includes/Title.php

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