->select( 'page',
3073                                 [ 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ],
3074                                 $conds,
3075                                 __METHOD__,
3076                                 $options
3077                         )
3078                 );
3079                 return $this->mSubpages;
3080         }
3081
3082         /**
3083          * Is there a version of this page in the deletion archive?
3084          *
3085          * @return int The number of archived revisions
3086          */
3087         public function isDeleted() {
3088                 if ( $this->getNamespace() < 0 ) {
3089                         $n = 0;
3090                 } else {
3091                         $dbr = wfGetDB( DB_SLAVE );
3092
3093                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
3094                                 [ 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ],
3095                                 __METHOD__
3096                         );
3097                         if ( $this->getNamespace() == NS_FILE ) {
3098                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3099                                         [ 'fa_name' => $this->getDBkey() ],
3100                                         __METHOD__
3101                                 );
3102                         }
3103                 }
3104                 return (int)$n;
3105         }
3106
3107         /**
3108          * Is there a version of this page in the deletion archive?
3109          *
3110          * @return bool
3111          */
3112         public function isDeletedQuick() {
3113                 if ( $this->getNamespace() < 0 ) {
3114                         return false;
3115                 }
3116                 $dbr = wfGetDB( DB_SLAVE );
3117                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3118                         [ 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ],
3119                         __METHOD__
3120                 );
3121                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3122                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3123                                 [ 'fa_name' => $this->getDBkey() ],
3124                                 __METHOD__
3125                         );
3126                 }
3127                 return $deleted;
3128         }
3129
3130         /**
3131          * Get the article ID for this Title from the link cache,
3132          * adding it if necessary
3133          *
3134          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select
3135          *  for update
3136          * @return int The ID
3137          */
3138         public function getArticleID( $flags = 0 ) {
3139                 if ( $this->getNamespace() < 0 ) {
3140                         $this->mArticleID = 0;
3141                         return $this->mArticleID;
3142                 }
3143                 $linkCache = LinkCache::singleton();
3144                 if ( $flags & self::GAID_FOR_UPDATE ) {
3145                         $oldUpdate = $linkCache->forUpdate( true );
3146                         $linkCache->clearLink( $this );
3147                         $this->mArticleID = $linkCache->addLinkObj( $this );
3148                         $linkCache->forUpdate( $oldUpdate );
3149                 } else {
3150                         if ( -1 == $this->mArticleID ) {
3151                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3152                         }
3153                 }
3154                 return $this->mArticleID;
3155         }
3156
3157         /**
3158          * Is this an article that is a redirect page?
3159          * Uses link cache, adding it if necessary
3160          *
3161          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3162          * @return bool
3163          */
3164         public function isRedirect( $flags = 0 ) {
3165                 if ( !is_null( $this->mRedirect ) ) {
3166                         return $this->mRedirect;
3167                 }
3168                 if ( !$this->getArticleID( $flags ) ) {
3169                         $this->mRedirect = false;
3170                         return $this->mRedirect;
3171                 }
3172
3173                 $linkCache = LinkCache::singleton();
3174                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3175                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3176                 if ( $cached === null ) {
3177                         # Trust LinkCache's state over our own
3178                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3179                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3180                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3181                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3182                         # LinkCache to refresh its data from the master.
3183                         $this->mRedirect = false;
3184                         return $this->mRedirect;
3185                 }
3186
3187                 $this->mRedirect = (bool)$cached;
3188
3189                 return $this->mRedirect;
3190         }
3191
3192         /**
3193          * What is the length of this page?
3194          * Uses link cache, adding it if necessary
3195          *
3196          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3197          * @return int
3198          */
3199         public function getLength( $flags = 0 ) {
3200                 if ( $this->mLength != -1 ) {
3201                         return $this->mLength;
3202                 }
3203                 if ( !$this->getArticleID( $flags ) ) {
3204                         $this->mLength = 0;
3205                         return $this->mLength;
3206                 }
3207                 $linkCache = LinkCache::singleton();
3208                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3209                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3210                 if ( $cached === null ) {
3211                         # Trust LinkCache's state over our own, as for isRedirect()
3212                         $this->mLength = 0;
3213                         return $this->mLength;
3214                 }
3215
3216                 $this->mLength = intval( $cached );
3217
3218                 return $this->mLength;
3219         }
3220
3221         /**
3222          * What is the page_latest field for this page?
3223          *
3224          * @param int $flags A bit field; may be Title::GAID_FOR_UPDATE to select for update
3225          * @return int Int or 0 if the page doesn't exist
3226          */
3227         public function getLatestRevID( $flags = 0 ) {
3228                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3229                         return intval( $this->mLatestID );
3230                 }
3231                 if ( !$this->getArticleID( $flags ) ) {
3232                         $this->mLatestID = 0;
3233                         return $this->mLatestID;
3234                 }
3235                 $linkCache = LinkCache::singleton();
3236                 $linkCache->addLinkObj( $this ); # in case we already had an article ID
3237                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3238                 if ( $cached === null ) {
3239                         # Trust LinkCache's state over our own, as for isRedirect()
3240                         $this->mLatestID = 0;
3241                         return $this->mLatestID;
3242                 }
3243
3244                 $this->mLatestID = intval( $cached );
3245
3246                 return $this->mLatestID;
3247         }
3248
3249         /**
3250          * This clears some fields in this object, and clears any associated
3251          * keys in the "bad links" section of the link cache.
3252          *
3253          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3254          * loading of the new page_id. It's also called from
3255          * WikiPage::doDeleteArticleReal()
3256          *
3257          * @param int $newid The new Article ID
3258          */
3259         public function resetArticleID( $newid ) {
3260                 $linkCache = LinkCache::singleton();
3261                 $linkCache->clearLink( $this );
3262
3263                 if ( $newid === false ) {
3264                         $this->mArticleID = -1;
3265                 } else {
3266                         $this->mArticleID = intval( $newid );
3267                 }
3268                 $this->mRestrictionsLoaded = false;
3269                 $this->mRestrictions = [];
3270                 $this->mOldRestrictions = false;
3271                 $this->mRedirect = null;
3272                 $this->mLength = -1;
3273                 $this->mLatestID = false;
3274                 $this->mContentModel = false;
3275                 $this->mEstimateRevisions = null;
3276                 $this->mPageLanguage = false;
3277                 $this->mDbPageLanguage = false;
3278                 $this->mIsBigDeletion = null;
3279         }
3280
3281         public static function clearCaches() {
3282                 $linkCache = LinkCache::singleton();
3283                 $linkCache->clear();
3284
3285                 $titleCache = self::getTitleCache();
3286                 $titleCache->clear();
3287         }
3288
3289         /**
3290          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3291          *
3292          * @param string $text Containing title to capitalize
3293          * @param int $ns Namespace index, defaults to NS_MAIN
3294          * @return string Containing capitalized title
3295          */
3296         public static function capitalize( $text, $ns = NS_MAIN ) {
3297                 global $wgContLang;
3298
3299                 if ( MWNamespace::isCapitalized( $ns ) ) {
3300                         return $wgContLang->ucfirst( $text );
3301                 } else {
3302                         return $text;
3303                 }
3304         }
3305
3306         /**
3307          * Secure and split - main initialisation function for this object
3308          *
3309          * Assumes that mDbkeyform has been set, and is urldecoded
3310          * and uses underscores, but not otherwise munged.  This function
3311          * removes illegal characters, splits off the interwiki and
3312          * namespace prefixes, sets the other forms, and canonicalizes
3313          * everything.
3314          *
3315          * @throws MalformedTitleException On invalid titles
3316          * @return bool True on success
3317          */
3318         private function secureAndSplit() {
3319                 # Initialisation
3320                 $this->mInterwiki = '';
3321                 $this->mFragment = '';
3322                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3323
3324                 $dbkey = $this->mDbkeyform;
3325
3326                 // @note: splitTitleString() is a temporary hack to allow MediaWikiTitleCodec to share
3327                 //        the parsing code with Title, while avoiding massive refactoring.
3328                 // @todo: get rid of secureAndSplit, refactor parsing code.
3329                 $titleParser = self::getMediaWikiTitleCodec();
3330                 // MalformedTitleException can be thrown here
3331                 $parts = $titleParser->splitTitleString( $dbkey, $this->getDefaultNamespace() );
3332
3333                 # Fill fields
3334                 $this->setFragment( '#' . $parts['fragment'] );
3335                 $this->mInterwiki = $parts['interwiki'];
3336                 $this->mLocalInterwiki = $parts['local_interwiki'];
3337                 $this->mNamespace = $parts['namespace'];
3338                 $this->mUserCaseDBKey = $parts['user_case_dbkey'];
3339
3340                 $this->mDbkeyform = $parts['dbkey'];
3341                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
3342                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
3343
3344                 # We already know that some pages won't be in the database!
3345                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3346                         $this->mArticleID = 0;
3347                 }
3348
3349                 return true;
3350         }
3351
3352         /**
3353          * Get an array of Title objects linking to this Title
3354          * Also stores the IDs in the link cache.
3355          *
3356          * WARNING: do not use this function on arbitrary user-supplied titles!
3357          * On heavily-used templates it will max out the memory.
3358          *
3359          * @param array $options May be FOR UPDATE
3360          * @param string $table Table name
3361          * @param string $prefix Fields prefix
3362          * @return Title[] Array of Title objects linking here
3363          */
3364         public function getLinksTo( $options = [], $table = 'pagelinks', $prefix = 'pl' ) {
3365                 if ( count( $options ) > 0 ) {
3366                         $db = wfGetDB( DB_MASTER );
3367                 } else {
3368                         $db = wfGetDB( DB_SLAVE );
3369                 }
3370
3371                 $res = $db->select(
3372                         [ 'page', $table ],
3373                         self::getSelectFields(),
3374                         [
3375                                 "{$prefix}_from=page_id",
3376                                 "{$prefix}_namespace" => $this->getNamespace(),
3377                                 "{$prefix}_title" => $this->getDBkey() ],
3378                         __METHOD__,
3379                         $options
3380                 );
3381
3382                 $retVal = [];
3383                 if ( $res->numRows() ) {
3384                         $linkCache = LinkCache::singleton();
3385                         foreach ( $res as $row ) {
3386                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3387                                 if ( $titleObj ) {
3388                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3389                                         $retVal[] = $titleObj;
3390                                 }
3391                         }
3392                 }
3393                 return $retVal;
3394         }
3395
3396         /**
3397          * Get an array of Title objects using this Title as a template
3398          * Also stores the IDs in the link cache.
3399          *
3400          * WARNING: do not use this function on arbitrary user-supplied titles!
3401          * On heavily-used templates it will max out the memory.
3402          *
3403          * @param array $options Query option to Database::select()
3404          * @return Title[] Array of Title the Title objects linking here
3405          */
3406         public function getTemplateLinksTo( $options = [] ) {
3407                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3408         }
3409
3410         /**
3411          * Get an array of Title objects linked from this Title
3412          * Also stores the IDs in the link cache.
3413          *
3414          * WARNING: do not use this function on arbitrary user-supplied titles!
3415          * On heavily-used templates it will max out the memory.
3416          *
3417          * @param array $options Query option to Database::select()
3418          * @param string $table Table name
3419          * @param string $prefix Fields prefix
3420          * @return array Array of Title objects linking here
3421          */
3422         public function getLinksFrom( $options = [], $table = 'pagelinks', $prefix = 'pl' ) {
3423                 $id = $this->getArticleID();
3424
3425                 # If the page doesn't exist; there can't be any link from this page
3426                 if ( !$id ) {
3427                         return [];
3428                 }
3429
3430                 $db = wfGetDB( DB_SLAVE );
3431
3432                 $blNamespace = "{$prefix}_namespace";
3433                 $blTitle = "{$prefix}_title";
3434
3435                 $res = $db->select(
3436                         [ $table, 'page' ],
3437                         array_merge(
3438                                 [ $blNamespace, $blTitle ],
3439                                 WikiPage::selectFields()
3440                         ),
3441                         [ "{$prefix}_from" => $id ],
3442                         __METHOD__,
3443                         $options,
3444                         [ 'page' => [
3445                                 'LEFT JOIN',
3446                                 [ "page_namespace=$blNamespace", "page_title=$blTitle" ]
3447                         ] ]
3448                 );
3449
3450                 $retVal = [];
3451                 $linkCache = LinkCache::singleton();
3452                 foreach ( $res as $row ) {
3453                         if ( $row->page_id ) {
3454                                 $titleObj = Title::newFromRow( $row );
3455                         } else {
3456                                 $titleObj = Title::makeTitle( $row->$blNamespace, $row->$blTitle );
3457                                 $linkCache->addBadLinkObj( $titleObj );
3458                         }
3459                         $retVal[] = $titleObj;
3460                 }
3461
3462                 return $retVal;
3463         }
3464
3465         /**
3466          * Get an array of Title objects used on this Title as a template
3467          * Also stores the IDs in the link cache.
3468          *
3469          * WARNING: do not use this function on arbitrary user-supplied titles!
3470          * On heavily-used templates it will max out the memory.
3471          *
3472          * @param array $options May be FOR UPDATE
3473          * @return Title[] Array of Title the Title objects used here
3474          */
3475         public function getTemplateLinksFrom( $options = [] ) {
3476                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3477         }
3478
3479         /**
3480          * Get an array of Title objects referring to non-existent articles linked
3481          * from this page.
3482          *
3483          * @todo check if needed (used only in SpecialBrokenRedirects.php, and
3484          *   should use redirect table in this case).
3485          * @return Title[] Array of Title the Title objects
3486          */
3487         public function getBrokenLinksFrom() {
3488                 if ( $this->getArticleID() == 0 ) {
3489                         # All links from article ID 0 are false positives
3490                         return [];
3491                 }
3492
3493                 $dbr = wfGetDB( DB_SLAVE );
3494                 $res = $dbr->select(
3495                         [ 'page', 'pagelinks' ],
3496                         [ 'pl_namespace', 'pl_title' ],
3497                         [
3498                                 'pl_from' => $this->getArticleID(),
3499                                 'page_namespace IS NULL'
3500                         ],
3501                         __METHOD__, [],
3502                         [
3503                                 'page' => [
3504                                         'LEFT JOIN',
3505                                         [ 'pl_namespace=page_namespace', 'pl_title=page_title' ]
3506                                 ]
3507                         ]
3508                 );
3509
3510                 $retVal = [];
3511                 foreach ( $res as $row ) {
3512                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3513                 }
3514                 return $retVal;
3515         }
3516
3517         /**
3518          * Get a list of URLs to purge from the CDN cache when this
3519          * page changes
3520          *
3521          * @return string[] Array of String the URLs
3522          */
3523         public function getCdnUrls() {
3524                 $urls = [
3525                         $this->getInternalURL(),
3526                         $this->getInternalURL( 'action=history' )
3527                 ];
3528
3529                 $pageLang = $this->getPageLanguage();
3530                 if ( $pageLang->hasVariants() ) {
3531                         $variants = $pageLang->getVariants();
3532                         foreach ( $variants as $vCode ) {
3533                                 $urls[] = $this->getInternalURL( $vCode );
3534                         }
3535                 }
3536
3537                 // If we are looking at a css/js user subpage, purge the action=raw.
3538                 if ( $this->isJsSubpage() ) {
3539                         $urls[] = $this->getInternalURL( 'action=raw&ctype=text/javascript' );
3540                 } elseif ( $this->isCssSubpage() ) {
3541                         $urls[] = $this->getInternalURL( 'action=raw&ctype=text/css' );
3542                 }
3543
3544                 Hooks::run( 'TitleSquidURLs', [ $this, &$urls ] );
3545                 return $urls;
3546         }
3547
3548         /**
3549          * @deprecated since 1.27 use getCdnUrls()
3550          */
3551         public function getSquidURLs() {
3552                 return $this->getCdnUrls();
3553         }
3554
3555         /**
3556          * Purge all applicable CDN URLs
3557          */
3558         public function purgeSquid() {
3559                 DeferredUpdates::addUpdate(
3560                         new CdnCacheUpdate( $this->getCdnUrls() ),
3561                         DeferredUpdates::PRESEND
3562                 );
3563         }
3564
3565         /**
3566          * Move this page without authentication
3567          *
3568          * @deprecated since 1.25 use MovePage class instead
3569          * @param Title $nt The new page Title
3570          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3571          */
3572         public function moveNoAuth( &$nt ) {
3573                 wfDeprecated( __METHOD__, '1.25' );
3574                 return $this->moveTo( $nt, false );
3575         }
3576
3577         /**
3578          * Check whether a given move operation would be valid.
3579          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3580          *
3581          * @deprecated since 1.25, use MovePage's methods instead
3582          * @param Title $nt The new title
3583          * @param bool $auth Whether to check user permissions (uses $wgUser)
3584          * @param string $reason Is the log summary of the move, used for spam checking
3585          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3586          */
3587         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3588                 global $wgUser;
3589
3590                 if ( !( $nt instanceof Title ) ) {
3591                         // Normally we'd add this to $errors, but we'll get
3592                         // lots of syntax errors if $nt is not an object
3593                         return [ [ 'badtitletext' ] ];
3594                 }
3595
3596                 $mp = new MovePage( $this, $nt );
3597                 $errors = $mp->isValidMove()->getErrorsArray();
3598                 if ( $auth ) {
3599                         $errors = wfMergeErrorArrays(
3600                                 $errors,
3601                                 $mp->checkPermissions( $wgUser, $reason )->getErrorsArray()
3602                         );
3603                 }
3604
3605                 return $errors ?: true;
3606         }
3607
3608         /**
3609          * Check if the requested move target is a valid file move target
3610          * @todo move this to MovePage
3611          * @param Title $nt Target title
3612          * @return array List of errors
3613          */
3614         protected function validateFileMoveOperation( $nt ) {
3615                 global $wgUser;
3616
3617                 $errors = [];
3618
3619                 $destFile = wfLocalFile( $nt );
3620                 $destFile->load( File::READ_LATEST );
3621                 if ( !$wgUser->isAllowed( 'reupload-shared' )
3622                         && !$destFile->exists() && wfFindFile( $nt )
3623                 ) {
3624                         $errors[] = [ 'file-exists-sharedrepo' ];
3625                 }
3626
3627                 return $errors;
3628         }
3629
3630         /**
3631          * Move a title to a new location
3632          *
3633          * @deprecated since 1.25, use the MovePage class instead
3634          * @param Title $nt The new title
3635          * @param bool $auth Indicates whether $wgUser's permissions
3636          *  should be checked
3637          * @param string $reason The reason for the move
3638          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3639          *  Ignored if the user doesn't have the suppressredirect right.
3640          * @return array|bool True on success, getUserPermissionsErrors()-like array on failure
3641          */
3642         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3643                 global $wgUser;
3644                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3645                 if ( is_array( $err ) ) {
3646                         // Auto-block user's IP if the account was "hard" blocked
3647                         $wgUser->spreadAnyEditBlock();
3648                         return $err;
3649                 }
3650                 // Check suppressredirect permission
3651                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3652                         $createRedirect = true;
3653                 }
3654
3655                 $mp = new MovePage( $this, $nt );
3656                 $status = $mp->move( $wgUser, $reason, $createRedirect );
3657                 if ( $status->isOK() ) {
3658                         return true;
3659                 } else {
3660                         return $status->getErrorsArray();
3661                 }
3662         }
3663
3664         /**
3665          * Move this page's subpages to be subpages of $nt
3666          *
3667          * @param Title $nt Move target
3668          * @param bool $auth Whether $wgUser's permissions should be checked
3669          * @param string $reason The reason for the move
3670          * @param bool $createRedirect Whether to create redirects from the old subpages to
3671          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3672          * @return array Array with old page titles as keys, and strings (new page titles) or
3673          *     arrays (errors) as values, or an error array with numeric indices if no pages
3674          *     were moved
3675          */
3676         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3677                 global $wgMaximumMovedPages;
3678                 // Check permissions
3679                 if ( !$this->userCan( 'move-subpages' ) ) {
3680                         return [ 'cant-move-subpages' ];
3681                 }
3682                 // Do the source and target namespaces support subpages?
3683                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3684                         return [ 'namespace-nosubpages',
3685                                 MWNamespace::getCanonicalName( $this->getNamespace() ) ];
3686                 }
3687                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3688                         return [ 'namespace-nosubpages',
3689                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) ];
3690                 }
3691
3692                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3693                 $retval = [];
3694                 $count = 0;
3695                 foreach ( $subpages as $oldSubpage ) {
3696                         $count++;
3697                         if ( $count > $wgMaximumMovedPages ) {
3698                                 $retval[$oldSubpage->getPrefixedText()] =
3699                                                 [ 'movepage-max-pages',
3700                                                         $wgMaximumMovedPages ];
3701                                 break;
3702                         }
3703
3704                         // We don't know whether this function was called before
3705                         // or after moving the root page, so check both
3706                         // $this and $nt
3707                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
3708                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
3709                         ) {
3710                                 // When moving a page to a subpage of itself,
3711                                 // don't move it twice
3712                                 continue;
3713                         }
3714                         $newPageName = preg_replace(
3715                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3716                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3717                                         $oldSubpage->getDBkey() );
3718                         if ( $oldSubpage->isTalkPage() ) {
3719                                 $newNs = $nt->getTalkPage()->getNamespace();
3720                         } else {
3721                                 $newNs = $nt->getSubjectPage()->getNamespace();
3722                         }
3723                         # Bug 14385: we need makeTitleSafe because the new page names may
3724                         # be longer than 255 characters.
3725                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3726
3727                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3728                         if ( $success === true ) {
3729                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3730                         } else {
3731                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3732                         }
3733                 }
3734                 return $retval;
3735         }
3736
3737         /**
3738          * Checks if this page is just a one-rev redirect.
3739          * Adds lock, so don't use just for light purposes.
3740          *
3741          * @return bool
3742          */
3743         public function isSingleRevRedirect() {
3744                 global $wgContentHandlerUseDB;
3745
3746                 $dbw = wfGetDB( DB_MASTER );
3747
3748                 # Is it a redirect?
3749                 $fields = [ 'page_is_redirect', 'page_latest', 'page_id' ];
3750                 if ( $wgContentHandlerUseDB ) {
3751                         $fields[] = 'page_content_model';
3752                 }
3753
3754                 $row = $dbw->selectRow( 'page',
3755                         $fields,
3756                         $this->pageCond(),
3757                         __METHOD__,
3758                         [ 'FOR UPDATE' ]
3759                 );
3760                 # Cache some fields we may want
3761                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3762                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3763                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3764                 $this->mContentModel = $row && isset( $row->page_content_model )
3765                         ? strval( $row->page_content_model )
3766                         : false;
3767
3768                 if ( !$this->mRedirect ) {
3769                         return false;
3770                 }
3771                 # Does the article have a history?
3772                 $row = $dbw->selectField( [ 'page', 'revision' ],
3773                         'rev_id',
3774                         [ 'page_namespace' => $this->getNamespace(),
3775                                 'page_title' => $this->getDBkey(),
3776                                 'page_id=rev_page',
3777                                 'page_latest != rev_id'
3778                         ],
3779                         __METHOD__,
3780                         [ 'FOR UPDATE' ]
3781                 );
3782                 # Return true if there was no history
3783                 return ( $row === false );
3784         }
3785
3786         /**
3787          * Checks if $this can be moved to a given Title
3788          * - Selects for update, so don't call it unless you mean business
3789          *
3790          * @deprecated since 1.25, use MovePage's methods instead
3791          * @param Title $nt The new title to check
3792          * @return bool
3793          */
3794         public function isValidMoveTarget( $nt ) {
3795                 # Is it an existing file?
3796                 if ( $nt->getNamespace() == NS_FILE ) {
3797                         $file = wfLocalFile( $nt );
3798                         $file->load( File::READ_LATEST );
3799                         if ( $file->exists() ) {
3800                                 wfDebug( __METHOD__ . ": file exists\n" );
3801                                 return false;
3802                         }
3803                 }
3804                 # Is it a redirect with no history?
3805                 if ( !$nt->isSingleRevRedirect() ) {
3806                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3807                         return false;
3808                 }
3809                 # Get the article text
3810                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
3811                 if ( !is_object( $rev ) ) {
3812                         return false;
3813                 }
3814                 $content = $rev->getContent();
3815                 # Does the redirect point to the source?
3816                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3817                 $redirTitle = $content ? $content->getRedirectTarget() : null;
3818
3819                 if ( $redirTitle ) {
3820                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3821                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3822                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3823                                 return false;
3824                         } else {
3825                                 return true;
3826                         }
3827                 } else {
3828                         # Fail safe (not a redirect after all. strange.)
3829                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
3830                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
3831                         return false;
3832                 }
3833         }
3834
3835         /**
3836          * Get categories to which this Title belongs and return an array of
3837          * categories' names.
3838          *
3839          * @return array Array of parents in the form:
3840          *        $parent => $currentarticle
3841          */
3842         public function getParentCategories() {
3843                 global $wgContLang;
3844
3845                 $data = [];
3846
3847                 $titleKey = $this->getArticleID();
3848
3849                 if ( $titleKey === 0 ) {
3850                         return $data;
3851                 }
3852
3853                 $dbr = wfGetDB( DB_SLAVE );
3854
3855                 $res = $dbr->select(
3856                         'categorylinks',
3857                         'cl_to',
3858                         [ 'cl_from' => $titleKey ],
3859                         __METHOD__
3860                 );
3861
3862                 if ( $res->numRows() > 0 ) {
3863                         foreach ( $res as $row ) {
3864                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
3865                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3866                         }
3867                 }
3868                 return $data;
3869         }
3870
3871         /**
3872          * Get a tree of parent categories
3873          *
3874          * @param array $children Array with the children in the keys, to check for circular refs
3875          * @return array Tree of parent categories
3876          */
3877         public function getParentCategoryTree( $children = [] ) {
3878                 $stack = [];
3879                 $parents = $this->getParentCategories();
3880
3881                 if ( $parents ) {
3882                         foreach ( $parents as $parent => $current ) {
3883                                 if ( array_key_exists( $parent, $children ) ) {
3884                                         # Circular reference
3885                                         $stack[$parent] = [];
3886                                 } else {
3887                                         $nt = Title::newFromText( $parent );
3888                                         if ( $nt ) {
3889                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + [ $parent => 1 ] );
3890                                         }
3891                                 }
3892                         }
3893                 }
3894
3895                 return $stack;
3896         }
3897
3898         /**
3899          * Get an associative array for selecting this title from
3900          * the "page" table
3901          *
3902          * @return array Array suitable for the $where parameter of DB::select()
3903          */
3904         public function pageCond() {
3905                 if ( $this->mArticleID > 0 ) {
3906                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3907                         return [ 'page_id' => $this->mArticleID ];
3908                 } else {
3909                         return [ 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform ];
3910                 }
3911         }
3912
3913         /**
3914          * Get the revision ID of the previous revision
3915          *
3916          * @param int $revId Revision ID. Get the revision that was before this one.
3917          * @param int $flags Title::GAID_FOR_UPDATE
3918          * @return int|bool Old revision ID, or false if none exists
3919          */
3920         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3921                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3922                 $revId = $db->selectField( 'revision', 'rev_id',
3923                         [
3924                                 'rev_page' => $this->getArticleID( $flags ),
3925                                 'rev_id < ' . intval( $revId )
3926                         ],
3927                         __METHOD__,
3928                         [ 'ORDER BY' => 'rev_id DESC' ]
3929                 );
3930
3931                 if ( $revId === false ) {
3932                         return false;
3933                 } else {
3934                         return intval( $revId );
3935                 }
3936         }
3937
3938         /**
3939          * Get the revision ID of the next revision
3940          *
3941          * @param int $revId Revision ID. Get the revision that was after this one.
3942          * @param int $flags Title::GAID_FOR_UPDATE
3943          * @return int|bool Next revision ID, or false if none exists
3944          */
3945         public function getNextRevisionID( $revId, $flags = 0 ) {
3946                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3947                 $revId = $db->selectField( 'revision', 'rev_id',
3948                         [
3949                                 'rev_page' => $this->getArticleID( $flags ),
3950                                 'rev_id > ' . intval( $revId )
3951                         ],
3952                         __METHOD__,
3953                         [ 'ORDER BY' => 'rev_id' ]
3954                 );
3955
3956                 if ( $revId === false ) {
3957                         return false;
3958                 } else {
3959                         return intval( $revId );
3960                 }
3961         }
3962
3963         /**
3964          * Get the first revision of the page
3965          *
3966          * @param int $flags Title::GAID_FOR_UPDATE
3967          * @return Revision|null If page doesn't exist
3968          */
3969         public function getFirstRevision( $flags = 0 ) {
3970                 $pageId = $this->getArticleID( $flags );
3971                 if ( $pageId ) {
3972                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3973                         $row = $db->selectRow( 'revision', Revision::selectFields(),
3974                                 [ 'rev_page' => $pageId ],
3975                                 __METHOD__,
3976                                 [ 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 ]
3977                         );
3978                         if ( $row ) {
3979                                 return new Revision( $row );
3980                         }
3981                 }
3982                 return null;
3983         }
3984
3985         /**
3986          * Get the oldest revision timestamp of this page
3987          *
3988          * @param int $flags Title::GAID_FOR_UPDATE
3989          * @return string MW timestamp
3990          */
3991         public function getEarliestRevTime( $flags = 0 ) {
3992                 $rev = $this->getFirstRevision( $flags );
3993                 return $rev ? $rev->getTimestamp() : null;
3994         }
3995
3996         /**
3997          * Check if this is a new page
3998          *
3999          * @return bool
4000          */
4001         public function isNewPage() {
4002                 $dbr = wfGetDB( DB_SLAVE );
4003                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4004         }
4005
4006         /**
4007          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4008          *
4009          * @return bool
4010          */
4011         public function isBigDeletion() {
4012                 global $wgDeleteRevisionsLimit;
4013
4014                 if ( !$wgDeleteRevisionsLimit ) {
4015                         return false;
4016                 }
4017
4018                 if ( $this->mIsBigDeletion === null ) {
4019                         $dbr = wfGetDB( DB_SLAVE );
4020
4021                         $revCount = $dbr->selectRowCount(
4022                                 'revision',
4023                                 '1',
4024                                 [ 'rev_page' => $this->getArticleID() ],
4025                                 __METHOD__,
4026                                 [ 'LIMIT' => $wgDeleteRevisionsLimit + 1 ]
4027                         );
4028
4029                         $this->mIsBigDeletion = $revCount > $wgDeleteRevisionsLimit;
4030                 }
4031
4032                 return $this->mIsBigDeletion;
4033         }
4034
4035         /**
4036          * Get the approximate revision count of this page.
4037          *
4038          * @return int
4039          */
4040         public function estimateRevisionCount() {
4041                 if ( !$this->exists() ) {
4042                         return 0;
4043                 }
4044
4045                 if ( $this->mEstimateRevisions === null ) {
4046                         $dbr = wfGetDB( DB_SLAVE );
4047                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4048                                 [ 'rev_page' => $this->getArticleID() ], __METHOD__ );
4049                 }
4050
4051                 return $this->mEstimateRevisions;
4052         }
4053
4054         /**
4055          * Get the number of revisions between the given revision.
4056          * Used for diffs and other things that really need it.
4057          *
4058          * @param int|Revision $old Old revision or rev ID (first before range)
4059          * @param int|Revision $new New revision or rev ID (first after range)
4060          * @param int|null $max Limit of Revisions to count, will be incremented to detect truncations
4061          * @return int Number of revisions between these revisions.
4062          */
4063         public function countRevisionsBetween( $old, $new, $max = null ) {
4064                 if ( !( $old instanceof Revision ) ) {
4065                         $old = Revision::newFromTitle( $this, (int)$old );
4066                 }
4067                 if ( !( $new instanceof Revision ) ) {
4068                         $new = Revision::newFromTitle( $this, (int)$new );
4069                 }
4070                 if ( !$old || !$new ) {
4071                         return 0; // nothing to compare
4072                 }
4073                 $dbr = wfGetDB( DB_SLAVE );
4074                 $conds = [
4075                         'rev_page' => $this->getArticleID(),
4076                         'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4077                         'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4078                 ];
4079                 if ( $max !== null ) {
4080                         return $dbr->selectRowCount( 'revision', '1',
4081                                 $conds,
4082                                 __METHOD__,
4083                                 [ 'LIMIT' => $max + 1 ] // extra to detect truncation
4084                         );
4085                 } else {
4086                         return (int)$dbr->selectField( 'revision', 'count(*)', $conds, __METHOD__ );
4087                 }
4088         }
4089
4090         /**
4091          * Get the authors between the given revisions or revision IDs.
4092          * Used for diffs and other things that really need it.
4093          *
4094          * @since 1.23
4095          *
4096          * @param int|Revision $old Old revision or rev ID (first before range by default)
4097          * @param int|Revision $new New revision or rev ID (first after range by default)
4098          * @param int $limit Maximum number of authors
4099          * @param string|array $options (Optional): Single option, or an array of options:
4100          *     'include_old' Include $old in the range; $new is excluded.
4101          *     'include_new' Include $new in the range; $old is excluded.
4102          *     'include_both' Include both $old and $new in the range.
4103          *     Unknown option values are ignored.
4104          * @return array|null Names of revision authors in the range; null if not both revisions exist
4105          */
4106         public function getAuthorsBetween( $old, $new, $limit, $options = [] ) {
4107                 if ( !( $old instanceof Revision ) ) {
4108                         $old = Revision::newFromTitle( $this, (int)$old );
4109                 }
4110                 if ( !( $new instanceof Revision ) ) {
4111                         $new = Revision::newFromTitle( $this, (int)$new );
4112                 }
4113                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4114                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4115                 // in the sanity check below?
4116                 if ( !$old || !$new ) {
4117                         return null; // nothing to compare
4118                 }
4119                 $authors = [];
4120                 $old_cmp = '>';
4121                 $new_cmp = '<';
4122                 $options = (array)$options;
4123                 if ( in_array( 'include_old', $options ) ) {
4124                         $old_cmp = '>=';
4125                 }
4126                 if ( in_array( 'include_new', $options ) ) {
4127                         $new_cmp = '<=';
4128                 }
4129                 if ( in_array( 'include_both', $options ) ) {
4130                         $old_cmp = '>=';
4131                         $new_cmp = '<=';
4132                 }
4133                 // No DB query needed if $old and $new are the same or successive revisions:
4134                 if ( $old->getId() === $new->getId() ) {
4135                         return ( $old_cmp === '>' && $new_cmp === '<' ) ?
4136                                 [] :
4137                                 [ $old->getUserText( Revision::RAW ) ];
4138                 } elseif ( $old->getId() === $new->getParentId() ) {
4139                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4140                                 $authors[] = $old->getUserText( Revision::RAW );
4141                                 if ( $old->getUserText( Revision::RAW ) != $new->getUserText( Revision::RAW ) ) {
4142                                         $authors[] = $new->getUserText( Revision::RAW );
4143                                 }
4144                         } elseif ( $old_cmp === '>=' ) {
4145                                 $authors[] = $old->getUserText( Revision::RAW );
4146                         } elseif ( $new_cmp === '<=' ) {
4147                                 $authors[] = $new->getUserText( Revision::RAW );
4148                         }
4149                         return $authors;
4150                 }
4151                 $dbr = wfGetDB( DB_SLAVE );
4152                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4153                         [
4154                                 'rev_page' => $this->getArticleID(),
4155                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4156                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4157                         ], __METHOD__,
4158                         [ 'LIMIT' => $limit + 1 ] // add one so caller knows it was truncated
4159                 );
4160                 foreach ( $res as $row ) {
4161                         $authors[] = $row->rev_user_text;
4162                 }
4163                 return $authors;
4164         }
4165
4166         /**
4167          * Get the number of authors between the given revisions or revision IDs.
4168          * Used for diffs and other things that really need it.
4169          *
4170          * @param int|Revision $old Old revision or rev ID (first before range by default)
4171          * @param int|Revision $new New revision or rev ID (first after range by default)
4172          * @param int $limit Maximum number of authors
4173          * @param string|array $options (Optional): Single option, or an array of options:
4174          *     'include_old' Include $old in the range; $new is excluded.
4175          *     'include_new' Include $new in the range; $old is excluded.
4176          *     'include_both' Include both $old and $new in the range.
4177          *     Unknown option values are ignored.
4178          * @return int Number of revision authors in the range; zero if not both revisions exist
4179          */
4180         public function countAuthorsBetween( $old, $new, $limit, $options = [] ) {
4181                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4182                 return $authors ? count( $authors ) : 0;
4183         }
4184
4185         /**
4186          * Compare with another title.
4187          *
4188          * @param Title $title
4189          * @return bool
4190          */
4191         public function equals( Title $title ) {
4192                 // Note: === is necessary for proper matching of number-like titles.
4193                 return $this->getInterwiki() === $title->getInterwiki()
4194                         && $this->getNamespace() == $title->getNamespace()
4195                         && $this->getDBkey() === $title->getDBkey();
4196         }
4197
4198         /**
4199          * Check if this title is a subpage of another title
4200          *
4201          * @param Title $title
4202          * @return bool
4203          */
4204         public function isSubpageOf( Title $title ) {
4205                 return $this->getInterwiki() === $title->getInterwiki()
4206                         && $this->getNamespace() == $title->getNamespace()
4207                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4208         }
4209
4210         /**
4211          * Check if page exists.  For historical reasons, this function simply
4212          * checks for the existence of the title in the page table, and will
4213          * thus return false for interwiki links, special pages and the like.
4214          * If you want to know if a title can be meaningfully viewed, you should
4215          * probably call the isKnown() method instead.
4216          *
4217          * @param int $flags An optional bit field; may be Title::GAID_FOR_UPDATE to check
4218          *   from master/for update
4219          * @return bool
4220          */
4221         public function exists( $flags = 0 ) {
4222                 $exists = $this->getArticleID( $flags ) != 0;
4223                 Hooks::run( 'TitleExists', [ $this, &$exists ] );
4224                 return $exists;
4225         }
4226
4227         /**
4228          * Should links to this title be shown as potentially viewable (i.e. as
4229          * "bluelinks"), even if there's no record by this title in the page
4230          * table?
4231          *
4232          * This function is semi-deprecated for public use, as well as somewhat
4233          * misleadingly named.  You probably just want to call isKnown(), which
4234          * calls this function internally.
4235          *
4236          * (ISSUE: Most of these checks are cheap, but the file existence check
4237          * can potentially be quite expensive.  Including it here fixes a lot of
4238          * existing code, but we might want to add an optional parameter to skip
4239          * it and any other expensive checks.)
4240          *
4241          * @return bool
4242          */
4243         public function isAlwaysKnown() {
4244                 $isKnown = null;
4245
4246                 /**
4247                  * Allows overriding default behavior for determining if a page exists.
4248                  * If $isKnown is kept as null, regular checks happen. If it's
4249                  * a boolean, this value is returned by the isKnown method.
4250                  *
4251                  * @since 1.20
4252                  *
4253                  * @param Title $title
4254                  * @param bool|null $isKnown
4255                  */
4256                 Hooks::run( 'TitleIsAlwaysKnown', [ $this, &$isKnown ] );
4257
4258                 if ( !is_null( $isKnown ) ) {
4259                         return $isKnown;
4260                 }
4261
4262                 if ( $this->isExternal() ) {
4263                         return true;  // any interwiki link might be viewable, for all we know
4264                 }
4265
4266                 switch ( $this->mNamespace ) {
4267                         case NS_MEDIA:
4268                         case NS_FILE:
4269                                 // file exists, possibly in a foreign repo
4270                                 return (bool)wfFindFile( $this );
4271                         case NS_SPECIAL:
4272                                 // valid special page
4273                                 return SpecialPageFactory::exists( $this->getDBkey() );
4274                         case NS_MAIN:
4275                                 // selflink, possibly with fragment
4276                                 return $this->mDbkeyform == '';
4277                         case NS_MEDIAWIKI:
4278                                 // known system message
4279                                 return $this->hasSourceText() !== false;
4280                         default:
4281                                 return false;
4282                 }
4283         }
4284
4285         /**
4286          * Does this title refer to a page that can (or might) be meaningfully
4287          * viewed?  In particular, this function may be used to determine if
4288          * links to the title should be rendered as "bluelinks" (as opposed to
4289          * "redlinks" to non-existent pages).
4290          * Adding something else to this function will cause inconsistency
4291          * since LinkHolderArray calls isAlwaysKnown() and does its own
4292          * page existence check.
4293          *
4294          * @return bool
4295          */
4296         public function isKnown() {
4297                 return $this->isAlwaysKnown() || $this->exists();
4298         }
4299
4300         /**
4301          * Does this page have source text?
4302          *
4303          * @return bool
4304          */
4305         public function hasSourceText() {
4306                 if ( $this->exists() ) {
4307                         return true;
4308                 }
4309
4310                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4311                         // If the page doesn't exist but is a known system message, default
4312                         // message content will be displayed, same for language subpages-
4313                         // Use always content language to avoid loading hundreds of languages
4314                         // to get the link color.
4315                         global $wgContLang;
4316                         list( $name, ) = MessageCache::singleton()->figureMessage(
4317                                 $wgContLang->lcfirst( $this->getText() )
4318                         );
4319                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4320                         return $message->exists();
4321                 }
4322
4323                 return false;
4324         }
4325
4326         /**
4327          * Get the default message text or false if the message doesn't exist
4328          *
4329          * @return string|bool
4330          */
4331         public function getDefaultMessageText() {
4332                 global $wgContLang;
4333
4334                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4335                         return false;
4336                 }
4337
4338                 list( $name, $lang ) = MessageCache::singleton()->figureMessage(
4339                         $wgContLang->lcfirst( $this->getText() )
4340                 );
4341                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4342
4343                 if ( $message->exists() ) {
4344                         return $message->plain();
4345                 } else {
4346                         return false;
4347                 }
4348         }
4349
4350         /**
4351          * Updates page_touched for this page; called from LinksUpdate.php
4352          *
4353          * @param string $purgeTime [optional] TS_MW timestamp
4354          * @return bool True if the update succeeded
4355          */
4356         public function invalidateCache( $purgeTime = null ) {
4357                 if ( wfReadOnly() ) {
4358                         return false;
4359                 }
4360
4361                 if ( $this->mArticleID === 0 ) {
4362                         return true; // avoid gap locking if we know it's not there
4363                 }
4364
4365                 $method = __METHOD__;
4366                 $dbw = wfGetDB( DB_MASTER );
4367                 $conds = $this->pageCond();
4368                 $dbw->onTransactionIdle( function () use ( $dbw, $conds, $method, $purgeTime ) {
4369                         $dbTimestamp = $dbw->timestamp( $purgeTime ?: time() );
4370
4371                         $dbw->update(
4372                                 'page',
4373                                 [ 'page_touched' => $dbTimestamp ],
4374                                 $conds + [ 'page_touched < ' . $dbw->addQuotes( $dbTimestamp ) ],
4375                                 $method
4376                         );
4377                 } );
4378
4379                 return true;
4380         }
4381
4382         /**
4383          * Update page_touched timestamps and send CDN purge messages for
4384          * pages linking to this title. May be sent to the job queue depending
4385          * on the number of links. Typically called on create and delete.
4386          */
4387         public function touchLinks() {
4388                 DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'pagelinks' ) );
4389                 if ( $this->getNamespace() == NS_CATEGORY ) {
4390                         DeferredUpdates::addUpdate( new HTMLCacheUpdate( $this, 'categorylinks' ) );
4391                 }
4392         }
4393
4394         /**
4395          * Get the last touched timestamp
4396          *
4397          * @param IDatabase $db Optional db
4398          * @return string Last-touched timestamp
4399          */
4400         public function getTouched( $db = null ) {
4401                 if ( $db === null ) {
4402                         $db = wfGetDB( DB_SLAVE );
4403                 }
4404                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4405                 return $touched;
4406         }
4407
4408         /**
4409          * Get the timestamp when this page was updated since the user last saw it.
4410          *
4411          * @param User $user
4412          * @return string|null
4413          */
4414         public function getNotificationTimestamp( $user = null ) {
4415                 global $wgUser;
4416
4417                 // Assume current user if none given
4418                 if ( !$user ) {
4419                         $user = $wgUser;
4420                 }
4421                 // Check cache first
4422                 $uid = $user->getId();
4423                 if ( !$uid ) {
4424                         return false;
4425                 }
4426                 // avoid isset here, as it'll return false for null entries
4427                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4428                         return $this->mNotificationTimestamp[$uid];
4429                 }
4430                 // Don't cache too much!
4431                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4432                         $this->mNotificationTimestamp = [];
4433                 }
4434
4435                 $watchedItem = WatchedItemStore::getDefaultInstance()->getWatchedItem( $user, $this );
4436                 if ( $watchedItem ) {
4437                         $this->mNotificationTimestamp[$uid] = $watchedItem->getNotificationTimestamp();
4438                 } else {
4439                         $this->mNotificationTimestamp[$uid] = false;
4440                 }
4441
4442                 return $this->mNotificationTimestamp[$uid];
4443         }
4444
4445         /**
4446          * Generate strings used for xml 'id' names in monobook tabs
4447          *
4448          * @param string $prepend Defaults to 'nstab-'
4449          * @return string XML 'id' name
4450          */
4451         public function getNamespaceKey( $prepend = 'nstab-' ) {
4452                 global $wgContLang;
4453                 // Gets the subject namespace if this title
4454                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4455                 // Checks if canonical namespace name exists for namespace
4456                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4457                         // Uses canonical namespace name
4458                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4459                 } else {
4460                         // Uses text of namespace
4461                         $namespaceKey = $this->getSubjectNsText();
4462                 }
4463                 // Makes namespace key lowercase
4464                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4465                 // Uses main
4466                 if ( $namespaceKey == '' ) {
4467                         $namespaceKey = 'main';
4468                 }
4469                 // Changes file to image for backwards compatibility
4470                 if ( $namespaceKey == 'file' ) {
4471                         $namespaceKey = 'image';
4472                 }
4473                 return $prepend . $namespaceKey;
4474         }
4475
4476         /**
4477          * Get all extant redirects to this Title
4478          *
4479          * @param int|null $ns Single namespace to consider; null to consider all namespaces
4480          * @return Title[] Array of Title redirects to this title
4481          */
4482         public function getRedirectsHere( $ns = null ) {
4483                 $redirs = [];
4484
4485                 $dbr = wfGetDB( DB_SLAVE );
4486                 $where = [
4487                         'rd_namespace' => $this->getNamespace(),
4488                         'rd_title' => $this->getDBkey(),
4489                         'rd_from = page_id'
4490                 ];
4491                 if ( $this->isExternal() ) {
4492                         $where['rd_interwiki'] = $this->getInterwiki();
4493                 } else {
4494                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4495                 }
4496                 if ( !is_null( $ns ) ) {
4497                         $where['page_namespace'] = $ns;
4498                 }
4499
4500                 $res = $dbr->select(
4501                         [ 'redirect', 'page' ],
4502                         [ 'page_namespace', 'page_title' ],
4503                         $where,
4504                         __METHOD__
4505                 );
4506
4507                 foreach ( $res as $row ) {
4508                         $redirs[] = self::newFromRow( $row );
4509                 }
4510                 return $redirs;
4511         }
4512
4513         /**
4514          * Check if this Title is a valid redirect target
4515          *
4516          * @return bool
4517          */
4518         public function isValidRedirectTarget() {
4519                 global $wgInvalidRedirectTargets;
4520
4521                 if ( $this->isSpecialPage() ) {
4522                         // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4523                         if ( $this->isSpecial( 'Userlogout' ) ) {
4524                                 return false;
4525                         }
4526
4527                         foreach ( $wgInvalidRedirectTargets as $target ) {
4528                                 if ( $this->isSpecial( $target ) ) {
4529                                         return false;
4530                                 }
4531                         }
4532                 }
4533
4534                 return true;
4535         }
4536
4537         /**
4538          * Get a backlink cache object
4539          *
4540          * @return BacklinkCache
4541          */
4542         public function getBacklinkCache() {
4543                 return BacklinkCache::get( $this );
4544         }
4545
4546         /**
4547          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4548          *
4549          * @return bool
4550          */
4551         public function canUseNoindex() {
4552                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4553
4554                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4555                         ? $wgContentNamespaces
4556                         : $wgExemptFromUserRobotsControl;
4557
4558                 return !in_array( $this->mNamespace, $bannedNamespaces );
4559
4560         }
4561
4562         /**
4563          * Returns the raw sort key to be used for categories, with the specified
4564          * prefix.  This will be fed to Collation::getSortKey() to get a
4565          * binary sortkey that can be used for actual sorting.
4566          *
4567          * @param string $prefix The prefix to be used, specified using
4568          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4569          *   prefix.
4570          * @return string
4571          */
4572         public function getCategorySortkey( $prefix = '' ) {
4573                 $unprefixed = $this->getText();
4574
4575                 // Anything that uses this hook should only depend
4576                 // on the Title object passed in, and should probably
4577                 // tell the users to run updateCollations.php --force
4578                 // in order to re-sort existing category relations.
4579                 Hooks::run( 'GetDefaultSortkey', [ $this, &$unprefixed ] );
4580                 if ( $prefix !== '' ) {
4581                         # Separate with a line feed, so the unprefixed part is only used as
4582                         # a tiebreaker when two pages have the exact same prefix.
4583                         # In UCA, tab is the only character that can sort above LF
4584                         # so we strip both of them from the original prefix.
4585                         $prefix = strtr( $prefix, "\n\t", '  ' );
4586                         return "$prefix\n$unprefixed";
4587                 }
4588                 return $unprefixed;
4589         }
4590
4591         /**
4592          * Returns the page language code saved in the database, if $wgPageLanguageUseDB is set
4593          * to true in LocalSettings.php, otherwise returns false. If there is no language saved in
4594          * the db, it will return NULL.
4595          *
4596          * @return string|null|bool
4597          */
4598         private function getDbPageLanguageCode() {
4599                 global $wgPageLanguageUseDB;
4600
4601                 // check, if the page language could be saved in the database, and if so and
4602                 // the value is not requested already, lookup the page language using LinkCache
4603                 if ( $wgPageLanguageUseDB && $this->mDbPageLanguage === false ) {
4604                         $linkCache = LinkCache::singleton();
4605                         $linkCache->addLinkObj( $this );
4606                         $this->mDbPageLanguage = $linkCache->getGoodLinkFieldObj( $this, 'lang' );
4607                 }
4608
4609                 return $this->mDbPageLanguage;
4610         }
4611
4612         /**
4613          * Get the language in which the content of this page is written in
4614          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4615          * e.g. $wgLang (such as special pages, which are in the user language).
4616          *
4617          * @since 1.18
4618          * @return Language
4619          */
4620         public function getPageLanguage() {
4621                 global $wgLang, $wgLanguageCode;
4622                 if ( $this->isSpecialPage() ) {
4623                         // special pages are in the user language
4624                         return $wgLang;
4625                 }
4626
4627                 // Checking if DB language is set
4628                 $dbPageLanguage = $this->getDbPageLanguageCode();
4629                 if ( $dbPageLanguage ) {
4630                         return wfGetLangObj( $dbPageLanguage );
4631                 }
4632
4633                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4634                         // Note that this may depend on user settings, so the cache should
4635                         // be only per-request.
4636                         // NOTE: ContentHandler::getPageLanguage() may need to load the
4637                         // content to determine the page language!
4638                         // Checking $wgLanguageCode hasn't changed for the benefit of unit
4639                         // tests.
4640                         $contentHandler = ContentHandler::getForTitle( $this );
4641                         $langObj = $contentHandler->getPageLanguage( $this );
4642                         $this->mPageLanguage = [ $langObj->getCode(), $wgLanguageCode ];
4643                 } else {
4644                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4645                 }
4646
4647                 return $langObj;
4648         }
4649
4650         /**
4651          * Get the language in which the content of this page is written when
4652          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4653          * e.g. $wgLang (such as special pages, which are in the user language).
4654          *
4655          * @since 1.20
4656          * @return Language
4657          */
4658         public function getPageViewLanguage() {
4659                 global $wgLang;
4660
4661                 if ( $this->isSpecialPage() ) {
4662                         // If the user chooses a variant, the content is actually
4663                         // in a language whose code is the variant code.
4664                         $variant = $wgLang->getPreferredVariant();
4665                         if ( $wgLang->getCode() !== $variant ) {
4666                                 return Language::factory( $variant );
4667                         }
4668
4669                         return $wgLang;
4670                 }
4671
4672                 // Checking if DB language is set
4673                 $dbPageLanguage = $this->getDbPageLanguageCode();
4674                 if ( $dbPageLanguage ) {
4675                         $pageLang = wfGetLangObj( $dbPageLanguage );
4676                         $variant = $pageLang->getPreferredVariant();
4677                         if ( $pageLang->getCode() !== $variant ) {
4678                                 $pageLang = Language::factory( $variant );
4679                         }
4680
4681                         return $pageLang;
4682                 }
4683
4684                 // @note Can't be cached persistently, depends on user settings.
4685                 // @note ContentHandler::getPageViewLanguage() may need to load the
4686                 //   content to determine the page language!
4687                 $contentHandler = ContentHandler::getForTitle( $this );
4688                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4689                 return $pageLang;
4690         }
4691
4692         /**
4693          * Get a list of rendered edit notices for this page.
4694          *
4695          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4696          * they will already be wrapped in paragraphs.
4697          *
4698          * @since 1.21
4699          * @param int $oldid Revision ID that's being edited
4700          * @return array
4701          */
4702         public function getEditNotices( $oldid = 0 ) {
4703                 $notices = [];
4704
4705                 // Optional notice for the entire namespace
4706                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4707                 $msg = wfMessage( $editnotice_ns );
4708                 if ( $msg->exists() ) {
4709                         $html = $msg->parseAsBlock();
4710                         // Edit notices may have complex logic, but output nothing (T91715)
4711                         if ( trim( $html ) !== '' ) {
4712                                 $notices[$editnotice_ns] = Html::rawElement(
4713                                         'div',
4714                                         [ 'class' => [
4715                                                 'mw-editnotice',
4716                                                 'mw-editnotice-namespace',
4717                                                 Sanitizer::escapeClass( "mw-$editnotice_ns" )
4718                                         ] ],
4719                                         $html
4720                                 );
4721                         }
4722                 }
4723
4724                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4725                         // Optional notice for page itself and any parent page
4726                         $parts = explode( '/', $this->getDBkey() );
4727                         $editnotice_base = $editnotice_ns;
4728                         while ( count( $parts ) > 0 ) {
4729                                 $editnotice_base .= '-' . array_shift( $parts );
4730                                 $msg = wfMessage( $editnotice_base );
4731                                 if ( $msg->exists() ) {
4732                                         $html = $msg->parseAsBlock();
4733                                         if ( trim( $html ) !== '' ) {
4734                                                 $notices[$editnotice_base] = Html::rawElement(
4735                                                         'div',
4736                                                         [ 'class' => [
4737                                                                 'mw-editnotice',
4738                                                                 'mw-editnotice-base',
4739                                                                 Sanitizer::escapeClass( "mw-$editnotice_base" )
4740                                                         ] ],
4741                                                         $html
4742                                                 );
4743                                         }
4744                                 }
4745                         }
4746                 } else {
4747                         // Even if there are no subpages in namespace, we still don't want "/" in MediaWiki message keys
4748                         $editnoticeText = $editnotice_ns . '-' . strtr( $this->getDBkey(), '/', '-' );
4749                         $msg = wfMessage( $editnoticeText );
4750                         if ( $msg->exists() ) {
4751                                 $html = $msg->parseAsBlock();
4752                                 if ( trim( $html ) !== '' ) {
4753                                         $notices[$editnoticeText] = Html::rawElement(
4754                                                 'div',
4755                                                 [ 'class' => [
4756                                                         'mw-editnotice',
4757                                                         'mw-editnotice-page',
4758                                                         Sanitizer::escapeClass( "mw-$editnoticeText" )
4759                                                 ] ],
4760                                                 $html
4761                                         );
4762                                 }
4763                         }
4764                 }
4765
4766                 Hooks::run( 'TitleGetEditNotices', [ $this, $oldid, &$notices ] );
4767                 return $notices;
4768         }
4769
4770         /**
4771          * @return array
4772          */
4773         public function __sleep() {
4774                 return [
4775                         'mNamespace',
4776                         'mDbkeyform',
4777                         'mFragment',
4778                         'mInterwiki',
4779                         'mLocalInterwiki',
4780                         'mUserCaseDBKey',
4781                         'mDefaultNamespace',
4782                 ];
4783         }
4784
4785         public function __wakeup() {
4786                 $this->mArticleID = ( $this->mNamespace >= 0 ) ? -1 : 0;
4787                 $this->mUrlform = wfUrlencode( $this->mDbkeyform );
4788                 $this->mTextform = strtr( $this->mDbkeyform, '_', ' ' );
4789         }
4790
4791 }