includes/Title.php

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