includes/Title.php

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