includes/Title.php

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