includes/Title.php

   1 <?php
   2 /**
   3  * Representation 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  *
  31  * @internal documentation reviewed 15 Mar 2010
  32  */
  33 class Title {
  34         /** @var MapCacheLRU */
  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 $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  58         var $mUrlform = '';               // /< URL-encoded form of the main part
  59         var $mDbkeyform = '';             // /< Main part with underscores
  60         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  61         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  62         var $mInterwiki = '';             // /< Interwiki prefix
  63         var $mFragment = '';              // /< Title fragment (i.e. the bit after the #)
  64         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  65         var $mLatestID = false;           // /< ID of most recent revision
  66         var $mContentModel = false;       // /< ID of the page's content model, i.e. one of the CONTENT_MODEL_XXX constants
  67         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  68         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  69         var $mOldRestrictions = false;
  70         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  71         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  72         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  73         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  74         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  75         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  76         var $mPrefixedText = null;        ///< Text form including namespace/interwiki, initialised on demand
  77         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  78         # Don't change the following default, NS_MAIN is hardcoded in several
  79         # places.  See bug 696.
  80         # Zero except in {{transclusion}} tags
  81         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  82         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  83         var $mLength = -1;                // /< The page length, 0 for special pages
  84         var $mRedirect = null;            // /< Is the article at this title a redirect?
  85         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  86         var $mHasSubpage;                 // /< Whether a page has any subpages
  87         private $mPageLanguage = false;   // /< The (string) language code of the page's language and content code.
  88         // @}
  89
  90         /**
  91          * Constructor
  92          */
  93         /*protected*/ function __construct() { }
  94
  95         /**
  96          * Create a new Title from a prefixed DB key
  97          *
  98          * @param string $key the database key, which has underscores
  99          *      instead of spaces, possibly including namespace and
 100          *      interwiki prefixes
 101          * @return Title, or NULL on an error
 102          */
 103         public static function newFromDBkey( $key ) {
 104                 $t = new Title();
 105                 $t->mDbkeyform = $key;
 106                 if ( $t->secureAndSplit() ) {
 107                         return $t;
 108                 } else {
 109                         return null;
 110                 }
 111         }
 112
 113         /**
 114          * Create a new Title from text, such as what one would find in a link. De-
 115          * codes any HTML entities in the text.
 116          *
 117          * @param string $text the link text; spaces, prefixes, and an
 118          *   initial ':' indicating the main namespace are accepted.
 119          * @param int $defaultNamespace the namespace to use if none is specified
 120          *   by a prefix.  If you want to force a specific namespace even if
 121          *   $text might begin with a namespace prefix, use makeTitle() or
 122          *   makeTitleSafe().
 123          * @throws MWException
 124          * @return Title|null - Title or null on an error.
 125          */
 126         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 127                 if ( is_object( $text ) ) {
 128                         throw new MWException( 'Title::newFromText given an object' );
 129                 }
 130
 131                 $cache = self::getTitleCache();
 132
 133                 /**
 134                  * Wiki pages often contain multiple links to the same page.
 135                  * Title normalization and parsing can become expensive on
 136                  * pages with many links, so we can save a little time by
 137                  * caching them.
 138                  *
 139                  * In theory these are value objects and won't get changed...
 140                  */
 141                 if ( $defaultNamespace == NS_MAIN && $cache->has( $text ) ) {
 142                         return $cache->get( $text );
 143                 }
 144
 145                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 146                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 147
 148                 $t = new Title();
 149                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 150                 $t->mDefaultNamespace = $defaultNamespace;
 151
 152                 if ( $t->secureAndSplit() ) {
 153                         if ( $defaultNamespace == NS_MAIN ) {
 154                                 $cache->set( $text, $t );
 155                         }
 156                         return $t;
 157                 } else {
 158                         $ret = null;
 159                         return $ret;
 160                 }
 161         }
 162
 163         /**
 164          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 165          *
 166          * Example of wrong and broken code:
 167          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 168          *
 169          * Example of right code:
 170          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 171          *
 172          * Create a new Title from URL-encoded text. Ensures that
 173          * the given title's length does not exceed the maximum.
 174          *
 175          * @param string $url the title, as might be taken from a URL
 176          * @return Title the new object, or NULL on an error
 177          */
 178         public static function newFromURL( $url ) {
 179                 $t = new Title();
 180
 181                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 182                 # but some URLs used it as a space replacement and they still come
 183                 # from some external search tools.
 184                 if ( strpos( self::legalChars(), '+' ) === false ) {
 185                         $url = str_replace( '+', ' ', $url );
 186                 }
 187
 188                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 189                 if ( $t->secureAndSplit() ) {
 190                         return $t;
 191                 } else {
 192                         return null;
 193                 }
 194         }
 195
 196         /**
 197          * @return MapCacheLRU
 198          */
 199         private static function getTitleCache() {
 200                 if ( self::$titleCache == null ) {
 201                         self::$titleCache = new MapCacheLRU( self::CACHE_MAX );
 202                 }
 203                 return self::$titleCache;
 204         }
 205
 206         /**
 207          * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 208          * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
 209          *
 210          * @return array
 211          */
 212         protected static function getSelectFields() {
 213                 global $wgContentHandlerUseDB;
 214
 215                 $fields = array(
 216                         'page_namespace', 'page_title', 'page_id',
 217                         'page_len', 'page_is_redirect', 'page_latest',
 218                 );
 219
 220                 if ( $wgContentHandlerUseDB ) {
 221                         $fields[] = 'page_content_model';
 222                 }
 223
 224                 return $fields;
 225         }
 226
 227         /**
 228          * Create a new Title from an article ID
 229          *
 230          * @param int $id the page_id corresponding to the Title to create
 231          * @param int $flags use Title::GAID_FOR_UPDATE to use master
 232          * @return Title|null the new object, or NULL on an error
 233          */
 234         public static function newFromID( $id, $flags = 0 ) {
 235                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 236                 $row = $db->selectRow(
 237                         'page',
 238                         self::getSelectFields(),
 239                         array( 'page_id' => $id ),
 240                         __METHOD__
 241                 );
 242                 if ( $row !== false ) {
 243                         $title = Title::newFromRow( $row );
 244                 } else {
 245                         $title = null;
 246                 }
 247                 return $title;
 248         }
 249
 250         /**
 251          * Make an array of titles from an array of IDs
 252          *
 253          * @param array $ids of Int Array of IDs
 254          * @return Array of Titles
 255          */
 256         public static function newFromIDs( $ids ) {
 257                 if ( !count( $ids ) ) {
 258                         return array();
 259                 }
 260                 $dbr = wfGetDB( DB_SLAVE );
 261
 262                 $res = $dbr->select(
 263                         'page',
 264                         self::getSelectFields(),
 265                         array( 'page_id' => $ids ),
 266                         __METHOD__
 267                 );
 268
 269                 $titles = array();
 270                 foreach ( $res as $row ) {
 271                         $titles[] = Title::newFromRow( $row );
 272                 }
 273                 return $titles;
 274         }
 275
 276         /**
 277          * Make a Title object from a DB row
 278          *
 279          * @param stdClass $row Object database row (needs at least page_title,page_namespace)
 280          * @return Title corresponding Title
 281          */
 282         public static function newFromRow( $row ) {
 283                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 284                 $t->loadFromRow( $row );
 285                 return $t;
 286         }
 287
 288         /**
 289          * Load Title object fields from a DB row.
 290          * If false is given, the title will be treated as non-existing.
 291          *
 292          * @param $row stdClass|bool database row
 293          */
 294         public function loadFromRow( $row ) {
 295                 if ( $row ) { // page found
 296                         if ( isset( $row->page_id ) ) {
 297                                 $this->mArticleID = (int)$row->page_id;
 298                         }
 299                         if ( isset( $row->page_len ) ) {
 300                                 $this->mLength = (int)$row->page_len;
 301                         }
 302                         if ( isset( $row->page_is_redirect ) ) {
 303                                 $this->mRedirect = (bool)$row->page_is_redirect;
 304                         }
 305                         if ( isset( $row->page_latest ) ) {
 306                                 $this->mLatestID = (int)$row->page_latest;
 307                         }
 308                         if ( isset( $row->page_content_model ) ) {
 309                                 $this->mContentModel = strval( $row->page_content_model );
 310                         } else {
 311                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 312                         }
 313                 } else { // page not found
 314                         $this->mArticleID = 0;
 315                         $this->mLength = 0;
 316                         $this->mRedirect = false;
 317                         $this->mLatestID = 0;
 318                         $this->mContentModel = false; # initialized lazily in getContentModel()
 319                 }
 320         }
 321
 322         /**
 323          * Create a new Title from a namespace index and a DB key.
 324          * It's assumed that $ns and $title are *valid*, for instance when
 325          * they came directly from the database or a special page name.
 326          * For convenience, spaces are converted to underscores so that
 327          * eg user_text fields can be used directly.
 328          *
 329          * @param int $ns the namespace of the article
 330          * @param string $title the unprefixed database key form
 331          * @param string $fragment the link fragment (after the "#")
 332          * @param string $interwiki the interwiki prefix
 333          * @return Title the new object
 334          */
 335         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 336                 $t = new Title();
 337                 $t->mInterwiki = $interwiki;
 338                 $t->mFragment = $fragment;
 339                 $t->mNamespace = $ns = intval( $ns );
 340                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 341                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 342                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 343                 $t->mTextform = str_replace( '_', ' ', $title );
 344                 $t->mContentModel = false; # initialized lazily in getContentModel()
 345                 return $t;
 346         }
 347
 348         /**
 349          * Create a new Title from a namespace index and a DB key.
 350          * The parameters will be checked for validity, which is a bit slower
 351          * than makeTitle() but safer for user-provided data.
 352          *
 353          * @param int $ns the namespace of the article
 354          * @param string $title database key form
 355          * @param string $fragment the link fragment (after the "#")
 356          * @param string $interwiki interwiki prefix
 357          * @return Title the new object, or NULL on an error
 358          */
 359         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 360                 if ( !MWNamespace::exists( $ns ) ) {
 361                         return null;
 362                 }
 363
 364                 $t = new Title();
 365                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 366                 if ( $t->secureAndSplit() ) {
 367                         return $t;
 368                 } else {
 369                         return null;
 370                 }
 371         }
 372
 373         /**
 374          * Create a new Title for the Main Page
 375          *
 376          * @return Title the new object
 377          */
 378         public static function newMainPage() {
 379                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 380                 // Don't give fatal errors if the message is broken
 381                 if ( !$title ) {
 382                         $title = Title::newFromText( 'Main Page' );
 383                 }
 384                 return $title;
 385         }
 386
 387         /**
 388          * Extract a redirect destination from a string and return the
 389          * Title, or null if the text doesn't contain a valid redirect
 390          * This will only return the very next target, useful for
 391          * the redirect table and other checks that don't need full recursion
 392          *
 393          * @param string $text Text with possible redirect
 394          * @return Title: The corresponding Title
 395          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 396          */
 397         public static function newFromRedirect( $text ) {
 398                 ContentHandler::deprecated( __METHOD__, '1.21' );
 399
 400                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 401                 return $content->getRedirectTarget();
 402         }
 403
 404         /**
 405          * Extract a redirect destination from a string and return the
 406          * Title, or null if the text doesn't contain a valid redirect
 407          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 408          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 409          *
 410          * @param string $text Text with possible redirect
 411          * @return Title
 412          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 413          */
 414         public static function newFromRedirectRecurse( $text ) {
 415                 ContentHandler::deprecated( __METHOD__, '1.21' );
 416
 417                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 418                 return $content->getUltimateRedirectTarget();
 419         }
 420
 421         /**
 422          * Extract a redirect destination from a string and return an
 423          * array of Titles, or null if the text doesn't contain a valid redirect
 424          * The last element in the array is the final destination after all redirects
 425          * have been resolved (up to $wgMaxRedirects times)
 426          *
 427          * @param string $text Text with possible redirect
 428          * @return Array of Titles, with the destination last
 429          * @deprecated since 1.21, use Content::getRedirectChain instead.
 430          */
 431         public static function newFromRedirectArray( $text ) {
 432                 ContentHandler::deprecated( __METHOD__, '1.21' );
 433
 434                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 435                 return $content->getRedirectChain();
 436         }
 437
 438         /**
 439          * Get the prefixed DB key associated with an ID
 440          *
 441          * @param int $id the page_id of the article
 442          * @return Title an object representing the article, or NULL if no such article was found
 443          */
 444         public static function nameOf( $id ) {
 445                 $dbr = wfGetDB( DB_SLAVE );
 446
 447                 $s = $dbr->selectRow(
 448                         'page',
 449                         array( 'page_namespace', 'page_title' ),
 450                         array( 'page_id' => $id ),
 451                         __METHOD__
 452                 );
 453                 if ( $s === false ) {
 454                         return null;
 455                 }
 456
 457                 $n = self::makeName( $s->page_namespace, $s->page_title );
 458                 return $n;
 459         }
 460
 461         /**
 462          * Get a regex character class describing the legal characters in a link
 463          *
 464          * @return String the list of characters, not delimited
 465          */
 466         public static function legalChars() {
 467                 global $wgLegalTitleChars;
 468                 return $wgLegalTitleChars;
 469         }
 470
 471         /**
 472          * Returns a simple regex that will match on characters and sequences invalid in titles.
 473          * Note that this doesn't pick up many things that could be wrong with titles, but that
 474          * replacing this regex with something valid will make many titles valid.
 475          *
 476          * @return String regex string
 477          */
 478         static function getTitleInvalidRegex() {
 479                 static $rxTc = false;
 480                 if ( !$rxTc ) {
 481                         # Matching titles will be held as illegal.
 482                         $rxTc = '/' .
 483                                 # Any character not allowed is forbidden...
 484                                 '[^' . self::legalChars() . ']' .
 485                                 # URL percent encoding sequences interfere with the ability
 486                                 # to round-trip titles -- you can't link to them consistently.
 487                                 '|%[0-9A-Fa-f]{2}' .
 488                                 # XML/HTML character references produce similar issues.
 489                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 490                                 '|&#[0-9]+;' .
 491                                 '|&#x[0-9A-Fa-f]+;' .
 492                                 '/S';
 493                 }
 494
 495                 return $rxTc;
 496         }
 497
 498         /**
 499          * Utility method for converting a character sequence from bytes to Unicode.
 500          *
 501          * Primary usecase being converting $wgLegalTitleChars to a sequence usable in
 502          * javascript, as PHP uses UTF-8 bytes where javascript uses Unicode code units.
 503          *
 504          * @param string $byteClass
 505          * @return string
 506          */
 507         public static function convertByteClassToUnicodeClass( $byteClass ) {
 508                 $length = strlen( $byteClass );
 509                 // Input token queue
 510                 $x0 = $x1 = $x2 = '';
 511                 // Decoded queue
 512                 $d0 = $d1 = $d2 = '';
 513                 // Decoded integer codepoints
 514                 $ord0 = $ord1 = $ord2 = 0;
 515                 // Re-encoded queue
 516                 $r0 = $r1 = $r2 = '';
 517                 // Output
 518                 $out = '';
 519                 // Flags
 520                 $allowUnicode = false;
 521                 for ( $pos = 0; $pos < $length; $pos++ ) {
 522                         // Shift the queues down
 523                         $x2 = $x1;
 524                         $x1 = $x0;
 525                         $d2 = $d1;
 526                         $d1 = $d0;
 527                         $ord2 = $ord1;
 528                         $ord1 = $ord0;
 529                         $r2 = $r1;
 530                         $r1 = $r0;
 531                         // Load the current input token and decoded values
 532                         $inChar = $byteClass[$pos];
 533                         if ( $inChar == '\\' ) {
 534                                 if ( preg_match( '/x([0-9a-fA-F]{2})/A', $byteClass, $m, 0, $pos + 1 ) ) {
 535                                         $x0 = $inChar . $m[0];
 536                                         $d0 = chr( hexdec( $m[1] ) );
 537                                         $pos += strlen( $m[0] );
 538                                 } elseif ( preg_match( '/[0-7]{3}/A', $byteClass, $m, 0, $pos + 1 ) ) {
 539                                         $x0 = $inChar . $m[0];
 540                                         $d0 = chr( octdec( $m[0] ) );
 541                                         $pos += strlen( $m[0] );
 542                                 } elseif ( $pos + 1 >= $length ) {
 543                                         $x0 = $d0 = '\\';
 544                                 } else {
 545                                         $d0 = $byteClass[$pos + 1];
 546                                         $x0 = $inChar . $d0;
 547                                         $pos += 1;
 548                                 }
 549                         } else {
 550                                 $x0 = $d0 = $inChar;
 551                         }
 552                         $ord0 = ord( $d0 );
 553                         // Load the current re-encoded value
 554                         if ( $ord0 < 32 || $ord0 == 0x7f ) {
 555                                 $r0 = sprintf( '\x%02x', $ord0 );
 556                         } elseif ( $ord0 >= 0x80 ) {
 557                                 // Allow unicode if a single high-bit character appears
 558                                 $r0 = sprintf( '\x%02x', $ord0 );
 559                                 $allowUnicode = true;
 560                         } elseif ( strpos( '-\\[]^', $d0 ) !== false ) {
 561                                 $r0 = '\\' . $d0;
 562                         } else {
 563                                 $r0 = $d0;
 564                         }
 565                         // Do the output
 566                         if ( $x0 !== '' && $x1 === '-' && $x2 !== '' ) {
 567                                 // Range
 568                                 if ( $ord2 > $ord0 ) {
 569                                         // Empty range
 570                                 } elseif ( $ord0 >= 0x80 ) {
 571                                         // Unicode range
 572                                         $allowUnicode = true;
 573                                         if ( $ord2 < 0x80 ) {
 574                                                 // Keep the non-unicode section of the range
 575                                                 $out .= "$r2-\\x7F";
 576                                         }
 577                                 } else {
 578                                         // Normal range
 579                                         $out .= "$r2-$r0";
 580                                 }
 581                                 // Reset state to the initial value
 582                                 $x0 = $x1 = $d0 = $d1 = $r0 = $r1 = '';
 583                         } elseif ( $ord2 < 0x80 ) {
 584                                 // ASCII character
 585                                 $out .= $r2;
 586                         }
 587                 }
 588                 if ( $ord1 < 0x80 ) {
 589                         $out .= $r1;
 590                 }
 591                 if ( $ord0 < 0x80 ) {
 592                         $out .= $r0;
 593                 }
 594                 if ( $allowUnicode ) {
 595                         $out .= '\u0080-\uFFFF';
 596                 }
 597                 return $out;
 598         }
 599
 600         /**
 601          * Get a string representation of a title suitable for
 602          * including in a search index
 603          *
 604          * @param int $ns a namespace index
 605          * @param string $title text-form main part
 606          * @return String a stripped-down title string ready for the search index
 607          */
 608         public static function indexTitle( $ns, $title ) {
 609                 global $wgContLang;
 610
 611                 $lc = SearchEngine::legalSearchChars() . '&#;';
 612                 $t = $wgContLang->normalizeForSearch( $title );
 613                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 614                 $t = $wgContLang->lc( $t );
 615
 616                 # Handle 's, s'
 617                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 618                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 619
 620                 $t = preg_replace( "/\\s+/", ' ', $t );
 621
 622                 if ( $ns == NS_FILE ) {
 623                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 624                 }
 625                 return trim( $t );
 626         }
 627
 628         /**
 629          * Make a prefixed DB key from a DB key and a namespace index
 630          *
 631          * @param int $ns numerical representation of the namespace
 632          * @param string $title the DB key form the title
 633          * @param string $fragment The link fragment (after the "#")
 634          * @param string $interwiki The interwiki prefix
 635          * @return String the prefixed form of the title
 636          */
 637         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 638                 global $wgContLang;
 639
 640                 $namespace = $wgContLang->getNsText( $ns );
 641                 $name = $namespace == '' ? $title : "$namespace:$title";
 642                 if ( strval( $interwiki ) != '' ) {
 643                         $name = "$interwiki:$name";
 644                 }
 645                 if ( strval( $fragment ) != '' ) {
 646                         $name .= '#' . $fragment;
 647                 }
 648                 return $name;
 649         }
 650
 651         /**
 652          * Escape a text fragment, say from a link, for a URL
 653          *
 654          * @param string $fragment containing a URL or link fragment (after the "#")
 655          * @return String: escaped string
 656          */
 657         static function escapeFragmentForURL( $fragment ) {
 658                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 659                 # fragments appear not to work in IE (at least up to 7) or in at least
 660                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 661                 # to care if they aren't encoded.
 662                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 663         }
 664
 665         /**
 666          * Callback for usort() to do title sorts by (namespace, title)
 667          *
 668          * @param $a Title
 669          * @param $b Title
 670          *
 671          * @return Integer: result of string comparison, or namespace comparison
 672          */
 673         public static function compare( $a, $b ) {
 674                 if ( $a->getNamespace() == $b->getNamespace() ) {
 675                         return strcmp( $a->getText(), $b->getText() );
 676                 } else {
 677                         return $a->getNamespace() - $b->getNamespace();
 678                 }
 679         }
 680
 681         /**
 682          * Determine whether the object refers to a page within
 683          * this project.
 684          *
 685          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 686          */
 687         public function isLocal() {
 688                 if ( $this->isExternal() ) {
 689                         $iw = Interwiki::fetch( $this->mInterwiki );
 690                         if ( $iw ) {
 691                                 return $iw->isLocal();
 692                         }
 693                 }
 694                 return true;
 695         }
 696
 697         /**
 698          * Is this Title interwiki?
 699          *
 700          * @return Bool
 701          */
 702         public function isExternal() {
 703                 return $this->mInterwiki !== '';
 704         }
 705
 706         /**
 707          * Get the interwiki prefix
 708          *
 709          * Use Title::isExternal to check if a interwiki is set
 710          *
 711          * @return String Interwiki prefix
 712          */
 713         public function getInterwiki() {
 714                 return $this->mInterwiki;
 715         }
 716
 717         /**
 718          * Determine whether the object refers to a page within
 719          * this project and is transcludable.
 720          *
 721          * @return Bool TRUE if this is transcludable
 722          */
 723         public function isTrans() {
 724                 if ( !$this->isExternal() ) {
 725                         return false;
 726                 }
 727
 728                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 729         }
 730
 731         /**
 732          * Returns the DB name of the distant wiki which owns the object.
 733          *
 734          * @return String the DB name
 735          */
 736         public function getTransWikiID() {
 737                 if ( !$this->isExternal() ) {
 738                         return false;
 739                 }
 740
 741                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 742         }
 743
 744         /**
 745          * Get the text form (spaces not underscores) of the main part
 746          *
 747          * @return String Main part of the title
 748          */
 749         public function getText() {
 750                 return $this->mTextform;
 751         }
 752
 753         /**
 754          * Get the URL-encoded form of the main part
 755          *
 756          * @return String Main part of the title, URL-encoded
 757          */
 758         public function getPartialURL() {
 759                 return $this->mUrlform;
 760         }
 761
 762         /**
 763          * Get the main part with underscores
 764          *
 765          * @return String: Main part of the title, with underscores
 766          */
 767         public function getDBkey() {
 768                 return $this->mDbkeyform;
 769         }
 770
 771         /**
 772          * Get the DB key with the initial letter case as specified by the user
 773          *
 774          * @return String DB key
 775          */
 776         function getUserCaseDBKey() {
 777                 if ( !is_null( $this->mUserCaseDBKey ) ) {
 778                         return $this->mUserCaseDBKey;
 779                 } else {
 780                         // If created via makeTitle(), $this->mUserCaseDBKey is not set.
 781                         return $this->mDbkeyform;
 782                 }
 783         }
 784
 785         /**
 786          * Get the namespace index, i.e. one of the NS_xxxx constants.
 787          *
 788          * @return Integer: Namespace index
 789          */
 790         public function getNamespace() {
 791                 return $this->mNamespace;
 792         }
 793
 794         /**
 795          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 796          *
 797          * @throws MWException
 798          * @return String: Content model id
 799          */
 800         public function getContentModel() {
 801                 if ( !$this->mContentModel ) {
 802                         $linkCache = LinkCache::singleton();
 803                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 804                 }
 805
 806                 if ( !$this->mContentModel ) {
 807                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 808                 }
 809
 810                 if ( !$this->mContentModel ) {
 811                         throw new MWException( 'Failed to determine content model!' );
 812                 }
 813
 814                 return $this->mContentModel;
 815         }
 816
 817         /**
 818          * Convenience method for checking a title's content model name
 819          *
 820          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 821          * @return Boolean true if $this->getContentModel() == $id
 822          */
 823         public function hasContentModel( $id ) {
 824                 return $this->getContentModel() == $id;
 825         }
 826
 827         /**
 828          * Get the namespace text
 829          *
 830          * @return String: Namespace text
 831          */
 832         public function getNsText() {
 833                 global $wgContLang;
 834
 835                 if ( $this->isExternal() ) {
 836                         // This probably shouldn't even happen. ohh man, oh yuck.
 837                         // But for interwiki transclusion it sometimes does.
 838                         // Shit. Shit shit shit.
 839                         //
 840                         // Use the canonical namespaces if possible to try to
 841                         // resolve a foreign namespace.
 842                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 843                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 844                         }
 845                 }
 846
 847                 if ( $wgContLang->needsGenderDistinction() &&
 848                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 849                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 850                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 851                 }
 852
 853                 return $wgContLang->getNsText( $this->mNamespace );
 854         }
 855
 856         /**
 857          * Get the namespace text of the subject (rather than talk) page
 858          *
 859          * @return String Namespace text
 860          */
 861         public function getSubjectNsText() {
 862                 global $wgContLang;
 863                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 864         }
 865
 866         /**
 867          * Get the namespace text of the talk page
 868          *
 869          * @return String Namespace text
 870          */
 871         public function getTalkNsText() {
 872                 global $wgContLang;
 873                 return $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) );
 874         }
 875
 876         /**
 877          * Could this title have a corresponding talk page?
 878          *
 879          * @return Bool TRUE or FALSE
 880          */
 881         public function canTalk() {
 882                 return MWNamespace::canTalk( $this->mNamespace );
 883         }
 884
 885         /**
 886          * Is this in a namespace that allows actual pages?
 887          *
 888          * @return Bool
 889          * @internal note -- uses hardcoded namespace index instead of constants
 890          */
 891         public function canExist() {
 892                 return $this->mNamespace >= NS_MAIN;
 893         }
 894
 895         /**
 896          * Can this title be added to a user's watchlist?
 897          *
 898          * @return Bool TRUE or FALSE
 899          */
 900         public function isWatchable() {
 901                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 902         }
 903
 904         /**
 905          * Returns true if this is a special page.
 906          *
 907          * @return boolean
 908          */
 909         public function isSpecialPage() {
 910                 return $this->getNamespace() == NS_SPECIAL;
 911         }
 912
 913         /**
 914          * Returns true if this title resolves to the named special page
 915          *
 916          * @param string $name The special page name
 917          * @return boolean
 918          */
 919         public function isSpecial( $name ) {
 920                 if ( $this->isSpecialPage() ) {
 921                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 922                         if ( $name == $thisName ) {
 923                                 return true;
 924                         }
 925                 }
 926                 return false;
 927         }
 928
 929         /**
 930          * If the Title refers to a special page alias which is not the local default, resolve
 931          * the alias, and localise the name as necessary.  Otherwise, return $this
 932          *
 933          * @return Title
 934          */
 935         public function fixSpecialName() {
 936                 if ( $this->isSpecialPage() ) {
 937                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 938                         if ( $canonicalName ) {
 939                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 940                                 if ( $localName != $this->mDbkeyform ) {
 941                                         return Title::makeTitle( NS_SPECIAL, $localName );
 942                                 }
 943                         }
 944                 }
 945                 return $this;
 946         }
 947
 948         /**
 949          * Returns true if the title is inside the specified namespace.
 950          *
 951          * Please make use of this instead of comparing to getNamespace()
 952          * This function is much more resistant to changes we may make
 953          * to namespaces than code that makes direct comparisons.
 954          * @param int $ns The namespace
 955          * @return bool
 956          * @since 1.19
 957          */
 958         public function inNamespace( $ns ) {
 959                 return MWNamespace::equals( $this->getNamespace(), $ns );
 960         }
 961
 962         /**
 963          * Returns true if the title is inside one of the specified namespaces.
 964          *
 965          * @param ...$namespaces The namespaces to check for
 966          * @return bool
 967          * @since 1.19
 968          */
 969         public function inNamespaces( /* ... */ ) {
 970                 $namespaces = func_get_args();
 971                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 972                         $namespaces = $namespaces[0];
 973                 }
 974
 975                 foreach ( $namespaces as $ns ) {
 976                         if ( $this->inNamespace( $ns ) ) {
 977                                 return true;
 978                         }
 979                 }
 980
 981                 return false;
 982         }
 983
 984         /**
 985          * Returns true if the title has the same subject namespace as the
 986          * namespace specified.
 987          * For example this method will take NS_USER and return true if namespace
 988          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 989          * as their subject namespace.
 990          *
 991          * This is MUCH simpler than individually testing for equivalence
 992          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 993          * @since 1.19
 994          * @param $ns int
 995          * @return bool
 996          */
 997         public function hasSubjectNamespace( $ns ) {
 998                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 999         }
1000
1001         /**
1002          * Is this Title in a namespace which contains content?
1003          * In other words, is this a content page, for the purposes of calculating
1004          * statistics, etc?
1005          *
1006          * @return Boolean
1007          */
1008         public function isContentPage() {
1009                 return MWNamespace::isContent( $this->getNamespace() );
1010         }
1011
1012         /**
1013          * Would anybody with sufficient privileges be able to move this page?
1014          * Some pages just aren't movable.
1015          *
1016          * @return Bool TRUE or FALSE
1017          */
1018         public function isMovable() {
1019                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->isExternal() ) {
1020                         // Interwiki title or immovable namespace. Hooks don't get to override here
1021                         return false;
1022                 }
1023
1024                 $result = true;
1025                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
1026                 return $result;
1027         }
1028
1029         /**
1030          * Is this the mainpage?
1031          * @note Title::newFromText seems to be sufficiently optimized by the title
1032          * cache that we don't need to over-optimize by doing direct comparisons and
1033          * accidentally creating new bugs where $title->equals( Title::newFromText() )
1034          * ends up reporting something differently than $title->isMainPage();
1035          *
1036          * @since 1.18
1037          * @return Bool
1038          */
1039         public function isMainPage() {
1040                 return $this->equals( Title::newMainPage() );
1041         }
1042
1043         /**
1044          * Is this a subpage?
1045          *
1046          * @return Bool
1047          */
1048         public function isSubpage() {
1049                 return MWNamespace::hasSubpages( $this->mNamespace )
1050                         ? strpos( $this->getText(), '/' ) !== false
1051                         : false;
1052         }
1053
1054         /**
1055          * Is this a conversion table for the LanguageConverter?
1056          *
1057          * @return Bool
1058          */
1059         public function isConversionTable() {
1060                 // @todo ConversionTable should become a separate content model.
1061
1062                 return $this->getNamespace() == NS_MEDIAWIKI &&
1063                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
1064         }
1065
1066         /**
1067          * Does that page contain wikitext, or it is JS, CSS or whatever?
1068          *
1069          * @return Bool
1070          */
1071         public function isWikitextPage() {
1072                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
1073         }
1074
1075         /**
1076          * Could this page contain custom CSS or JavaScript for the global UI.
1077          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
1078          * or CONTENT_MODEL_JAVASCRIPT.
1079          *
1080          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
1081          *
1082          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
1083          *
1084          * @return Bool
1085          */
1086         public function isCssOrJsPage() {
1087                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
1088                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1089                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1090
1091                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
1092                 #      hook functions can force this method to return true even outside the mediawiki namespace.
1093
1094                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
1095
1096                 return $isCssOrJsPage;
1097         }
1098
1099         /**
1100          * Is this a .css or .js subpage of a user page?
1101          * @return Bool
1102          */
1103         public function isCssJsSubpage() {
1104                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1105                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1106                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1107         }
1108
1109         /**
1110          * Trim down a .css or .js subpage title to get the corresponding skin name
1111          *
1112          * @return string containing skin name from .css or .js subpage title
1113          */
1114         public function getSkinFromCssJsSubpage() {
1115                 $subpage = explode( '/', $this->mTextform );
1116                 $subpage = $subpage[count( $subpage ) - 1];
1117                 $lastdot = strrpos( $subpage, '.' );
1118                 if ( $lastdot === false ) {
1119                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1120                 }
1121                 return substr( $subpage, 0, $lastdot );
1122         }
1123
1124         /**
1125          * Is this a .css subpage of a user page?
1126          *
1127          * @return Bool
1128          */
1129         public function isCssSubpage() {
1130                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1131                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1132         }
1133
1134         /**
1135          * Is this a .js subpage of a user page?
1136          *
1137          * @return Bool
1138          */
1139         public function isJsSubpage() {
1140                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1141                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1142         }
1143
1144         /**
1145          * Is this a talk page of some sort?
1146          *
1147          * @return Bool
1148          */
1149         public function isTalkPage() {
1150                 return MWNamespace::isTalk( $this->getNamespace() );
1151         }
1152
1153         /**
1154          * Get a Title object associated with the talk page of this article
1155          *
1156          * @return Title the object for the talk page
1157          */
1158         public function getTalkPage() {
1159                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1160         }
1161
1162         /**
1163          * Get a title object associated with the subject page of this
1164          * talk page
1165          *
1166          * @return Title the object for the subject page
1167          */
1168         public function getSubjectPage() {
1169                 // Is this the same title?
1170                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1171                 if ( $this->getNamespace() == $subjectNS ) {
1172                         return $this;
1173                 }
1174                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1175         }
1176
1177         /**
1178          * Get the default namespace index, for when there is no namespace
1179          *
1180          * @return Int Default namespace index
1181          */
1182         public function getDefaultNamespace() {
1183                 return $this->mDefaultNamespace;
1184         }
1185
1186         /**
1187          * Get title for search index
1188          *
1189          * @return String a stripped-down title string ready for the
1190          *  search index
1191          */
1192         public function getIndexTitle() {
1193                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1194         }
1195
1196         /**
1197          * Get the Title fragment (i.e.\ the bit after the #) in text form
1198          *
1199          * Use Title::hasFragment to check for a fragment
1200          *
1201          * @return String Title fragment
1202          */
1203         public function getFragment() {
1204                 return $this->mFragment;
1205         }
1206
1207         /**
1208          * Check if a Title fragment is set
1209          *
1210          * @return bool
1211          * @since 1.23
1212          */
1213         public function hasFragment() {
1214                 return $this->mFragment !== '';
1215         }
1216
1217         /**
1218          * Get the fragment in URL form, including the "#" character if there is one
1219          * @return String Fragment in URL form
1220          */
1221         public function getFragmentForURL() {
1222                 if ( !$this->hasFragment() ) {
1223                         return '';
1224                 } else {
1225                         return '#' . Title::escapeFragmentForURL( $this->getFragment() );
1226                 }
1227         }
1228
1229         /**
1230          * Set the fragment for this title. Removes the first character from the
1231          * specified fragment before setting, so it assumes you're passing it with
1232          * an initial "#".
1233          *
1234          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1235          * Still in active use privately.
1236          *
1237          * @param string $fragment text
1238          */
1239         public function setFragment( $fragment ) {
1240                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1241         }
1242
1243         /**
1244          * Prefix some arbitrary text with the namespace or interwiki prefix
1245          * of this object
1246          *
1247          * @param string $name the text
1248          * @return String the prefixed text
1249          * @private
1250          */
1251         private function prefix( $name ) {
1252                 $p = '';
1253                 if ( $this->isExternal() ) {
1254                         $p = $this->mInterwiki . ':';
1255                 }
1256
1257                 if ( 0 != $this->mNamespace ) {
1258                         $p .= $this->getNsText() . ':';
1259                 }
1260                 return $p . $name;
1261         }
1262
1263         /**
1264          * Get the prefixed database key form
1265          *
1266          * @return String the prefixed title, with underscores and
1267          *  any interwiki and namespace prefixes
1268          */
1269         public function getPrefixedDBkey() {
1270                 $s = $this->prefix( $this->mDbkeyform );
1271                 $s = str_replace( ' ', '_', $s );
1272                 return $s;
1273         }
1274
1275         /**
1276          * Get the prefixed title with spaces.
1277          * This is the form usually used for display
1278          *
1279          * @return String the prefixed title, with spaces
1280          */
1281         public function getPrefixedText() {
1282                 if ( $this->mPrefixedText === null ) {
1283                         $s = $this->prefix( $this->mTextform );
1284                         $s = str_replace( '_', ' ', $s );
1285                         $this->mPrefixedText = $s;
1286                 }
1287                 return $this->mPrefixedText;
1288         }
1289
1290         /**
1291          * Return a string representation of this title
1292          *
1293          * @return String representation of this title
1294          */
1295         public function __toString() {
1296                 return $this->getPrefixedText();
1297         }
1298
1299         /**
1300          * Get the prefixed title with spaces, plus any fragment
1301          * (part beginning with '#')
1302          *
1303          * @return String the prefixed title, with spaces and the fragment, including '#'
1304          */
1305         public function getFullText() {
1306                 $text = $this->getPrefixedText();
1307                 if ( $this->hasFragment() ) {
1308                         $text .= '#' . $this->getFragment();
1309                 }
1310                 return $text;
1311         }
1312
1313         /**
1314          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1315          *
1316          * @par Example:
1317          * @code
1318          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1319          * # returns: 'Foo'
1320          * @endcode
1321          *
1322          * @return String Root name
1323          * @since 1.20
1324          */
1325         public function getRootText() {
1326                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1327                         return $this->getText();
1328                 }
1329
1330                 return strtok( $this->getText(), '/' );
1331         }
1332
1333         /**
1334          * Get the root page name title, i.e. the leftmost part before any slashes
1335          *
1336          * @par Example:
1337          * @code
1338          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1339          * # returns: Title{User:Foo}
1340          * @endcode
1341          *
1342          * @return Title Root title
1343          * @since 1.20
1344          */
1345         public function getRootTitle() {
1346                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1347         }
1348
1349         /**
1350          * Get the base page name without a namespace, i.e. the part before the subpage name
1351          *
1352          * @par Example:
1353          * @code
1354          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1355          * # returns: 'Foo/Bar'
1356          * @endcode
1357          *
1358          * @return String Base name
1359          */
1360         public function getBaseText() {
1361                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1362                         return $this->getText();
1363                 }
1364
1365                 $parts = explode( '/', $this->getText() );
1366                 # Don't discard the real title if there's no subpage involved
1367                 if ( count( $parts ) > 1 ) {
1368                         unset( $parts[count( $parts ) - 1] );
1369                 }
1370                 return implode( '/', $parts );
1371         }
1372
1373         /**
1374          * Get the base page name title, i.e. the part before the subpage name
1375          *
1376          * @par Example:
1377          * @code
1378          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1379          * # returns: Title{User:Foo/Bar}
1380          * @endcode
1381          *
1382          * @return Title Base title
1383          * @since 1.20
1384          */
1385         public function getBaseTitle() {
1386                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1387         }
1388
1389         /**
1390          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1391          *
1392          * @par Example:
1393          * @code
1394          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1395          * # returns: "Baz"
1396          * @endcode
1397          *
1398          * @return String Subpage name
1399          */
1400         public function getSubpageText() {
1401                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1402                         return $this->mTextform;
1403                 }
1404                 $parts = explode( '/', $this->mTextform );
1405                 return $parts[count( $parts ) - 1];
1406         }
1407
1408         /**
1409          * Get the title for a subpage of the current page
1410          *
1411          * @par Example:
1412          * @code
1413          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1414          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1415          * @endcode
1416          *
1417          * @param string $text The subpage name to add to the title
1418          * @return Title Subpage title
1419          * @since 1.20
1420          */
1421         public function getSubpage( $text ) {
1422                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1423         }
1424
1425         /**
1426          * Get the HTML-escaped displayable text form.
1427          * Used for the title field in <a> tags.
1428          *
1429          * @return String the text, including any prefixes
1430          * @deprecated since 1.19
1431          */
1432         public function getEscapedText() {
1433                 wfDeprecated( __METHOD__, '1.19' );
1434                 return htmlspecialchars( $this->getPrefixedText() );
1435         }
1436
1437         /**
1438          * Get a URL-encoded form of the subpage text
1439          *
1440          * @return String URL-encoded subpage name
1441          */
1442         public function getSubpageUrlForm() {
1443                 $text = $this->getSubpageText();
1444                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1445                 return $text;
1446         }
1447
1448         /**
1449          * Get a URL-encoded title (not an actual URL) including interwiki
1450          *
1451          * @return String the URL-encoded form
1452          */
1453         public function getPrefixedURL() {
1454                 $s = $this->prefix( $this->mDbkeyform );
1455                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1456                 return $s;
1457         }
1458
1459         /**
1460          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1461          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1462          * second argument named variant. This was deprecated in favor
1463          * of passing an array of option with a "variant" key
1464          * Once $query2 is removed for good, this helper can be dropped
1465          * and the wfArrayToCgi moved to getLocalURL();
1466          *
1467          * @since 1.19 (r105919)
1468          * @param $query
1469          * @param $query2 bool
1470          * @return String
1471          */
1472         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1473                 if ( $query2 !== false ) {
1474                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1475                                 "method called with a second parameter is deprecated. Add your " .
1476                                 "parameter to an array passed as the first parameter.", "1.19" );
1477                 }
1478                 if ( is_array( $query ) ) {
1479                         $query = wfArrayToCgi( $query );
1480                 }
1481                 if ( $query2 ) {
1482                         if ( is_string( $query2 ) ) {
1483                                 // $query2 is a string, we will consider this to be
1484                                 // a deprecated $variant argument and add it to the query
1485                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1486                         } else {
1487                                 $query2 = wfArrayToCgi( $query2 );
1488                         }
1489                         // If we have $query content add a & to it first
1490                         if ( $query ) {
1491                                 $query .= '&';
1492                         }
1493                         // Now append the queries together
1494                         $query .= $query2;
1495                 }
1496                 return $query;
1497         }
1498
1499         /**
1500          * Get a real URL referring to this title, with interwiki link and
1501          * fragment
1502          *
1503          * See getLocalURL for the arguments.
1504          *
1505          * @see self::getLocalURL
1506          * @see wfExpandUrl
1507          * @param $query
1508          * @param $query2 bool
1509          * @param $proto Protocol type to use in URL
1510          * @return String the URL
1511          */
1512         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1513                 $query = self::fixUrlQueryArgs( $query, $query2 );
1514
1515                 # Hand off all the decisions on urls to getLocalURL
1516                 $url = $this->getLocalURL( $query );
1517
1518                 # Expand the url to make it a full url. Note that getLocalURL has the
1519                 # potential to output full urls for a variety of reasons, so we use
1520                 # wfExpandUrl instead of simply prepending $wgServer
1521                 $url = wfExpandUrl( $url, $proto );
1522
1523                 # Finally, add the fragment.
1524                 $url .= $this->getFragmentForURL();
1525
1526                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1527                 return $url;
1528         }
1529
1530         /**
1531          * Get a URL with no fragment or server name.  If this page is generated
1532          * with action=render, $wgServer is prepended.
1533          *
1534          * @param string|array $query an optional query string,
1535          *   not used for interwiki links. Can be specified as an associative array as well,
1536          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1537          *   Some query patterns will trigger various shorturl path replacements.
1538          * @param $query2 Mixed: An optional secondary query array. This one MUST
1539          *   be an array. If a string is passed it will be interpreted as a deprecated
1540          *   variant argument and urlencoded into a variant= argument.
1541          *   This second query argument will be added to the $query
1542          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1543          *   pair in the first parameter array instead.
1544          *
1545          * @return String the URL
1546          */
1547         public function getLocalURL( $query = '', $query2 = false ) {
1548                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1549
1550                 $query = self::fixUrlQueryArgs( $query, $query2 );
1551
1552                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1553                 if ( $interwiki ) {
1554                         $namespace = $this->getNsText();
1555                         if ( $namespace != '' ) {
1556                                 # Can this actually happen? Interwikis shouldn't be parsed.
1557                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1558                                 $namespace .= ':';
1559                         }
1560                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1561                         $url = wfAppendQuery( $url, $query );
1562                 } else {
1563                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1564                         if ( $query == '' ) {
1565                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1566                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1567                         } else {
1568                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1569                                 $url = false;
1570                                 $matches = array();
1571
1572                                 if ( !empty( $wgActionPaths )
1573                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1574                                 ) {
1575                                         $action = urldecode( $matches[2] );
1576                                         if ( isset( $wgActionPaths[$action] ) ) {
1577                                                 $query = $matches[1];
1578                                                 if ( isset( $matches[4] ) ) {
1579                                                         $query .= $matches[4];
1580                                                 }
1581                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1582                                                 if ( $query != '' ) {
1583                                                         $url = wfAppendQuery( $url, $query );
1584                                                 }
1585                                         }
1586                                 }
1587
1588                                 if ( $url === false
1589                                         && $wgVariantArticlePath
1590                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1591                                         && $this->getPageLanguage()->hasVariants()
1592                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1593                                 ) {
1594                                         $variant = urldecode( $matches[1] );
1595                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1596                                                 // Only do the variant replacement if the given variant is a valid
1597                                                 // variant for the page's language.
1598                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1599                                                 $url = str_replace( '$1', $dbkey, $url );
1600                                         }
1601                                 }
1602
1603                                 if ( $url === false ) {
1604                                         if ( $query == '-' ) {
1605                                                 $query = '';
1606                                         }
1607                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1608                                 }
1609                         }
1610
1611                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1612
1613                         // @todo FIXME: This causes breakage in various places when we
1614                         // actually expected a local URL and end up with dupe prefixes.
1615                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1616                                 $url = $wgServer . $url;
1617                         }
1618                 }
1619                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1620                 return $url;
1621         }
1622
1623         /**
1624          * Get a URL that's the simplest URL that will be valid to link, locally,
1625          * to the current Title.  It includes the fragment, but does not include
1626          * the server unless action=render is used (or the link is external).  If
1627          * there's a fragment but the prefixed text is empty, we just return a link
1628          * to the fragment.
1629          *
1630          * The result obviously should not be URL-escaped, but does need to be
1631          * HTML-escaped if it's being output in HTML.
1632          *
1633          * See getLocalURL for the arguments.
1634          *
1635          * @param $query
1636          * @param $query2 bool
1637          * @param $proto Protocol to use; setting this will cause a full URL to be used
1638          * @see self::getLocalURL
1639          * @return String the URL
1640          */
1641         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1642                 wfProfileIn( __METHOD__ );
1643                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1644                         $ret = $this->getFullURL( $query, $query2, $proto );
1645                 } elseif ( $this->getPrefixedText() === '' && $this->hasFragment() ) {
1646                         $ret = $this->getFragmentForURL();
1647                 } else {
1648                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1649                 }
1650                 wfProfileOut( __METHOD__ );
1651                 return $ret;
1652         }
1653
1654         /**
1655          * Get an HTML-escaped version of the URL form, suitable for
1656          * using in a link, without a server name or fragment
1657          *
1658          * See getLocalURL for the arguments.
1659          *
1660          * @see self::getLocalURL
1661          * @param $query string
1662          * @param $query2 bool|string
1663          * @return String the URL
1664          * @deprecated since 1.19
1665          */
1666         public function escapeLocalURL( $query = '', $query2 = false ) {
1667                 wfDeprecated( __METHOD__, '1.19' );
1668                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1669         }
1670
1671         /**
1672          * Get an HTML-escaped version of the URL form, suitable for
1673          * using in a link, including the server name and fragment
1674          *
1675          * See getLocalURL for the arguments.
1676          *
1677          * @see self::getLocalURL
1678          * @return String the URL
1679          * @deprecated since 1.19
1680          */
1681         public function escapeFullURL( $query = '', $query2 = false ) {
1682                 wfDeprecated( __METHOD__, '1.19' );
1683                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1684         }
1685
1686         /**
1687          * Get the URL form for an internal link.
1688          * - Used in various Squid-related code, in case we have a different
1689          * internal hostname for the server from the exposed one.
1690          *
1691          * This uses $wgInternalServer to qualify the path, or $wgServer
1692          * if $wgInternalServer is not set. If the server variable used is
1693          * protocol-relative, the URL will be expanded to http://
1694          *
1695          * See getLocalURL for the arguments.
1696          *
1697          * @see self::getLocalURL
1698          * @return String the URL
1699          */
1700         public function getInternalURL( $query = '', $query2 = false ) {
1701                 global $wgInternalServer, $wgServer;
1702                 $query = self::fixUrlQueryArgs( $query, $query2 );
1703                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1704                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1705                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1706                 return $url;
1707         }
1708
1709         /**
1710          * Get the URL for a canonical link, for use in things like IRC and
1711          * e-mail notifications. Uses $wgCanonicalServer and the
1712          * GetCanonicalURL hook.
1713          *
1714          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1715          *
1716          * See getLocalURL for the arguments.
1717          *
1718          * @see self::getLocalURL
1719          * @return string The URL
1720          * @since 1.18
1721          */
1722         public function getCanonicalURL( $query = '', $query2 = false ) {
1723                 $query = self::fixUrlQueryArgs( $query, $query2 );
1724                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1725                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1726                 return $url;
1727         }
1728
1729         /**
1730          * HTML-escaped version of getCanonicalURL()
1731          *
1732          * See getLocalURL for the arguments.
1733          *
1734          * @see self::getLocalURL
1735          * @since 1.18
1736          * @return string
1737          * @deprecated since 1.19
1738          */
1739         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1740                 wfDeprecated( __METHOD__, '1.19' );
1741                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1742         }
1743
1744         /**
1745          * Get the edit URL for this Title
1746          *
1747          * @return String the URL, or a null string if this is an
1748          *  interwiki link
1749          */
1750         public function getEditURL() {
1751                 if ( $this->isExternal() ) {
1752                         return '';
1753                 }
1754                 $s = $this->getLocalURL( 'action=edit' );
1755
1756                 return $s;
1757         }
1758
1759         /**
1760          * Is $wgUser watching this page?
1761          *
1762          * @deprecated in 1.20; use User::isWatched() instead.
1763          * @return Bool
1764          */
1765         public function userIsWatching() {
1766                 global $wgUser;
1767
1768                 if ( is_null( $this->mWatched ) ) {
1769                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1770                                 $this->mWatched = false;
1771                         } else {
1772                                 $this->mWatched = $wgUser->isWatched( $this );
1773                         }
1774                 }
1775                 return $this->mWatched;
1776         }
1777
1778         /**
1779          * Can $wgUser read this page?
1780          *
1781          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1782          * @return Bool
1783          */
1784         public function userCanRead() {
1785                 wfDeprecated( __METHOD__, '1.19' );
1786                 return $this->userCan( 'read' );
1787         }
1788
1789         /**
1790          * Can $user perform $action on this page?
1791          * This skips potentially expensive cascading permission checks
1792          * as well as avoids expensive error formatting
1793          *
1794          * Suitable for use for nonessential UI controls in common cases, but
1795          * _not_ for functional access control.
1796          *
1797          * May provide false positives, but should never provide a false negative.
1798          *
1799          * @param string $action action that permission needs to be checked for
1800          * @param $user User to check (since 1.19); $wgUser will be used if not
1801          *              provided.
1802          * @return Bool
1803          */
1804         public function quickUserCan( $action, $user = null ) {
1805                 return $this->userCan( $action, $user, false );
1806         }
1807
1808         /**
1809          * Can $user perform $action on this page?
1810          *
1811          * @param string $action action that permission needs to be checked for
1812          * @param $user User to check (since 1.19); $wgUser will be used if not
1813          *   provided.
1814          * @param bool $doExpensiveQueries Set this to false to avoid doing
1815          *   unnecessary queries.
1816          * @return Bool
1817          */
1818         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1819                 if ( !$user instanceof User ) {
1820                         global $wgUser;
1821                         $user = $wgUser;
1822                 }
1823                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1824         }
1825
1826         /**
1827          * Can $user perform $action on this page?
1828          *
1829          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1830          *
1831          * @param string $action action that permission needs to be checked for
1832          * @param $user User to check
1833          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1834          *   queries by skipping checks for cascading protections and user blocks.
1835          * @param array $ignoreErrors of Strings Set this to a list of message keys
1836          *   whose corresponding errors may be ignored.
1837          * @return Array of arguments to wfMessage to explain permissions problems.
1838          */
1839         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1840                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1841
1842                 // Remove the errors being ignored.
1843                 foreach ( $errors as $index => $error ) {
1844                         $error_key = is_array( $error ) ? $error[0] : $error;
1845
1846                         if ( in_array( $error_key, $ignoreErrors ) ) {
1847                                 unset( $errors[$index] );
1848                         }
1849                 }
1850
1851                 return $errors;
1852         }
1853
1854         /**
1855          * Permissions checks that fail most often, and which are easiest to test.
1856          *
1857          * @param string $action the action to check
1858          * @param $user User user to check
1859          * @param array $errors list of current errors
1860          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1861          * @param $short Boolean short circuit on first error
1862          *
1863          * @return Array list of errors
1864          */
1865         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1866                 if ( !wfRunHooks( 'TitleQuickPermissions', array( $this, $user, $action, &$errors, $doExpensiveQueries, $short ) ) ) {
1867                         return $errors;
1868                 }
1869
1870                 if ( $action == 'create' ) {
1871                         if (
1872                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1873                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1874                         ) {
1875                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1876                         }
1877                 } elseif ( $action == 'move' ) {
1878                         if ( !$user->isAllowed( 'move-rootuserpages' )
1879                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1880                                 // Show user page-specific message only if the user can move other pages
1881                                 $errors[] = array( 'cant-move-user-page' );
1882                         }
1883
1884                         // Check if user is allowed to move files if it's a file
1885                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1886                                 $errors[] = array( 'movenotallowedfile' );
1887                         }
1888
1889                         if ( !$user->isAllowed( 'move' ) ) {
1890                                 // User can't move anything
1891                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1892                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1893                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1894                                         // custom message if logged-in users without any special rights can move
1895                                         $errors[] = array( 'movenologintext' );
1896                                 } else {
1897                                         $errors[] = array( 'movenotallowed' );
1898                                 }
1899                         }
1900                 } elseif ( $action == 'move-target' ) {
1901                         if ( !$user->isAllowed( 'move' ) ) {
1902                                 // User can't move anything
1903                                 $errors[] = array( 'movenotallowed' );
1904                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1905                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1906                                 // Show user page-specific message only if the user can move other pages
1907                                 $errors[] = array( 'cant-move-to-user-page' );
1908                         }
1909                 } elseif ( !$user->isAllowed( $action ) ) {
1910                         $errors[] = $this->missingPermissionError( $action, $short );
1911                 }
1912
1913                 return $errors;
1914         }
1915
1916         /**
1917          * Add the resulting error code to the errors array
1918          *
1919          * @param array $errors list of current errors
1920          * @param $result Mixed result of errors
1921          *
1922          * @return Array list of errors
1923          */
1924         private function resultToError( $errors, $result ) {
1925                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1926                         // A single array representing an error
1927                         $errors[] = $result;
1928                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1929                         // A nested array representing multiple errors
1930                         $errors = array_merge( $errors, $result );
1931                 } elseif ( $result !== '' && is_string( $result ) ) {
1932                         // A string representing a message-id
1933                         $errors[] = array( $result );
1934                 } elseif ( $result === false ) {
1935                         // a generic "We don't want them to do that"
1936                         $errors[] = array( 'badaccess-group0' );
1937                 }
1938                 return $errors;
1939         }
1940
1941         /**
1942          * Check various permission hooks
1943          *
1944          * @param string $action the action to check
1945          * @param $user User user to check
1946          * @param array $errors list of current errors
1947          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1948          * @param $short Boolean short circuit on first error
1949          *
1950          * @return Array list of errors
1951          */
1952         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1953                 // Use getUserPermissionsErrors instead
1954                 $result = '';
1955                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1956                         return $result ? array() : array( array( 'badaccess-group0' ) );
1957                 }
1958                 // Check getUserPermissionsErrors hook
1959                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1960                         $errors = $this->resultToError( $errors, $result );
1961                 }
1962                 // Check getUserPermissionsErrorsExpensive hook
1963                 if (
1964                         $doExpensiveQueries
1965                         && !( $short && count( $errors ) > 0 )
1966                         && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
1967                 ) {
1968                         $errors = $this->resultToError( $errors, $result );
1969                 }
1970
1971                 return $errors;
1972         }
1973
1974         /**
1975          * Check permissions on special pages & namespaces
1976          *
1977          * @param string $action the action to check
1978          * @param $user User user to check
1979          * @param array $errors list of current errors
1980          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1981          * @param $short Boolean short circuit on first error
1982          *
1983          * @return Array list of errors
1984          */
1985         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1986                 # Only 'createaccount' can be performed on special pages,
1987                 # which don't actually exist in the DB.
1988                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
1989                         $errors[] = array( 'ns-specialprotected' );
1990                 }
1991
1992                 # Check $wgNamespaceProtection for restricted namespaces
1993                 if ( $this->isNamespaceProtected( $user ) ) {
1994                         $ns = $this->mNamespace == NS_MAIN ?
1995                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
1996                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1997                                 array( 'protectedinterface' ) : array( 'namespaceprotected', $ns );
1998                 }
1999
2000                 return $errors;
2001         }
2002
2003         /**
2004          * Check CSS/JS sub-page permissions
2005          *
2006          * @param string $action the action to check
2007          * @param $user User user to check
2008          * @param array $errors list of current errors
2009          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2010          * @param $short Boolean short circuit on first error
2011          *
2012          * @return Array list of errors
2013          */
2014         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2015                 # Protect css/js subpages of user pages
2016                 # XXX: this might be better using restrictions
2017                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2018                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2019                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2020                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2021                                         $errors[] = array( 'mycustomcssprotected' );
2022                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2023                                         $errors[] = array( 'mycustomjsprotected' );
2024                                 }
2025                         } else {
2026                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2027                                         $errors[] = array( 'customcssprotected' );
2028                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2029                                         $errors[] = array( 'customjsprotected' );
2030                                 }
2031                         }
2032                 }
2033
2034                 return $errors;
2035         }
2036
2037         /**
2038          * Check against page_restrictions table requirements on this
2039          * page. The user must possess all required rights for this
2040          * action.
2041          *
2042          * @param string $action the action to check
2043          * @param $user User user to check
2044          * @param array $errors list of current errors
2045          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2046          * @param $short Boolean short circuit on first error
2047          *
2048          * @return Array list of errors
2049          */
2050         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2051                 foreach ( $this->getRestrictions( $action ) as $right ) {
2052                         // Backwards compatibility, rewrite sysop -> editprotected
2053                         if ( $right == 'sysop' ) {
2054                                 $right = 'editprotected';
2055                         }
2056                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2057                         if ( $right == 'autoconfirmed' ) {
2058                                 $right = 'editsemiprotected';
2059                         }
2060                         if ( $right == '' ) {
2061                                 continue;
2062                         }
2063                         if ( !$user->isAllowed( $right ) ) {
2064                                 $errors[] = array( 'protectedpagetext', $right );
2065                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2066                                 $errors[] = array( 'protectedpagetext', 'protect' );
2067                         }
2068                 }
2069
2070                 return $errors;
2071         }
2072
2073         /**
2074          * Check restrictions on cascading pages.
2075          *
2076          * @param string $action the action to check
2077          * @param $user User to check
2078          * @param array $errors list of current errors
2079          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2080          * @param $short Boolean short circuit on first error
2081          *
2082          * @return Array list of errors
2083          */
2084         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2085                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
2086                         # We /could/ use the protection level on the source page, but it's
2087                         # fairly ugly as we have to establish a precedence hierarchy for pages
2088                         # included by multiple cascade-protected pages. So just restrict
2089                         # it to people with 'protect' permission, as they could remove the
2090                         # protection anyway.
2091                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2092                         # Cascading protection depends on more than this page...
2093                         # Several cascading protected pages may include this page...
2094                         # Check each cascading level
2095                         # This is only for protection restrictions, not for all actions
2096                         if ( isset( $restrictions[$action] ) ) {
2097                                 foreach ( $restrictions[$action] as $right ) {
2098                                         // Backwards compatibility, rewrite sysop -> editprotected
2099                                         if ( $right == 'sysop' ) {
2100                                                 $right = 'editprotected';
2101                                         }
2102                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2103                                         if ( $right == 'autoconfirmed' ) {
2104                                                 $right = 'editsemiprotected';
2105                                         }
2106                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2107                                                 $pages = '';
2108                                                 foreach ( $cascadingSources as $page ) {
2109                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2110                                                 }
2111                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
2112                                         }
2113                                 }
2114                         }
2115                 }
2116
2117                 return $errors;
2118         }
2119
2120         /**
2121          * Check action permissions not already checked in checkQuickPermissions
2122          *
2123          * @param string $action the action to check
2124          * @param $user User to check
2125          * @param array $errors list of current errors
2126          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2127          * @param $short Boolean short circuit on first error
2128          *
2129          * @return Array list of errors
2130          */
2131         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2132                 global $wgDeleteRevisionsLimit, $wgLang;
2133
2134                 if ( $action == 'protect' ) {
2135                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
2136                                 // If they can't edit, they shouldn't protect.
2137                                 $errors[] = array( 'protect-cantedit' );
2138                         }
2139                 } elseif ( $action == 'create' ) {
2140                         $title_protection = $this->getTitleProtection();
2141                         if ( $title_protection ) {
2142                                 if ( $title_protection['pt_create_perm'] == 'sysop' ) {
2143                                         $title_protection['pt_create_perm'] = 'editprotected'; // B/C
2144                                 }
2145                                 if ( $title_protection['pt_create_perm'] == 'autoconfirmed' ) {
2146                                         $title_protection['pt_create_perm'] = 'editsemiprotected'; // B/C
2147                                 }
2148                                 if ( $title_protection['pt_create_perm'] == ''
2149                                         || !$user->isAllowed( $title_protection['pt_create_perm'] )
2150                                 ) {
2151                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
2152                                 }
2153                         }
2154                 } elseif ( $action == 'move' ) {
2155                         // Check for immobile pages
2156                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2157                                 // Specific message for this case
2158                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2159                         } elseif ( !$this->isMovable() ) {
2160                                 // Less specific message for rarer cases
2161                                 $errors[] = array( 'immobile-source-page' );
2162                         }
2163                 } elseif ( $action == 'move-target' ) {
2164                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2165                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2166                         } elseif ( !$this->isMovable() ) {
2167                                 $errors[] = array( 'immobile-target-page' );
2168                         }
2169                 } elseif ( $action == 'delete' ) {
2170                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2171                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2172                         ) {
2173                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2174                         }
2175                 }
2176                 return $errors;
2177         }
2178
2179         /**
2180          * Check that the user isn't blocked from editing.
2181          *
2182          * @param string $action the action to check
2183          * @param $user User to check
2184          * @param array $errors list of current errors
2185          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2186          * @param $short Boolean short circuit on first error
2187          *
2188          * @return Array list of errors
2189          */
2190         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2191                 // Account creation blocks handled at userlogin.
2192                 // Unblocking handled in SpecialUnblock
2193                 if ( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2194                         return $errors;
2195                 }
2196
2197                 global $wgEmailConfirmToEdit;
2198
2199                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2200                         $errors[] = array( 'confirmedittext' );
2201                 }
2202
2203                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2204                         // Don't block the user from editing their own talk page unless they've been
2205                         // explicitly blocked from that too.
2206                 } elseif ( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2207                         // @todo FIXME: Pass the relevant context into this function.
2208                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2209                 }
2210
2211                 return $errors;
2212         }
2213
2214         /**
2215          * Check that the user is allowed to read this page.
2216          *
2217          * @param string $action the action to check
2218          * @param $user User to check
2219          * @param array $errors list of current errors
2220          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2221          * @param $short Boolean short circuit on first error
2222          *
2223          * @return Array list of errors
2224          */
2225         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2226                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2227
2228                 $whitelisted = false;
2229                 if ( User::isEveryoneAllowed( 'read' ) ) {
2230                         # Shortcut for public wikis, allows skipping quite a bit of code
2231                         $whitelisted = true;
2232                 } elseif ( $user->isAllowed( 'read' ) ) {
2233                         # If the user is allowed to read pages, he is allowed to read all pages
2234                         $whitelisted = true;
2235                 } elseif ( $this->isSpecial( 'Userlogin' )
2236                         || $this->isSpecial( 'ChangePassword' )
2237                         || $this->isSpecial( 'PasswordReset' )
2238                 ) {
2239                         # Always grant access to the login page.
2240                         # Even anons need to be able to log in.
2241                         $whitelisted = true;
2242                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2243                         # Time to check the whitelist
2244                         # Only do these checks is there's something to check against
2245                         $name = $this->getPrefixedText();
2246                         $dbName = $this->getPrefixedDBkey();
2247
2248                         // Check for explicit whitelisting with and without underscores
2249                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2250                                 $whitelisted = true;
2251                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2252                                 # Old settings might have the title prefixed with
2253                                 # a colon for main-namespace pages
2254                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2255                                         $whitelisted = true;
2256                                 }
2257                         } elseif ( $this->isSpecialPage() ) {
2258                                 # If it's a special page, ditch the subpage bit and check again
2259                                 $name = $this->getDBkey();
2260                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2261                                 if ( $name ) {
2262                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2263                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2264                                                 $whitelisted = true;
2265                                         }
2266                                 }
2267                         }
2268                 }
2269
2270                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2271                         $name = $this->getPrefixedText();
2272                         // Check for regex whitelisting
2273                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2274                                 if ( preg_match( $listItem, $name ) ) {
2275                                         $whitelisted = true;
2276                                         break;
2277                                 }
2278                         }
2279                 }
2280
2281                 if ( !$whitelisted ) {
2282                         # If the title is not whitelisted, give extensions a chance to do so...
2283                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2284                         if ( !$whitelisted ) {
2285                                 $errors[] = $this->missingPermissionError( $action, $short );
2286                         }
2287                 }
2288
2289                 return $errors;
2290         }
2291
2292         /**
2293          * Get a description array when the user doesn't have the right to perform
2294          * $action (i.e. when User::isAllowed() returns false)
2295          *
2296          * @param string $action the action to check
2297          * @param $short Boolean short circuit on first error
2298          * @return Array list of errors
2299          */
2300         private function missingPermissionError( $action, $short ) {
2301                 // We avoid expensive display logic for quickUserCan's and such
2302                 if ( $short ) {
2303                         return array( 'badaccess-group0' );
2304                 }
2305
2306                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2307                         User::getGroupsWithPermission( $action ) );
2308
2309                 if ( count( $groups ) ) {
2310                         global $wgLang;
2311                         return array(
2312                                 'badaccess-groups',
2313                                 $wgLang->commaList( $groups ),
2314                                 count( $groups )
2315                         );
2316                 } else {
2317                         return array( 'badaccess-group0' );
2318                 }
2319         }
2320
2321         /**
2322          * Can $user perform $action on this page? This is an internal function,
2323          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2324          * checks on wfReadOnly() and blocks)
2325          *
2326          * @param string $action action that permission needs to be checked for
2327          * @param $user User to check
2328          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
2329          * @param bool $short Set this to true to stop after the first permission error.
2330          * @return Array of arrays of the arguments to wfMessage to explain permissions problems.
2331          */
2332         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2333                 wfProfileIn( __METHOD__ );
2334
2335                 # Read has special handling
2336                 if ( $action == 'read' ) {
2337                         $checks = array(
2338                                 'checkPermissionHooks',
2339                                 'checkReadPermissions',
2340                         );
2341                 } else {
2342                         $checks = array(
2343                                 'checkQuickPermissions',
2344                                 'checkPermissionHooks',
2345                                 'checkSpecialsAndNSPermissions',
2346                                 'checkCSSandJSPermissions',
2347                                 'checkPageRestrictions',
2348                                 'checkCascadingSourcesRestrictions',
2349                                 'checkActionPermissions',
2350                                 'checkUserBlock'
2351                         );
2352                 }
2353
2354                 $errors = array();
2355                 while ( count( $checks ) > 0 &&
2356                                 !( $short && count( $errors ) > 0 ) ) {
2357                         $method = array_shift( $checks );
2358                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2359                 }
2360
2361                 wfProfileOut( __METHOD__ );
2362                 return $errors;
2363         }
2364
2365         /**
2366          * Get a filtered list of all restriction types supported by this wiki.
2367          * @param bool $exists True to get all restriction types that apply to
2368          * titles that do exist, False for all restriction types that apply to
2369          * titles that do not exist
2370          * @return array
2371          */
2372         public static function getFilteredRestrictionTypes( $exists = true ) {
2373                 global $wgRestrictionTypes;
2374                 $types = $wgRestrictionTypes;
2375                 if ( $exists ) {
2376                         # Remove the create restriction for existing titles
2377                         $types = array_diff( $types, array( 'create' ) );
2378                 } else {
2379                         # Only the create and upload restrictions apply to non-existing titles
2380                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2381                 }
2382                 return $types;
2383         }
2384
2385         /**
2386          * Returns restriction types for the current Title
2387          *
2388          * @return array applicable restriction types
2389          */
2390         public function getRestrictionTypes() {
2391                 if ( $this->isSpecialPage() ) {
2392                         return array();
2393                 }
2394
2395                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2396
2397                 if ( $this->getNamespace() != NS_FILE ) {
2398                         # Remove the upload restriction for non-file titles
2399                         $types = array_diff( $types, array( 'upload' ) );
2400                 }
2401
2402                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2403
2404                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2405                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2406
2407                 return $types;
2408         }
2409
2410         /**
2411          * Is this title subject to title protection?
2412          * Title protection is the one applied against creation of such title.
2413          *
2414          * @return Mixed An associative array representing any existent title
2415          *   protection, or false if there's none.
2416          */
2417         private function getTitleProtection() {
2418                 // Can't protect pages in special namespaces
2419                 if ( $this->getNamespace() < 0 ) {
2420                         return false;
2421                 }
2422
2423                 // Can't protect pages that exist.
2424                 if ( $this->exists() ) {
2425                         return false;
2426                 }
2427
2428                 if ( !isset( $this->mTitleProtection ) ) {
2429                         $dbr = wfGetDB( DB_SLAVE );
2430                         $res = $dbr->select(
2431                                 'protected_titles',
2432                                 array( 'pt_user', 'pt_reason', 'pt_expiry', 'pt_create_perm' ),
2433                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2434                                 __METHOD__
2435                         );
2436
2437                         // fetchRow returns false if there are no rows.
2438                         $this->mTitleProtection = $dbr->fetchRow( $res );
2439                 }
2440                 return $this->mTitleProtection;
2441         }
2442
2443         /**
2444          * Update the title protection status
2445          *
2446          * @deprecated in 1.19; use WikiPage::doUpdateRestrictions() instead.
2447          * @param $create_perm String Permission required for creation
2448          * @param string $reason Reason for protection
2449          * @param string $expiry Expiry timestamp
2450          * @return boolean true
2451          */
2452         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2453                 wfDeprecated( __METHOD__, '1.19' );
2454
2455                 global $wgUser;
2456
2457                 $limit = array( 'create' => $create_perm );
2458                 $expiry = array( 'create' => $expiry );
2459
2460                 $page = WikiPage::factory( $this );
2461                 $cascade = false;
2462                 $status = $page->doUpdateRestrictions( $limit, $expiry, $cascade, $reason, $wgUser );
2463
2464                 return $status->isOK();
2465         }
2466
2467         /**
2468          * Remove any title protection due to page existing
2469          */
2470         public function deleteTitleProtection() {
2471                 $dbw = wfGetDB( DB_MASTER );
2472
2473                 $dbw->delete(
2474                         'protected_titles',
2475                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2476                         __METHOD__
2477                 );
2478                 $this->mTitleProtection = false;
2479         }
2480
2481         /**
2482          * Is this page "semi-protected" - the *only* protection levels are listed
2483          * in $wgSemiprotectedRestrictionLevels?
2484          *
2485          * @param string $action Action to check (default: edit)
2486          * @return Bool
2487          */
2488         public function isSemiProtected( $action = 'edit' ) {
2489                 global $wgSemiprotectedRestrictionLevels;
2490
2491                 $restrictions = $this->getRestrictions( $action );
2492                 $semi = $wgSemiprotectedRestrictionLevels;
2493                 if ( !$restrictions || !$semi ) {
2494                         // Not protected, or all protection is full protection
2495                         return false;
2496                 }
2497
2498                 // Remap autoconfirmed to editsemiprotected for BC
2499                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2500                         $semi[$key] = 'editsemiprotected';
2501                 }
2502                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2503                         $restrictions[$key] = 'editsemiprotected';
2504                 }
2505
2506                 return !array_diff( $restrictions, $semi );
2507         }
2508
2509         /**
2510          * Does the title correspond to a protected article?
2511          *
2512          * @param string $action the action the page is protected from,
2513          * by default checks all actions.
2514          * @return Bool
2515          */
2516         public function isProtected( $action = '' ) {
2517                 global $wgRestrictionLevels;
2518
2519                 $restrictionTypes = $this->getRestrictionTypes();
2520
2521                 # Special pages have inherent protection
2522                 if ( $this->isSpecialPage() ) {
2523                         return true;
2524                 }
2525
2526                 # Check regular protection levels
2527                 foreach ( $restrictionTypes as $type ) {
2528                         if ( $action == $type || $action == '' ) {
2529                                 $r = $this->getRestrictions( $type );
2530                                 foreach ( $wgRestrictionLevels as $level ) {
2531                                         if ( in_array( $level, $r ) && $level != '' ) {
2532                                                 return true;
2533                                         }
2534                                 }
2535                         }
2536                 }
2537
2538                 return false;
2539         }
2540
2541         /**
2542          * Determines if $user is unable to edit this page because it has been protected
2543          * by $wgNamespaceProtection.
2544          *
2545          * @param $user User object to check permissions
2546          * @return Bool
2547          */
2548         public function isNamespaceProtected( User $user ) {
2549                 global $wgNamespaceProtection;
2550
2551                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2552                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2553                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2554                                         return true;
2555                                 }
2556                         }
2557                 }
2558                 return false;
2559         }
2560
2561         /**
2562          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2563          *
2564          * @return Bool If the page is subject to cascading restrictions.
2565          */
2566         public function isCascadeProtected() {
2567                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2568                 return ( $sources > 0 );
2569         }
2570
2571         /**
2572          * Determines whether cascading protection sources have already been loaded from
2573          * the database.
2574          *
2575          * @param bool $getPages True to check if the pages are loaded, or false to check
2576          * if the status is loaded.
2577          * @return bool Whether or not the specified information has been loaded
2578          * @since 1.23
2579          */
2580         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2581                 return $getPages ? isset( $this->mCascadeSources ) : isset( $this->mHasCascadingRestrictions );
2582         }
2583
2584         /**
2585          * Cascading protection: Get the source of any cascading restrictions on this page.
2586          *
2587          * @param bool $getPages Whether or not to retrieve the actual pages
2588          *        that the restrictions have come from.
2589          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2590          *     have come, false for none, or true if such restrictions exist, but $getPages
2591          *     was not set.  The restriction array is an array of each type, each of which
2592          *     contains a array of unique groups.
2593          */
2594         public function getCascadeProtectionSources( $getPages = true ) {
2595                 global $wgContLang;
2596                 $pagerestrictions = array();
2597
2598                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2599                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2600                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2601                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2602                 }
2603
2604                 wfProfileIn( __METHOD__ );
2605
2606                 $dbr = wfGetDB( DB_SLAVE );
2607
2608                 if ( $this->getNamespace() == NS_FILE ) {
2609                         $tables = array( 'imagelinks', 'page_restrictions' );
2610                         $where_clauses = array(
2611                                 'il_to' => $this->getDBkey(),
2612                                 'il_from=pr_page',
2613                                 'pr_cascade' => 1
2614                         );
2615                 } else {
2616                         $tables = array( 'templatelinks', 'page_restrictions' );
2617                         $where_clauses = array(
2618                                 'tl_namespace' => $this->getNamespace(),
2619                                 'tl_title' => $this->getDBkey(),
2620                                 'tl_from=pr_page',
2621                                 'pr_cascade' => 1
2622                         );
2623                 }
2624
2625                 if ( $getPages ) {
2626                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2627                                 'pr_expiry', 'pr_type', 'pr_level' );
2628                         $where_clauses[] = 'page_id=pr_page';
2629                         $tables[] = 'page';
2630                 } else {
2631                         $cols = array( 'pr_expiry' );
2632                 }
2633
2634                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2635
2636                 $sources = $getPages ? array() : false;
2637                 $now = wfTimestampNow();
2638                 $purgeExpired = false;
2639
2640                 foreach ( $res as $row ) {
2641                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2642                         if ( $expiry > $now ) {
2643                                 if ( $getPages ) {
2644                                         $page_id = $row->pr_page;
2645                                         $page_ns = $row->page_namespace;
2646                                         $page_title = $row->page_title;
2647                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2648                                         # Add groups needed for each restriction type if its not already there
2649                                         # Make sure this restriction type still exists
2650
2651                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2652                                                 $pagerestrictions[$row->pr_type] = array();
2653                                         }
2654
2655                                         if (
2656                                                 isset( $pagerestrictions[$row->pr_type] )
2657                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2658                                         ) {
2659                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2660                                         }
2661                                 } else {
2662                                         $sources = true;
2663                                 }
2664                         } else {
2665                                 // Trigger lazy purge of expired restrictions from the db
2666                                 $purgeExpired = true;
2667                         }
2668                 }
2669                 if ( $purgeExpired ) {
2670                         Title::purgeExpiredRestrictions();
2671                 }
2672
2673                 if ( $getPages ) {
2674                         $this->mCascadeSources = $sources;
2675                         $this->mCascadingRestrictions = $pagerestrictions;
2676                 } else {
2677                         $this->mHasCascadingRestrictions = $sources;
2678                 }
2679
2680                 wfProfileOut( __METHOD__ );
2681                 return array( $sources, $pagerestrictions );
2682         }
2683
2684         /**
2685          * Accessor for mRestrictionsLoaded
2686          *
2687          * @return bool Whether or not the page's restrictions have already been
2688          * loaded from the database
2689          * @since 1.23
2690          */
2691         public function areRestrictionsLoaded() {
2692                 return $this->mRestrictionsLoaded;
2693         }
2694
2695         /**
2696          * Accessor/initialisation for mRestrictions
2697          *
2698          * @param string $action action that permission needs to be checked for
2699          * @return Array of Strings the array of groups allowed to edit this article
2700          */
2701         public function getRestrictions( $action ) {
2702                 if ( !$this->mRestrictionsLoaded ) {
2703                         $this->loadRestrictions();
2704                 }
2705                 return isset( $this->mRestrictions[$action] )
2706                                 ? $this->mRestrictions[$action]
2707                                 : array();
2708         }
2709
2710         /**
2711          * Accessor/initialisation for mRestrictions
2712          *
2713          * @return Array of Arrays of Strings the first level indexed by
2714          * action, the second level containing the names of the groups
2715          * allowed to perform each action
2716          * @since 1.23
2717          */
2718         public function getAllRestrictions() {
2719                 if ( !$this->mRestrictionsLoaded ) {
2720                         $this->loadRestrictions();
2721                 }
2722                 return $this->mRestrictions;
2723         }
2724
2725         /**
2726          * Get the expiry time for the restriction against a given action
2727          *
2728          * @param $action
2729          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2730          *     or not protected at all, or false if the action is not recognised.
2731          */
2732         public function getRestrictionExpiry( $action ) {
2733                 if ( !$this->mRestrictionsLoaded ) {
2734                         $this->loadRestrictions();
2735                 }
2736                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2737         }
2738
2739         /**
2740          * Returns cascading restrictions for the current article
2741          *
2742          * @return Boolean
2743          */
2744         function areRestrictionsCascading() {
2745                 if ( !$this->mRestrictionsLoaded ) {
2746                         $this->loadRestrictions();
2747                 }
2748
2749                 return $this->mCascadeRestriction;
2750         }
2751
2752         /**
2753          * Loads a string into mRestrictions array
2754          *
2755          * @param $res Resource restrictions as an SQL result.
2756          * @param string $oldFashionedRestrictions comma-separated list of page
2757          *        restrictions from page table (pre 1.10)
2758          */
2759         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2760                 $rows = array();
2761
2762                 foreach ( $res as $row ) {
2763                         $rows[] = $row;
2764                 }
2765
2766                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2767         }
2768
2769         /**
2770          * Compiles list of active page restrictions from both page table (pre 1.10)
2771          * and page_restrictions table for this existing page.
2772          * Public for usage by LiquidThreads.
2773          *
2774          * @param array $rows of db result objects
2775          * @param string $oldFashionedRestrictions comma-separated list of page
2776          *        restrictions from page table (pre 1.10)
2777          */
2778         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2779                 global $wgContLang;
2780                 $dbr = wfGetDB( DB_SLAVE );
2781
2782                 $restrictionTypes = $this->getRestrictionTypes();
2783
2784                 foreach ( $restrictionTypes as $type ) {
2785                         $this->mRestrictions[$type] = array();
2786                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2787                 }
2788
2789                 $this->mCascadeRestriction = false;
2790
2791                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2792
2793                 if ( $oldFashionedRestrictions === null ) {
2794                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2795                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2796                 }
2797
2798                 if ( $oldFashionedRestrictions != '' ) {
2799
2800                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2801                                 $temp = explode( '=', trim( $restrict ) );
2802                                 if ( count( $temp ) == 1 ) {
2803                                         // old old format should be treated as edit/move restriction
2804                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2805                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2806                                 } else {
2807                                         $restriction = trim( $temp[1] );
2808                                         if ( $restriction != '' ) { //some old entries are empty
2809                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2810                                         }
2811                                 }
2812                         }
2813
2814                         $this->mOldRestrictions = true;
2815
2816                 }
2817
2818                 if ( count( $rows ) ) {
2819                         # Current system - load second to make them override.
2820                         $now = wfTimestampNow();
2821                         $purgeExpired = false;
2822
2823                         # Cycle through all the restrictions.
2824                         foreach ( $rows as $row ) {
2825
2826                                 // Don't take care of restrictions types that aren't allowed
2827                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2828                                         continue;
2829                                 }
2830
2831                                 // This code should be refactored, now that it's being used more generally,
2832                                 // But I don't really see any harm in leaving it in Block for now -werdna
2833                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2834
2835                                 // Only apply the restrictions if they haven't expired!
2836                                 if ( !$expiry || $expiry > $now ) {
2837                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2838                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2839
2840                                         $this->mCascadeRestriction |= $row->pr_cascade;
2841                                 } else {
2842                                         // Trigger a lazy purge of expired restrictions
2843                                         $purgeExpired = true;
2844                                 }
2845                         }
2846
2847                         if ( $purgeExpired ) {
2848                                 Title::purgeExpiredRestrictions();
2849                         }
2850                 }
2851
2852                 $this->mRestrictionsLoaded = true;
2853         }
2854
2855         /**
2856          * Load restrictions from the page_restrictions table
2857          *
2858          * @param string $oldFashionedRestrictions comma-separated list of page
2859          *        restrictions from page table (pre 1.10)
2860          */
2861         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2862                 global $wgContLang;
2863                 if ( !$this->mRestrictionsLoaded ) {
2864                         if ( $this->exists() ) {
2865                                 $dbr = wfGetDB( DB_SLAVE );
2866
2867                                 $res = $dbr->select(
2868                                         'page_restrictions',
2869                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2870                                         array( 'pr_page' => $this->getArticleID() ),
2871                                         __METHOD__
2872                                 );
2873
2874                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2875                         } else {
2876                                 $title_protection = $this->getTitleProtection();
2877
2878                                 if ( $title_protection ) {
2879                                         $now = wfTimestampNow();
2880                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2881
2882                                         if ( !$expiry || $expiry > $now ) {
2883                                                 // Apply the restrictions
2884                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2885                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2886                                         } else { // Get rid of the old restrictions
2887                                                 Title::purgeExpiredRestrictions();
2888                                                 $this->mTitleProtection = false;
2889                                         }
2890                                 } else {
2891                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2892                                 }
2893                                 $this->mRestrictionsLoaded = true;
2894                         }
2895                 }
2896         }
2897
2898         /**
2899          * Flush the protection cache in this object and force reload from the database.
2900          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2901          */
2902         public function flushRestrictions() {
2903                 $this->mRestrictionsLoaded = false;
2904                 $this->mTitleProtection = null;
2905         }
2906
2907         /**
2908          * Purge expired restrictions from the page_restrictions table
2909          */
2910         static function purgeExpiredRestrictions() {
2911                 if ( wfReadOnly() ) {
2912                         return;
2913                 }
2914
2915                 $method = __METHOD__;
2916                 $dbw = wfGetDB( DB_MASTER );
2917                 $dbw->onTransactionIdle( function() use ( $dbw, $method ) {
2918                         $dbw->delete(
2919                                 'page_restrictions',
2920                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2921                                 $method
2922                         );
2923                         $dbw->delete(
2924                                 'protected_titles',
2925                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2926                                 $method
2927                         );
2928                 } );
2929         }
2930
2931         /**
2932          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2933          *
2934          * @return Bool
2935          */
2936         public function hasSubpages() {
2937                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2938                         # Duh
2939                         return false;
2940                 }
2941
2942                 # We dynamically add a member variable for the purpose of this method
2943                 # alone to cache the result.  There's no point in having it hanging
2944                 # around uninitialized in every Title object; therefore we only add it
2945                 # if needed and don't declare it statically.
2946                 if ( !isset( $this->mHasSubpages ) ) {
2947                         $this->mHasSubpages = false;
2948                         $subpages = $this->getSubpages( 1 );
2949                         if ( $subpages instanceof TitleArray ) {
2950                                 $this->mHasSubpages = (bool)$subpages->count();
2951                         }
2952                 }
2953
2954                 return $this->mHasSubpages;
2955         }
2956
2957         /**
2958          * Get all subpages of this page.
2959          *
2960          * @param int $limit maximum number of subpages to fetch; -1 for no limit
2961          * @return mixed TitleArray, or empty array if this page's namespace
2962          *  doesn't allow subpages
2963          */
2964         public function getSubpages( $limit = -1 ) {
2965                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2966                         return array();
2967                 }
2968
2969                 $dbr = wfGetDB( DB_SLAVE );
2970                 $conds['page_namespace'] = $this->getNamespace();
2971                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2972                 $options = array();
2973                 if ( $limit > -1 ) {
2974                         $options['LIMIT'] = $limit;
2975                 }
2976                 $this->mSubpages = TitleArray::newFromResult(
2977                         $dbr->select( 'page',
2978                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2979                                 $conds,
2980                                 __METHOD__,
2981                                 $options
2982                         )
2983                 );
2984                 return $this->mSubpages;
2985         }
2986
2987         /**
2988          * Is there a version of this page in the deletion archive?
2989          *
2990          * @return Int the number of archived revisions
2991          */
2992         public function isDeleted() {
2993                 if ( $this->getNamespace() < 0 ) {
2994                         $n = 0;
2995                 } else {
2996                         $dbr = wfGetDB( DB_SLAVE );
2997
2998                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2999                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3000                                 __METHOD__
3001                         );
3002                         if ( $this->getNamespace() == NS_FILE ) {
3003                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
3004                                         array( 'fa_name' => $this->getDBkey() ),
3005                                         __METHOD__
3006                                 );
3007                         }
3008                 }
3009                 return (int)$n;
3010         }
3011
3012         /**
3013          * Is there a version of this page in the deletion archive?
3014          *
3015          * @return Boolean
3016          */
3017         public function isDeletedQuick() {
3018                 if ( $this->getNamespace() < 0 ) {
3019                         return false;
3020                 }
3021                 $dbr = wfGetDB( DB_SLAVE );
3022                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3023                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3024                         __METHOD__
3025                 );
3026                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3027                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3028                                 array( 'fa_name' => $this->getDBkey() ),
3029                                 __METHOD__
3030                         );
3031                 }
3032                 return $deleted;
3033         }
3034
3035         /**
3036          * Get the article ID for this Title from the link cache,
3037          * adding it if necessary
3038          *
3039          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select
3040          *  for update
3041          * @return Int the ID
3042          */
3043         public function getArticleID( $flags = 0 ) {
3044                 if ( $this->getNamespace() < 0 ) {
3045                         $this->mArticleID = 0;
3046                         return $this->mArticleID;
3047                 }
3048                 $linkCache = LinkCache::singleton();
3049                 if ( $flags & self::GAID_FOR_UPDATE ) {
3050                         $oldUpdate = $linkCache->forUpdate( true );
3051                         $linkCache->clearLink( $this );
3052                         $this->mArticleID = $linkCache->addLinkObj( $this );
3053                         $linkCache->forUpdate( $oldUpdate );
3054                 } else {
3055                         if ( -1 == $this->mArticleID ) {
3056                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3057                         }
3058                 }
3059                 return $this->mArticleID;
3060         }
3061
3062         /**
3063          * Is this an article that is a redirect page?
3064          * Uses link cache, adding it if necessary
3065          *
3066          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3067          * @return Bool
3068          */
3069         public function isRedirect( $flags = 0 ) {
3070                 if ( !is_null( $this->mRedirect ) ) {
3071                         return $this->mRedirect;
3072                 }
3073                 # Calling getArticleID() loads the field from cache as needed
3074                 if ( !$this->getArticleID( $flags ) ) {
3075                         $this->mRedirect = false;
3076                         return $this->mRedirect;
3077                 }
3078
3079                 $linkCache = LinkCache::singleton();
3080                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3081                 if ( $cached === null ) {
3082                         # Trust LinkCache's state over our own
3083                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3084                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3085                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3086                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3087                         # LinkCache to refresh its data from the master.
3088                         $this->mRedirect = false;
3089                         return $this->mRedirect;
3090                 }
3091
3092                 $this->mRedirect = (bool)$cached;
3093
3094                 return $this->mRedirect;
3095         }
3096
3097         /**
3098          * What is the length of this page?
3099          * Uses link cache, adding it if necessary
3100          *
3101          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3102          * @return Int
3103          */
3104         public function getLength( $flags = 0 ) {
3105                 if ( $this->mLength != -1 ) {
3106                         return $this->mLength;
3107                 }
3108                 # Calling getArticleID() loads the field from cache as needed
3109                 if ( !$this->getArticleID( $flags ) ) {
3110                         $this->mLength = 0;
3111                         return $this->mLength;
3112                 }
3113                 $linkCache = LinkCache::singleton();
3114                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3115                 if ( $cached === null ) {
3116                         # Trust LinkCache's state over our own, as for isRedirect()
3117                         $this->mLength = 0;
3118                         return $this->mLength;
3119                 }
3120
3121                 $this->mLength = intval( $cached );
3122
3123                 return $this->mLength;
3124         }
3125
3126         /**
3127          * What is the page_latest field for this page?
3128          *
3129          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3130          * @return Int or 0 if the page doesn't exist
3131          */
3132         public function getLatestRevID( $flags = 0 ) {
3133                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3134                         return intval( $this->mLatestID );
3135                 }
3136                 # Calling getArticleID() loads the field from cache as needed
3137                 if ( !$this->getArticleID( $flags ) ) {
3138                         $this->mLatestID = 0;
3139                         return $this->mLatestID;
3140                 }
3141                 $linkCache = LinkCache::singleton();
3142                 $linkCache->addLinkObj( $this );
3143                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3144                 if ( $cached === null ) {
3145                         # Trust LinkCache's state over our own, as for isRedirect()
3146                         $this->mLatestID = 0;
3147                         return $this->mLatestID;
3148                 }
3149
3150                 $this->mLatestID = intval( $cached );
3151
3152                 return $this->mLatestID;
3153         }
3154
3155         /**
3156          * This clears some fields in this object, and clears any associated
3157          * keys in the "bad links" section of the link cache.
3158          *
3159          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3160          * loading of the new page_id. It's also called from
3161          * WikiPage::doDeleteArticleReal()
3162          *
3163          * @param int $newid the new Article ID
3164          */
3165         public function resetArticleID( $newid ) {
3166                 $linkCache = LinkCache::singleton();
3167                 $linkCache->clearLink( $this );
3168
3169                 if ( $newid === false ) {
3170                         $this->mArticleID = -1;
3171                 } else {
3172                         $this->mArticleID = intval( $newid );
3173                 }
3174                 $this->mRestrictionsLoaded = false;
3175                 $this->mRestrictions = array();
3176                 $this->mRedirect = null;
3177                 $this->mLength = -1;
3178                 $this->mLatestID = false;
3179                 $this->mContentModel = false;
3180                 $this->mEstimateRevisions = null;
3181                 $this->mPageLanguage = false;
3182         }
3183
3184         /**
3185          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3186          *
3187          * @param string $text containing title to capitalize
3188          * @param int $ns namespace index, defaults to NS_MAIN
3189          * @return String containing capitalized title
3190          */
3191         public static function capitalize( $text, $ns = NS_MAIN ) {
3192                 global $wgContLang;
3193
3194                 if ( MWNamespace::isCapitalized( $ns ) ) {
3195                         return $wgContLang->ucfirst( $text );
3196                 } else {
3197                         return $text;
3198                 }
3199         }
3200
3201         /**
3202          * Secure and split - main initialisation function for this object
3203          *
3204          * Assumes that mDbkeyform has been set, and is urldecoded
3205          * and uses underscores, but not otherwise munged.  This function
3206          * removes illegal characters, splits off the interwiki and
3207          * namespace prefixes, sets the other forms, and canonicalizes
3208          * everything.
3209          *
3210          * @return Bool true on success
3211          */
3212         private function secureAndSplit() {
3213                 global $wgContLang, $wgLocalInterwiki;
3214
3215                 # Initialisation
3216                 $this->mInterwiki = '';
3217                 $this->mFragment = '';
3218                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3219
3220                 $dbkey = $this->mDbkeyform;
3221
3222                 # Strip Unicode bidi override characters.
3223                 # Sometimes they slip into cut-n-pasted page titles, where the
3224                 # override chars get included in list displays.
3225                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
3226
3227                 # Clean up whitespace
3228                 # Note: use of the /u option on preg_replace here will cause
3229                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
3230                 # conveniently disabling them.
3231                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
3232                 $dbkey = trim( $dbkey, '_' );
3233
3234                 if ( strpos( $dbkey, UTF8_REPLACEMENT ) !== false ) {
3235                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
3236                         return false;
3237                 }
3238
3239                 $this->mDbkeyform = $dbkey;
3240
3241                 # Initial colon indicates main namespace rather than specified default
3242                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
3243                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3244                         $this->mNamespace = NS_MAIN;
3245                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
3246                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
3247                 }
3248
3249                 if ( $dbkey == '' ) {
3250                         return false;
3251                 }
3252
3253                 # Namespace or interwiki prefix
3254                 $firstPass = true;
3255                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
3256                 do {
3257                         $m = array();
3258                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3259                                 $p = $m[1];
3260                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3261                                         # Ordinary namespace
3262                                         $dbkey = $m[2];
3263                                         $this->mNamespace = $ns;
3264                                         # For Talk:X pages, check if X has a "namespace" prefix
3265                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3266                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3267                                                         # Disallow Talk:File:x type titles...
3268                                                         return false;
3269                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3270                                                         # Disallow Talk:Interwiki:x type titles...
3271                                                         return false;
3272                                                 }
3273                                         }
3274                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3275                                         if ( !$firstPass ) {
3276                                                 # Can't make a local interwiki link to an interwiki link.
3277                                                 # That's just crazy!
3278                                                 return false;
3279                                         }
3280
3281                                         # Interwiki link
3282                                         $dbkey = $m[2];
3283                                         $this->mInterwiki = $wgContLang->lc( $p );
3284
3285                                         # Redundant interwiki prefix to the local wiki
3286                                         if ( $wgLocalInterwiki !== false
3287                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki )
3288                                         ) {
3289                                                 if ( $dbkey == '' ) {
3290                                                         # Can't have an empty self-link
3291                                                         return false;
3292                                                 }
3293                                                 $this->mInterwiki = '';
3294                                                 $firstPass = false;
3295                                                 # Do another namespace split...
3296                                                 continue;
3297                                         }
3298
3299                                         # If there's an initial colon after the interwiki, that also
3300                                         # resets the default namespace
3301                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3302                                                 $this->mNamespace = NS_MAIN;
3303                                                 $dbkey = substr( $dbkey, 1 );
3304                                         }
3305                                 }
3306                                 # If there's no recognized interwiki or namespace,
3307                                 # then let the colon expression be part of the title.
3308                         }
3309                         break;
3310                 } while ( true );
3311
3312                 $fragment = strstr( $dbkey, '#' );
3313                 if ( false !== $fragment ) {
3314                         $this->setFragment( $fragment );
3315                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3316                         # remove whitespace again: prevents "Foo_bar_#"
3317                         # becoming "Foo_bar_"
3318                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3319                 }
3320
3321                 # Reject illegal characters.
3322                 $rxTc = self::getTitleInvalidRegex();
3323                 if ( preg_match( $rxTc, $dbkey ) ) {
3324                         return false;
3325                 }
3326
3327                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3328                 # reachable due to the way web browsers deal with 'relative' URLs.
3329                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3330                 if (
3331                         strpos( $dbkey, '.' ) !== false &&
3332                         (
3333                                 $dbkey === '.' || $dbkey === '..' ||
3334                                 strpos( $dbkey, './' ) === 0 ||
3335                                 strpos( $dbkey, '../' ) === 0 ||
3336                                 strpos( $dbkey, '/./' ) !== false ||
3337                                 strpos( $dbkey, '/../' ) !== false ||
3338                                 substr( $dbkey, -2 ) == '/.' ||
3339                                 substr( $dbkey, -3 ) == '/..'
3340                         )
3341                 ) {
3342                         return false;
3343                 }
3344
3345                 # Magic tilde sequences? Nu-uh!
3346                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3347                         return false;
3348                 }
3349
3350                 # Limit the size of titles to 255 bytes. This is typically the size of the
3351                 # underlying database field. We make an exception for special pages, which
3352                 # don't need to be stored in the database, and may edge over 255 bytes due
3353                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3354                 if (
3355                         ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 )
3356                         || strlen( $dbkey ) > 512
3357                 ) {
3358                         return false;
3359                 }
3360
3361                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3362                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3363                 # other site might be case-sensitive.
3364                 $this->mUserCaseDBKey = $dbkey;
3365                 if ( !$this->isExternal() ) {
3366                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3367                 }
3368
3369                 # Can't make a link to a namespace alone... "empty" local links can only be
3370                 # self-links with a fragment identifier.
3371                 if ( $dbkey == '' && !$this->isExternal() && $this->mNamespace != NS_MAIN ) {
3372                         return false;
3373                 }
3374
3375                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3376                 // IP names are not allowed for accounts, and can only be referring to
3377                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3378                 // there are numerous ways to present the same IP. Having sp:contribs scan
3379                 // them all is silly and having some show the edits and others not is
3380                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3381                 if ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) {
3382                         $dbkey = IP::sanitizeIP( $dbkey );
3383                 }
3384
3385                 // Any remaining initial :s are illegal.
3386                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3387                         return false;
3388                 }
3389
3390                 # Fill fields
3391                 $this->mDbkeyform = $dbkey;
3392                 $this->mUrlform = wfUrlencode( $dbkey );
3393
3394                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3395
3396                 # We already know that some pages won't be in the database!
3397                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3398                         $this->mArticleID = 0;
3399                 }
3400
3401                 return true;
3402         }
3403
3404         /**
3405          * Get an array of Title objects linking to this Title
3406          * Also stores the IDs in the link cache.
3407          *
3408          * WARNING: do not use this function on arbitrary user-supplied titles!
3409          * On heavily-used templates it will max out the memory.
3410          *
3411          * @param array $options may be FOR UPDATE
3412          * @param string $table table name
3413          * @param string $prefix fields prefix
3414          * @return Array of Title objects linking here
3415          */
3416         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3417                 if ( count( $options ) > 0 ) {
3418                         $db = wfGetDB( DB_MASTER );
3419                 } else {
3420                         $db = wfGetDB( DB_SLAVE );
3421                 }
3422
3423                 $res = $db->select(
3424                         array( 'page', $table ),
3425                         self::getSelectFields(),
3426                         array(
3427                                 "{$prefix}_from=page_id",
3428                                 "{$prefix}_namespace" => $this->getNamespace(),
3429                                 "{$prefix}_title" => $this->getDBkey() ),
3430                         __METHOD__,
3431                         $options
3432                 );
3433
3434                 $retVal = array();
3435                 if ( $res->numRows() ) {
3436                         $linkCache = LinkCache::singleton();
3437                         foreach ( $res as $row ) {
3438                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3439                                 if ( $titleObj ) {
3440                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3441                                         $retVal[] = $titleObj;
3442                                 }
3443                         }
3444                 }
3445                 return $retVal;
3446         }
3447
3448         /**
3449          * Get an array of Title objects using 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 Array of Title the Title objects linking here
3457          */
3458         public function getTemplateLinksTo( $options = array() ) {
3459                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3460         }
3461
3462         /**
3463          * Get an array of Title objects linked from this Title
3464          * Also stores the IDs in the link cache.
3465          *
3466          * WARNING: do not use this function on arbitrary user-supplied titles!
3467          * On heavily-used templates it will max out the memory.
3468          *
3469          * @param array $options may be FOR UPDATE
3470          * @param string $table table name
3471          * @param string $prefix fields prefix
3472          * @return Array of Title objects linking here
3473          */
3474         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3475                 global $wgContentHandlerUseDB;
3476
3477                 $id = $this->getArticleID();
3478
3479                 # If the page doesn't exist; there can't be any link from this page
3480                 if ( !$id ) {
3481                         return array();
3482                 }
3483
3484                 if ( count( $options ) > 0 ) {
3485                         $db = wfGetDB( DB_MASTER );
3486                 } else {
3487                         $db = wfGetDB( DB_SLAVE );
3488                 }
3489
3490                 $namespaceFiled = "{$prefix}_namespace";
3491                 $titleField = "{$prefix}_title";
3492
3493                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3494                 if ( $wgContentHandlerUseDB ) {
3495                         $fields[] = 'page_content_model';
3496                 }
3497
3498                 $res = $db->select(
3499                         array( $table, 'page' ),
3500                         $fields,
3501                         array( "{$prefix}_from" => $id ),
3502                         __METHOD__,
3503                         $options,
3504                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3505                 );
3506
3507                 $retVal = array();
3508                 if ( $res->numRows() ) {
3509                         $linkCache = LinkCache::singleton();
3510                         foreach ( $res as $row ) {
3511                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3512                                 if ( $titleObj ) {
3513                                         if ( $row->page_id ) {
3514                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3515                                         } else {
3516                                                 $linkCache->addBadLinkObj( $titleObj );
3517                                         }
3518                                         $retVal[] = $titleObj;
3519                                 }
3520                         }
3521                 }
3522                 return $retVal;
3523         }
3524
3525         /**
3526          * Get an array of Title objects used on this Title as a template
3527          * Also stores the IDs in the link cache.
3528          *
3529          * WARNING: do not use this function on arbitrary user-supplied titles!
3530          * On heavily-used templates it will max out the memory.
3531          *
3532          * @param array $options may be FOR UPDATE
3533          * @return Array of Title the Title objects used here
3534          */
3535         public function getTemplateLinksFrom( $options = array() ) {
3536                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3537         }
3538
3539         /**
3540          * Get an array of Title objects referring to non-existent articles linked from this page
3541          *
3542          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3543          * @return Array of Title the Title objects
3544          */
3545         public function getBrokenLinksFrom() {
3546                 if ( $this->getArticleID() == 0 ) {
3547                         # All links from article ID 0 are false positives
3548                         return array();
3549                 }
3550
3551                 $dbr = wfGetDB( DB_SLAVE );
3552                 $res = $dbr->select(
3553                         array( 'page', 'pagelinks' ),
3554                         array( 'pl_namespace', 'pl_title' ),
3555                         array(
3556                                 'pl_from' => $this->getArticleID(),
3557                                 'page_namespace IS NULL'
3558                         ),
3559                         __METHOD__, array(),
3560                         array(
3561                                 'page' => array(
3562                                         'LEFT JOIN',
3563                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3564                                 )
3565                         )
3566                 );
3567
3568                 $retVal = array();
3569                 foreach ( $res as $row ) {
3570                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3571                 }
3572                 return $retVal;
3573         }
3574
3575         /**
3576          * Get a list of URLs to purge from the Squid cache when this
3577          * page changes
3578          *
3579          * @return Array of String the URLs
3580          */
3581         public function getSquidURLs() {
3582                 $urls = array(
3583                         $this->getInternalURL(),
3584                         $this->getInternalURL( 'action=history' )
3585                 );
3586
3587                 $pageLang = $this->getPageLanguage();
3588                 if ( $pageLang->hasVariants() ) {
3589                         $variants = $pageLang->getVariants();
3590                         foreach ( $variants as $vCode ) {
3591                                 $urls[] = $this->getInternalURL( '', $vCode );
3592                         }
3593                 }
3594
3595                 // If we are looking at a css/js user subpage, purge the action=raw.
3596                 if ( $this->isJsSubpage() ) {
3597                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3598                 } elseif ( $this->isCssSubpage() ) {
3599                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3600                 }
3601
3602                 wfRunHooks( 'TitleSquidURLs', array( $this, &$urls ) );
3603                 return $urls;
3604         }
3605
3606         /**
3607          * Purge all applicable Squid URLs
3608          */
3609         public function purgeSquid() {
3610                 global $wgUseSquid;
3611                 if ( $wgUseSquid ) {
3612                         $urls = $this->getSquidURLs();
3613                         $u = new SquidUpdate( $urls );
3614                         $u->doUpdate();
3615                 }
3616         }
3617
3618         /**
3619          * Move this page without authentication
3620          *
3621          * @param $nt Title the new page Title
3622          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3623          */
3624         public function moveNoAuth( &$nt ) {
3625                 return $this->moveTo( $nt, false );
3626         }
3627
3628         /**
3629          * Check whether a given move operation would be valid.
3630          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3631          *
3632          * @param $nt Title the new title
3633          * @param bool $auth indicates whether $wgUser's permissions
3634          *  should be checked
3635          * @param string $reason is the log summary of the move, used for spam checking
3636          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3637          */
3638         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3639                 global $wgUser, $wgContentHandlerUseDB;
3640
3641                 $errors = array();
3642                 if ( !$nt ) {
3643                         // Normally we'd add this to $errors, but we'll get
3644                         // lots of syntax errors if $nt is not an object
3645                         return array( array( 'badtitletext' ) );
3646                 }
3647                 if ( $this->equals( $nt ) ) {
3648                         $errors[] = array( 'selfmove' );
3649                 }
3650                 if ( !$this->isMovable() ) {
3651                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3652                 }
3653                 if ( $nt->isExternal() ) {
3654                         $errors[] = array( 'immobile-target-namespace-iw' );
3655                 }
3656                 if ( !$nt->isMovable() ) {
3657                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3658                 }
3659
3660                 $oldid = $this->getArticleID();
3661                 $newid = $nt->getArticleID();
3662
3663                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3664                         $errors[] = array( 'articleexists' );
3665                 }
3666                 if (
3667                         ( $this->getDBkey() == '' ) ||
3668                         ( !$oldid ) ||
3669                         ( $nt->getDBkey() == '' )
3670                 ) {
3671                         $errors[] = array( 'badarticleerror' );
3672                 }
3673
3674                 // Content model checks
3675                 if ( !$wgContentHandlerUseDB &&
3676                                 $this->getContentModel() !== $nt->getContentModel() ) {
3677                         // can't move a page if that would change the page's content model
3678                         $errors[] = array(
3679                                 'bad-target-model',
3680                                 ContentHandler::getLocalizedName( $this->getContentModel() ),
3681                                 ContentHandler::getLocalizedName( $nt->getContentModel() )
3682                         );
3683                 }
3684
3685                 // Image-specific checks
3686                 if ( $this->getNamespace() == NS_FILE ) {
3687                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3688                 }
3689
3690                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3691                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3692                 }
3693
3694                 if ( $auth ) {
3695                         $errors = wfMergeErrorArrays( $errors,
3696                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3697                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3698                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3699                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3700                 }
3701
3702                 $match = EditPage::matchSummarySpamRegex( $reason );
3703                 if ( $match !== false ) {
3704                         // This is kind of lame, won't display nice
3705                         $errors[] = array( 'spamprotectiontext' );
3706                 }
3707
3708                 $err = null;
3709                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3710                         $errors[] = array( 'hookaborted', $err );
3711                 }
3712
3713                 # The move is allowed only if (1) the target doesn't exist, or
3714                 # (2) the target is a redirect to the source, and has no history
3715                 # (so we can undo bad moves right after they're done).
3716
3717                 if ( 0 != $newid ) { # Target exists; check for validity
3718                         if ( !$this->isValidMoveTarget( $nt ) ) {
3719                                 $errors[] = array( 'articleexists' );
3720                         }
3721                 } else {
3722                         $tp = $nt->getTitleProtection();
3723                         $right = $tp['pt_create_perm'];
3724                         if ( $right == 'sysop' ) {
3725                                 $right = 'editprotected'; // B/C
3726                         }
3727                         if ( $right == 'autoconfirmed' ) {
3728                                 $right = 'editsemiprotected'; // B/C
3729                         }
3730                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3731                                 $errors[] = array( 'cantmove-titleprotected' );
3732                         }
3733                 }
3734                 if ( empty( $errors ) ) {
3735                         return true;
3736                 }
3737                 return $errors;
3738         }
3739
3740         /**
3741          * Check if the requested move target is a valid file move target
3742          * @param Title $nt Target title
3743          * @return array List of errors
3744          */
3745         protected function validateFileMoveOperation( $nt ) {
3746                 global $wgUser;
3747
3748                 $errors = array();
3749
3750                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3751
3752                 $file = wfLocalFile( $this );
3753                 if ( $file->exists() ) {
3754                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3755                                 $errors[] = array( 'imageinvalidfilename' );
3756                         }
3757                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3758                                 $errors[] = array( 'imagetypemismatch' );
3759                         }
3760                 }
3761
3762                 if ( $nt->getNamespace() != NS_FILE ) {
3763                         $errors[] = array( 'imagenocrossnamespace' );
3764                         // From here we want to do checks on a file object, so if we can't
3765                         // create one, we must return.
3766                         return $errors;
3767                 }
3768
3769                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3770
3771                 $destFile = wfLocalFile( $nt );
3772                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3773                         $errors[] = array( 'file-exists-sharedrepo' );
3774                 }
3775
3776                 return $errors;
3777         }
3778
3779         /**
3780          * Move a title to a new location
3781          *
3782          * @param $nt Title the new title
3783          * @param bool $auth indicates whether $wgUser's permissions
3784          *  should be checked
3785          * @param string $reason the reason for the move
3786          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3787          *  Ignored if the user doesn't have the suppressredirect right.
3788          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3789          */
3790         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3791                 global $wgUser;
3792                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3793                 if ( is_array( $err ) ) {
3794                         // Auto-block user's IP if the account was "hard" blocked
3795                         $wgUser->spreadAnyEditBlock();
3796                         return $err;
3797                 }
3798                 // Check suppressredirect permission
3799                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3800                         $createRedirect = true;
3801                 }
3802
3803                 wfRunHooks( 'TitleMove', array( $this, $nt, $wgUser ) );
3804
3805                 // If it is a file, move it first.
3806                 // It is done before all other moving stuff is done because it's hard to revert.
3807                 $dbw = wfGetDB( DB_MASTER );
3808                 if ( $this->getNamespace() == NS_FILE ) {
3809                         $file = wfLocalFile( $this );
3810                         if ( $file->exists() ) {
3811                                 $status = $file->move( $nt );
3812                                 if ( !$status->isOk() ) {
3813                                         return $status->getErrorsArray();
3814                                 }
3815                         }
3816                         // Clear RepoGroup process cache
3817                         RepoGroup::singleton()->clearCache( $this );
3818                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3819                 }
3820
3821                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3822                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3823                 $protected = $this->isProtected();
3824
3825                 // Do the actual move
3826                 $this->moveToInternal( $nt, $reason, $createRedirect );
3827
3828                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3829                 // cl_timestamp, which may disturb time-based lists on some sites.
3830                 $prefixes = $dbw->select(
3831                         'categorylinks',
3832                         array( 'cl_sortkey_prefix', 'cl_to' ),
3833                         array( 'cl_from' => $pageid ),
3834                         __METHOD__
3835                 );
3836                 foreach ( $prefixes as $prefixRow ) {
3837                         $prefix = $prefixRow->cl_sortkey_prefix;
3838                         $catTo = $prefixRow->cl_to;
3839                         $dbw->update( 'categorylinks',
3840                                 array(
3841                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3842                                                 $nt->getCategorySortkey( $prefix ) ),
3843                                         'cl_timestamp=cl_timestamp' ),
3844                                 array(
3845                                         'cl_from' => $pageid,
3846                                         'cl_to' => $catTo ),
3847                                 __METHOD__
3848                         );
3849                 }
3850
3851                 $redirid = $this->getArticleID();
3852
3853                 if ( $protected ) {
3854                         # Protect the redirect title as the title used to be...
3855                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3856                                 array(
3857                                         'pr_page' => $redirid,
3858                                         'pr_type' => 'pr_type',
3859                                         'pr_level' => 'pr_level',
3860                                         'pr_cascade' => 'pr_cascade',
3861                                         'pr_user' => 'pr_user',
3862                                         'pr_expiry' => 'pr_expiry'
3863                                 ),
3864                                 array( 'pr_page' => $pageid ),
3865                                 __METHOD__,
3866                                 array( 'IGNORE' )
3867                         );
3868                         # Update the protection log
3869                         $log = new LogPage( 'protect' );
3870                         $comment = wfMessage(
3871                                 'prot_1movedto2',
3872                                 $this->getPrefixedText(),
3873                                 $nt->getPrefixedText()
3874                         )->inContentLanguage()->text();
3875                         if ( $reason ) {
3876                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3877                         }
3878                         // @todo FIXME: $params?
3879                         $logId = $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ), $wgUser );
3880
3881                         // reread inserted pr_ids for log relation
3882                         $insertedPrIds = $dbw->select(
3883                                 'page_restrictions',
3884                                 'pr_id',
3885                                 array( 'pr_page' => $redirid ),
3886                                 __METHOD__
3887                         );
3888                         $logRelationsValues = array();
3889                         foreach ( $insertedPrIds as $prid ) {
3890                                 $logRelationsValues[] = $prid->pr_id;
3891                         }
3892                         $log->addRelations( 'pr_id', $logRelationsValues, $logId );
3893                 }
3894
3895                 # Update watchlists
3896                 $oldnamespace = MWNamespace::getSubject( $this->getNamespace() );
3897                 $newnamespace = MWNamespace::getSubject( $nt->getNamespace() );
3898                 $oldtitle = $this->getDBkey();
3899                 $newtitle = $nt->getDBkey();
3900
3901                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3902                         WatchedItem::duplicateEntries( $this, $nt );
3903                 }
3904
3905                 $dbw->commit( __METHOD__ );
3906
3907                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3908                 return true;
3909         }
3910
3911         /**
3912          * Move page to a title which is either a redirect to the
3913          * source page or nonexistent
3914          *
3915          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3916          * @param string $reason The reason for the move
3917          * @param bool $createRedirect Whether to leave a redirect at the old title. Does not check
3918          *   if the user has the suppressredirect right
3919          * @throws MWException
3920          */
3921         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3922                 global $wgUser, $wgContLang;
3923
3924                 if ( $nt->exists() ) {
3925                         $moveOverRedirect = true;
3926                         $logType = 'move_redir';
3927                 } else {
3928                         $moveOverRedirect = false;
3929                         $logType = 'move';
3930                 }
3931
3932                 if ( $createRedirect ) {
3933                         $contentHandler = ContentHandler::getForTitle( $this );
3934                         $redirectContent = $contentHandler->makeRedirectContent( $nt,
3935                                 wfMessage( 'move-redirect-text' )->inContentLanguage()->plain() );
3936
3937                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3938                 } else {
3939                         $redirectContent = null;
3940                 }
3941
3942                 $logEntry = new ManualLogEntry( 'move', $logType );
3943                 $logEntry->setPerformer( $wgUser );
3944                 $logEntry->setTarget( $this );
3945                 $logEntry->setComment( $reason );
3946                 $logEntry->setParameters( array(
3947                         '4::target' => $nt->getPrefixedText(),
3948                         '5::noredir' => $redirectContent ? '0': '1',
3949                 ) );
3950
3951                 $formatter = LogFormatter::newFromEntry( $logEntry );
3952                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3953                 $comment = $formatter->getPlainActionText();
3954                 if ( $reason ) {
3955                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3956                 }
3957                 # Truncate for whole multibyte characters.
3958                 $comment = $wgContLang->truncate( $comment, 255 );
3959
3960                 $oldid = $this->getArticleID();
3961
3962                 $dbw = wfGetDB( DB_MASTER );
3963
3964                 $newpage = WikiPage::factory( $nt );
3965
3966                 if ( $moveOverRedirect ) {
3967                         $newid = $nt->getArticleID();
3968                         $newcontent = $newpage->getContent();
3969
3970                         # Delete the old redirect. We don't save it to history since
3971                         # by definition if we've got here it's rather uninteresting.
3972                         # We have to remove it so that the next step doesn't trigger
3973                         # a conflict on the unique namespace+title index...
3974                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3975
3976                         $newpage->doDeleteUpdates( $newid, $newcontent );
3977                 }
3978
3979                 # Save a null revision in the page's history notifying of the move
3980                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3981                 if ( !is_object( $nullRevision ) ) {
3982                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3983                 }
3984
3985                 $nullRevision->insertOn( $dbw );
3986
3987                 # Change the name of the target page:
3988                 $dbw->update( 'page',
3989                         /* SET */ array(
3990                                 'page_namespace' => $nt->getNamespace(),
3991                                 'page_title' => $nt->getDBkey(),
3992                         ),
3993                         /* WHERE */ array( 'page_id' => $oldid ),
3994                         __METHOD__
3995                 );
3996
3997                 // clean up the old title before reset article id - bug 45348
3998                 if ( !$redirectContent ) {
3999                         WikiPage::onArticleDelete( $this );
4000                 }
4001
4002                 $this->resetArticleID( 0 ); // 0 == non existing
4003                 $nt->resetArticleID( $oldid );
4004                 $newpage->loadPageData( WikiPage::READ_LOCKING ); // bug 46397
4005
4006                 $newpage->updateRevisionOn( $dbw, $nullRevision );
4007
4008                 wfRunHooks( 'NewRevisionFromEditComplete',
4009                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
4010
4011                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
4012
4013                 if ( !$moveOverRedirect ) {
4014                         WikiPage::onArticleCreate( $nt );
4015                 }
4016
4017                 # Recreate the redirect, this time in the other direction.
4018                 if ( $redirectContent ) {
4019                         $redirectArticle = WikiPage::factory( $this );
4020                         $redirectArticle->loadFromRow( false, WikiPage::READ_LOCKING ); // bug 46397
4021                         $newid = $redirectArticle->insertOn( $dbw );
4022                         if ( $newid ) { // sanity
4023                                 $this->resetArticleID( $newid );
4024                                 $redirectRevision = new Revision( array(
4025                                         'title' => $this, // for determining the default content model
4026                                         'page' => $newid,
4027                                         'comment' => $comment,
4028                                         'content' => $redirectContent ) );
4029                                 $redirectRevision->insertOn( $dbw );
4030                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
4031
4032                                 wfRunHooks( 'NewRevisionFromEditComplete',
4033                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
4034
4035                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
4036                         }
4037                 }
4038
4039                 # Log the move
4040                 $logid = $logEntry->insert();
4041                 $logEntry->publish( $logid );
4042         }
4043
4044         /**
4045          * Move this page's subpages to be subpages of $nt
4046          *
4047          * @param $nt Title Move target
4048          * @param bool $auth Whether $wgUser's permissions should be checked
4049          * @param string $reason The reason for the move
4050          * @param bool $createRedirect Whether to create redirects from the old subpages to
4051          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
4052          * @return mixed array with old page titles as keys, and strings (new page titles) or
4053          *     arrays (errors) as values, or an error array with numeric indices if no pages
4054          *     were moved
4055          */
4056         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
4057                 global $wgMaximumMovedPages;
4058                 // Check permissions
4059                 if ( !$this->userCan( 'move-subpages' ) ) {
4060                         return array( 'cant-move-subpages' );
4061                 }
4062                 // Do the source and target namespaces support subpages?
4063                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4064                         return array( 'namespace-nosubpages',
4065                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
4066                 }
4067                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
4068                         return array( 'namespace-nosubpages',
4069                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
4070                 }
4071
4072                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
4073                 $retval = array();
4074                 $count = 0;
4075                 foreach ( $subpages as $oldSubpage ) {
4076                         $count++;
4077                         if ( $count > $wgMaximumMovedPages ) {
4078                                 $retval[$oldSubpage->getPrefixedText()] =
4079                                                 array( 'movepage-max-pages',
4080                                                         $wgMaximumMovedPages );
4081                                 break;
4082                         }
4083
4084                         // We don't know whether this function was called before
4085                         // or after moving the root page, so check both
4086                         // $this and $nt
4087                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
4088                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
4089                         ) {
4090                                 // When moving a page to a subpage of itself,
4091                                 // don't move it twice
4092                                 continue;
4093                         }
4094                         $newPageName = preg_replace(
4095                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
4096                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
4097                                         $oldSubpage->getDBkey() );
4098                         if ( $oldSubpage->isTalkPage() ) {
4099                                 $newNs = $nt->getTalkPage()->getNamespace();
4100                         } else {
4101                                 $newNs = $nt->getSubjectPage()->getNamespace();
4102                         }
4103                         # Bug 14385: we need makeTitleSafe because the new page names may
4104                         # be longer than 255 characters.
4105                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
4106
4107                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
4108                         if ( $success === true ) {
4109                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
4110                         } else {
4111                                 $retval[$oldSubpage->getPrefixedText()] = $success;
4112                         }
4113                 }
4114                 return $retval;
4115         }
4116
4117         /**
4118          * Checks if this page is just a one-rev redirect.
4119          * Adds lock, so don't use just for light purposes.
4120          *
4121          * @return Bool
4122          */
4123         public function isSingleRevRedirect() {
4124                 global $wgContentHandlerUseDB;
4125
4126                 $dbw = wfGetDB( DB_MASTER );
4127
4128                 # Is it a redirect?
4129                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
4130                 if ( $wgContentHandlerUseDB ) {
4131                         $fields[] = 'page_content_model';
4132                 }
4133
4134                 $row = $dbw->selectRow( 'page',
4135                         $fields,
4136                         $this->pageCond(),
4137                         __METHOD__,
4138                         array( 'FOR UPDATE' )
4139                 );
4140                 # Cache some fields we may want
4141                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
4142                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
4143                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
4144                 $this->mContentModel = $row && isset( $row->page_content_model ) ? strval( $row->page_content_model ) : false;
4145                 if ( !$this->mRedirect ) {
4146                         return false;
4147                 }
4148                 # Does the article have a history?
4149                 $row = $dbw->selectField( array( 'page', 'revision' ),
4150                         'rev_id',
4151                         array( 'page_namespace' => $this->getNamespace(),
4152                                 'page_title' => $this->getDBkey(),
4153                                 'page_id=rev_page',
4154                                 'page_latest != rev_id'
4155                         ),
4156                         __METHOD__,
4157                         array( 'FOR UPDATE' )
4158                 );
4159                 # Return true if there was no history
4160                 return ( $row === false );
4161         }
4162
4163         /**
4164          * Checks if $this can be moved to a given Title
4165          * - Selects for update, so don't call it unless you mean business
4166          *
4167          * @param $nt Title the new title to check
4168          * @return Bool
4169          */
4170         public function isValidMoveTarget( $nt ) {
4171                 # Is it an existing file?
4172                 if ( $nt->getNamespace() == NS_FILE ) {
4173                         $file = wfLocalFile( $nt );
4174                         if ( $file->exists() ) {
4175                                 wfDebug( __METHOD__ . ": file exists\n" );
4176                                 return false;
4177                         }
4178                 }
4179                 # Is it a redirect with no history?
4180                 if ( !$nt->isSingleRevRedirect() ) {
4181                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
4182                         return false;
4183                 }
4184                 # Get the article text
4185                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
4186                 if ( !is_object( $rev ) ) {
4187                         return false;
4188                 }
4189                 $content = $rev->getContent();
4190                 # Does the redirect point to the source?
4191                 # Or is it a broken self-redirect, usually caused by namespace collisions?
4192                 $redirTitle = $content ? $content->getRedirectTarget() : null;
4193
4194                 if ( $redirTitle ) {
4195                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
4196                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
4197                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
4198                                 return false;
4199                         } else {
4200                                 return true;
4201                         }
4202                 } else {
4203                         # Fail safe (not a redirect after all. strange.)
4204                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
4205                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
4206                         return false;
4207                 }
4208         }
4209
4210         /**
4211          * Get categories to which this Title belongs and return an array of
4212          * categories' names.
4213          *
4214          * @return Array of parents in the form:
4215          *        $parent => $currentarticle
4216          */
4217         public function getParentCategories() {
4218                 global $wgContLang;
4219
4220                 $data = array();
4221
4222                 $titleKey = $this->getArticleID();
4223
4224                 if ( $titleKey === 0 ) {
4225                         return $data;
4226                 }
4227
4228                 $dbr = wfGetDB( DB_SLAVE );
4229
4230                 $res = $dbr->select(
4231                         'categorylinks',
4232                         'cl_to',
4233                         array( 'cl_from' => $titleKey ),
4234                         __METHOD__
4235                 );
4236
4237                 if ( $res->numRows() > 0 ) {
4238                         foreach ( $res as $row ) {
4239                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
4240                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4241                         }
4242                 }
4243                 return $data;
4244         }
4245
4246         /**
4247          * Get a tree of parent categories
4248          *
4249          * @param array $children with the children in the keys, to check for circular refs
4250          * @return Array Tree of parent categories
4251          */
4252         public function getParentCategoryTree( $children = array() ) {
4253                 $stack = array();
4254                 $parents = $this->getParentCategories();
4255
4256                 if ( $parents ) {
4257                         foreach ( $parents as $parent => $current ) {
4258                                 if ( array_key_exists( $parent, $children ) ) {
4259                                         # Circular reference
4260                                         $stack[$parent] = array();
4261                                 } else {
4262                                         $nt = Title::newFromText( $parent );
4263                                         if ( $nt ) {
4264                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4265                                         }
4266                                 }
4267                         }
4268                 }
4269
4270                 return $stack;
4271         }
4272
4273         /**
4274          * Get an associative array for selecting this title from
4275          * the "page" table
4276          *
4277          * @return Array suitable for the $where parameter of DB::select()
4278          */
4279         public function pageCond() {
4280                 if ( $this->mArticleID > 0 ) {
4281                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4282                         return array( 'page_id' => $this->mArticleID );
4283                 } else {
4284                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4285                 }
4286         }
4287
4288         /**
4289          * Get the revision ID of the previous revision
4290          *
4291          * @param int $revId Revision ID. Get the revision that was before this one.
4292          * @param int $flags Title::GAID_FOR_UPDATE
4293          * @return Int|Bool Old revision ID, or FALSE if none exists
4294          */
4295         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4296                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4297                 $revId = $db->selectField( 'revision', 'rev_id',
4298                         array(
4299                                 'rev_page' => $this->getArticleID( $flags ),
4300                                 'rev_id < ' . intval( $revId )
4301                         ),
4302                         __METHOD__,
4303                         array( 'ORDER BY' => 'rev_id DESC' )
4304                 );
4305
4306                 if ( $revId === false ) {
4307                         return false;
4308                 } else {
4309                         return intval( $revId );
4310                 }
4311         }
4312
4313         /**
4314          * Get the revision ID of the next revision
4315          *
4316          * @param int $revId Revision ID. Get the revision that was after this one.
4317          * @param int $flags Title::GAID_FOR_UPDATE
4318          * @return Int|Bool Next revision ID, or FALSE if none exists
4319          */
4320         public function getNextRevisionID( $revId, $flags = 0 ) {
4321                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4322                 $revId = $db->selectField( 'revision', 'rev_id',
4323                         array(
4324                                 'rev_page' => $this->getArticleID( $flags ),
4325                                 'rev_id > ' . intval( $revId )
4326                         ),
4327                         __METHOD__,
4328                         array( 'ORDER BY' => 'rev_id' )
4329                 );
4330
4331                 if ( $revId === false ) {
4332                         return false;
4333                 } else {
4334                         return intval( $revId );
4335                 }
4336         }
4337
4338         /**
4339          * Get the first revision of the page
4340          *
4341          * @param int $flags Title::GAID_FOR_UPDATE
4342          * @return Revision|Null if page doesn't exist
4343          */
4344         public function getFirstRevision( $flags = 0 ) {
4345                 $pageId = $this->getArticleID( $flags );
4346                 if ( $pageId ) {
4347                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4348                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4349                                 array( 'rev_page' => $pageId ),
4350                                 __METHOD__,
4351                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4352                         );
4353                         if ( $row ) {
4354                                 return new Revision( $row );
4355                         }
4356                 }
4357                 return null;
4358         }
4359
4360         /**
4361          * Get the oldest revision timestamp of this page
4362          *
4363          * @param int $flags Title::GAID_FOR_UPDATE
4364          * @return String: MW timestamp
4365          */
4366         public function getEarliestRevTime( $flags = 0 ) {
4367                 $rev = $this->getFirstRevision( $flags );
4368                 return $rev ? $rev->getTimestamp() : null;
4369         }
4370
4371         /**
4372          * Check if this is a new page
4373          *
4374          * @return bool
4375          */
4376         public function isNewPage() {
4377                 $dbr = wfGetDB( DB_SLAVE );
4378                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4379         }
4380
4381         /**
4382          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4383          *
4384          * @return bool
4385          */
4386         public function isBigDeletion() {
4387                 global $wgDeleteRevisionsLimit;
4388
4389                 if ( !$wgDeleteRevisionsLimit ) {
4390                         return false;
4391                 }
4392
4393                 $revCount = $this->estimateRevisionCount();
4394                 return $revCount > $wgDeleteRevisionsLimit;
4395         }
4396
4397         /**
4398          * Get the  approximate revision count of this page.
4399          *
4400          * @return int
4401          */
4402         public function estimateRevisionCount() {
4403                 if ( !$this->exists() ) {
4404                         return 0;
4405                 }
4406
4407                 if ( $this->mEstimateRevisions === null ) {
4408                         $dbr = wfGetDB( DB_SLAVE );
4409                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4410                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4411                 }
4412
4413                 return $this->mEstimateRevisions;
4414         }
4415
4416         /**
4417          * Get the number of revisions between the given revision.
4418          * Used for diffs and other things that really need it.
4419          *
4420          * @param int|Revision $old Old revision or rev ID (first before range)
4421          * @param int|Revision $new New revision or rev ID (first after range)
4422          * @return Int Number of revisions between these revisions.
4423          */
4424         public function countRevisionsBetween( $old, $new ) {
4425                 if ( !( $old instanceof Revision ) ) {
4426                         $old = Revision::newFromTitle( $this, (int)$old );
4427                 }
4428                 if ( !( $new instanceof Revision ) ) {
4429                         $new = Revision::newFromTitle( $this, (int)$new );
4430                 }
4431                 if ( !$old || !$new ) {
4432                         return 0; // nothing to compare
4433                 }
4434                 $dbr = wfGetDB( DB_SLAVE );
4435                 return (int)$dbr->selectField( 'revision', 'count(*)',
4436                         array(
4437                                 'rev_page' => $this->getArticleID(),
4438                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4439                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4440                         ),
4441                         __METHOD__
4442                 );
4443         }
4444
4445         /**
4446          * Get the authors between the given revisions or revision IDs.
4447          * Used for diffs and other things that really need it.
4448          *
4449          * @since 1.23
4450          *
4451          * @param int|Revision $old Old revision or rev ID (first before range by default)
4452          * @param int|Revision $new New revision or rev ID (first after range by default)
4453          * @param int $limit Maximum number of authors
4454          * @param string|array $options (Optional): Single option, or an array of options:
4455          *     'include_old' Include $old in the range; $new is excluded.
4456          *     'include_new' Include $new in the range; $old is excluded.
4457          *     'include_both' Include both $old and $new in the range.
4458          *     Unknown option values are ignored.
4459          * @return array|null Names of revision authors in the range; null if not both revisions exist
4460          */
4461         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4462                 if ( !( $old instanceof Revision ) ) {
4463                         $old = Revision::newFromTitle( $this, (int)$old );
4464                 }
4465                 if ( !( $new instanceof Revision ) ) {
4466                         $new = Revision::newFromTitle( $this, (int)$new );
4467                 }
4468                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4469                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4470                 // in the sanity check below?
4471                 if ( !$old || !$new ) {
4472                         return null; // nothing to compare
4473                 }
4474                 $authors = array();
4475                 $old_cmp = '>';
4476                 $new_cmp = '<';
4477                 $options = (array)$options;
4478                 if ( in_array( 'include_old', $options ) ) {
4479                         $old_cmp = '>=';
4480                 }
4481                 if ( in_array( 'include_new', $options ) ) {
4482                         $new_cmp = '<=';
4483                 }
4484                 if ( in_array( 'include_both', $options ) ) {
4485                         $old_cmp = '>=';
4486                         $new_cmp = '<=';
4487                 }
4488                 // No DB query needed if $old and $new are the same or successive revisions:
4489                 if ( $old->getId() === $new->getId() ) {
4490                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? array() : array( $old->getRawUserText() );
4491                 } elseif ( $old->getId() === $new->getParentId() ) {
4492                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4493                                 $authors[] = $old->getRawUserText();
4494                                 if ( $old->getRawUserText() != $new->getRawUserText() ) {
4495                                         $authors[] = $new->getRawUserText();
4496                                 }
4497                         } elseif ( $old_cmp === '>=' ) {
4498                                 $authors[] = $old->getRawUserText();
4499                         } elseif ( $new_cmp === '<=' ) {
4500                                 $authors[] = $new->getRawUserText();
4501                         }
4502                         return $authors;
4503                 }
4504                 $dbr = wfGetDB( DB_SLAVE );
4505                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4506                         array(
4507                                 'rev_page' => $this->getArticleID(),
4508                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4509                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4510                         ), __METHOD__,
4511                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4512                 );
4513                 foreach ( $res as $row ) {
4514                         $authors[] = $row->rev_user_text;
4515                 }
4516                 return $authors;
4517         }
4518
4519         /**
4520          * Get the number of authors between the given revisions or revision IDs.
4521          * Used for diffs and other things that really need it.
4522          *
4523          * @param int|Revision $old Old revision or rev ID (first before range by default)
4524          * @param int|Revision $new New revision or rev ID (first after range by default)
4525          * @param int $limit Maximum number of authors
4526          * @param string|array $options (Optional): Single option, or an array of options:
4527          *     'include_old' Include $old in the range; $new is excluded.
4528          *     'include_new' Include $new in the range; $old is excluded.
4529          *     'include_both' Include both $old and $new in the range.
4530          *     Unknown option values are ignored.
4531          * @return int Number of revision authors in the range; zero if not both revisions exist
4532          */
4533         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4534                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4535                 return $authors ? count( $authors ) : 0;
4536         }
4537
4538         /**
4539          * Compare with another title.
4540          *
4541          * @param $title Title
4542          * @return Bool
4543          */
4544         public function equals( Title $title ) {
4545                 // Note: === is necessary for proper matching of number-like titles.
4546                 return $this->getInterwiki() === $title->getInterwiki()
4547                         && $this->getNamespace() == $title->getNamespace()
4548                         && $this->getDBkey() === $title->getDBkey();
4549         }
4550
4551         /**
4552          * Check if this title is a subpage of another title
4553          *
4554          * @param $title Title
4555          * @return Bool
4556          */
4557         public function isSubpageOf( Title $title ) {
4558                 return $this->getInterwiki() === $title->getInterwiki()
4559                         && $this->getNamespace() == $title->getNamespace()
4560                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4561         }
4562
4563         /**
4564          * Check if page exists.  For historical reasons, this function simply
4565          * checks for the existence of the title in the page table, and will
4566          * thus return false for interwiki links, special pages and the like.
4567          * If you want to know if a title can be meaningfully viewed, you should
4568          * probably call the isKnown() method instead.
4569          *
4570          * @return Bool
4571          */
4572         public function exists() {
4573                 return $this->getArticleID() != 0;
4574         }
4575
4576         /**
4577          * Should links to this title be shown as potentially viewable (i.e. as
4578          * "bluelinks"), even if there's no record by this title in the page
4579          * table?
4580          *
4581          * This function is semi-deprecated for public use, as well as somewhat
4582          * misleadingly named.  You probably just want to call isKnown(), which
4583          * calls this function internally.
4584          *
4585          * (ISSUE: Most of these checks are cheap, but the file existence check
4586          * can potentially be quite expensive.  Including it here fixes a lot of
4587          * existing code, but we might want to add an optional parameter to skip
4588          * it and any other expensive checks.)
4589          *
4590          * @return Bool
4591          */
4592         public function isAlwaysKnown() {
4593                 $isKnown = null;
4594
4595                 /**
4596                  * Allows overriding default behavior for determining if a page exists.
4597                  * If $isKnown is kept as null, regular checks happen. If it's
4598                  * a boolean, this value is returned by the isKnown method.
4599                  *
4600                  * @since 1.20
4601                  *
4602                  * @param Title $title
4603                  * @param boolean|null $isKnown
4604                  */
4605                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4606
4607                 if ( !is_null( $isKnown ) ) {
4608                         return $isKnown;
4609                 }
4610
4611                 if ( $this->isExternal() ) {
4612                         return true;  // any interwiki link might be viewable, for all we know
4613                 }
4614
4615                 switch ( $this->mNamespace ) {
4616                         case NS_MEDIA:
4617                         case NS_FILE:
4618                                 // file exists, possibly in a foreign repo
4619                                 return (bool)wfFindFile( $this );
4620                         case NS_SPECIAL:
4621                                 // valid special page
4622                                 return SpecialPageFactory::exists( $this->getDBkey() );
4623                         case NS_MAIN:
4624                                 // selflink, possibly with fragment
4625                                 return $this->mDbkeyform == '';
4626                         case NS_MEDIAWIKI:
4627                                 // known system message
4628                                 return $this->hasSourceText() !== false;
4629                         default:
4630                                 return false;
4631                 }
4632         }
4633
4634         /**
4635          * Does this title refer to a page that can (or might) be meaningfully
4636          * viewed?  In particular, this function may be used to determine if
4637          * links to the title should be rendered as "bluelinks" (as opposed to
4638          * "redlinks" to non-existent pages).
4639          * Adding something else to this function will cause inconsistency
4640          * since LinkHolderArray calls isAlwaysKnown() and does its own
4641          * page existence check.
4642          *
4643          * @return Bool
4644          */
4645         public function isKnown() {
4646                 return $this->isAlwaysKnown() || $this->exists();
4647         }
4648
4649         /**
4650          * Does this page have source text?
4651          *
4652          * @return Boolean
4653          */
4654         public function hasSourceText() {
4655                 if ( $this->exists() ) {
4656                         return true;
4657                 }
4658
4659                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4660                         // If the page doesn't exist but is a known system message, default
4661                         // message content will be displayed, same for language subpages-
4662                         // Use always content language to avoid loading hundreds of languages
4663                         // to get the link color.
4664                         global $wgContLang;
4665                         list( $name, ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4666                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4667                         return $message->exists();
4668                 }
4669
4670                 return false;
4671         }
4672
4673         /**
4674          * Get the default message text or false if the message doesn't exist
4675          *
4676          * @return String or false
4677          */
4678         public function getDefaultMessageText() {
4679                 global $wgContLang;
4680
4681                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4682                         return false;
4683                 }
4684
4685                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4686                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4687
4688                 if ( $message->exists() ) {
4689                         return $message->plain();
4690                 } else {
4691                         return false;
4692                 }
4693         }
4694
4695         /**
4696          * Updates page_touched for this page; called from LinksUpdate.php
4697          *
4698          * @return Bool true if the update succeeded
4699          */
4700         public function invalidateCache() {
4701                 if ( wfReadOnly() ) {
4702                         return false;
4703                 }
4704
4705                 $method = __METHOD__;
4706                 $dbw = wfGetDB( DB_MASTER );
4707                 $conds = $this->pageCond();
4708                 $dbw->onTransactionIdle( function() use ( $dbw, $conds, $method ) {
4709                         $dbw->update(
4710                                 'page',
4711                                 array( 'page_touched' => $dbw->timestamp() ),
4712                                 $conds,
4713                                 $method
4714                         );
4715                 } );
4716
4717                 return true;
4718         }
4719
4720         /**
4721          * Update page_touched timestamps and send squid purge messages for
4722          * pages linking to this title. May be sent to the job queue depending
4723          * on the number of links. Typically called on create and delete.
4724          */
4725         public function touchLinks() {
4726                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4727                 $u->doUpdate();
4728
4729                 if ( $this->getNamespace() == NS_CATEGORY ) {
4730                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4731                         $u->doUpdate();
4732                 }
4733         }
4734
4735         /**
4736          * Get the last touched timestamp
4737          *
4738          * @param $db DatabaseBase: optional db
4739          * @return String last-touched timestamp
4740          */
4741         public function getTouched( $db = null ) {
4742                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4743                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4744                 return $touched;
4745         }
4746
4747         /**
4748          * Get the timestamp when this page was updated since the user last saw it.
4749          *
4750          * @param $user User
4751          * @return String|Null
4752          */
4753         public function getNotificationTimestamp( $user = null ) {
4754                 global $wgUser, $wgShowUpdatedMarker;
4755                 // Assume current user if none given
4756                 if ( !$user ) {
4757                         $user = $wgUser;
4758                 }
4759                 // Check cache first
4760                 $uid = $user->getId();
4761                 // avoid isset here, as it'll return false for null entries
4762                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4763                         return $this->mNotificationTimestamp[$uid];
4764                 }
4765                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4766                         $this->mNotificationTimestamp[$uid] = false;
4767                         return $this->mNotificationTimestamp[$uid];
4768                 }
4769                 // Don't cache too much!
4770                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4771                         $this->mNotificationTimestamp = array();
4772                 }
4773                 $dbr = wfGetDB( DB_SLAVE );
4774                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4775                         'wl_notificationtimestamp',
4776                         array(
4777                                 'wl_user' => $user->getId(),
4778                                 'wl_namespace' => $this->getNamespace(),
4779                                 'wl_title' => $this->getDBkey(),
4780                         ),
4781                         __METHOD__
4782                 );
4783                 return $this->mNotificationTimestamp[$uid];
4784         }
4785
4786         /**
4787          * Generate strings used for xml 'id' names in monobook tabs
4788          *
4789          * @param string $prepend defaults to 'nstab-'
4790          * @return String XML 'id' name
4791          */
4792         public function getNamespaceKey( $prepend = 'nstab-' ) {
4793                 global $wgContLang;
4794                 // Gets the subject namespace if this title
4795                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4796                 // Checks if canonical namespace name exists for namespace
4797                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4798                         // Uses canonical namespace name
4799                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4800                 } else {
4801                         // Uses text of namespace
4802                         $namespaceKey = $this->getSubjectNsText();
4803                 }
4804                 // Makes namespace key lowercase
4805                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4806                 // Uses main
4807                 if ( $namespaceKey == '' ) {
4808                         $namespaceKey = 'main';
4809                 }
4810                 // Changes file to image for backwards compatibility
4811                 if ( $namespaceKey == 'file' ) {
4812                         $namespaceKey = 'image';
4813                 }
4814                 return $prepend . $namespaceKey;
4815         }
4816
4817         /**
4818          * Get all extant redirects to this Title
4819          *
4820          * @param int|Null $ns Single namespace to consider; NULL to consider all namespaces
4821          * @return Title[] Array of Title redirects to this title
4822          */
4823         public function getRedirectsHere( $ns = null ) {
4824                 $redirs = array();
4825
4826                 $dbr = wfGetDB( DB_SLAVE );
4827                 $where = array(
4828                         'rd_namespace' => $this->getNamespace(),
4829                         'rd_title' => $this->getDBkey(),
4830                         'rd_from = page_id'
4831                 );
4832                 if ( $this->isExternal() ) {
4833                         $where['rd_interwiki'] = $this->getInterwiki();
4834                 } else {
4835                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4836                 }
4837                 if ( !is_null( $ns ) ) {
4838                         $where['page_namespace'] = $ns;
4839                 }
4840
4841                 $res = $dbr->select(
4842                         array( 'redirect', 'page' ),
4843                         array( 'page_namespace', 'page_title' ),
4844                         $where,
4845                         __METHOD__
4846                 );
4847
4848                 foreach ( $res as $row ) {
4849                         $redirs[] = self::newFromRow( $row );
4850                 }
4851                 return $redirs;
4852         }
4853
4854         /**
4855          * Check if this Title is a valid redirect target
4856          *
4857          * @return Bool
4858          */
4859         public function isValidRedirectTarget() {
4860                 global $wgInvalidRedirectTargets;
4861
4862                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4863                 if ( $this->isSpecial( 'Userlogout' ) ) {
4864                         return false;
4865                 }
4866
4867                 foreach ( $wgInvalidRedirectTargets as $target ) {
4868                         if ( $this->isSpecial( $target ) ) {
4869                                 return false;
4870                         }
4871                 }
4872
4873                 return true;
4874         }
4875
4876         /**
4877          * Get a backlink cache object
4878          *
4879          * @return BacklinkCache
4880          */
4881         public function getBacklinkCache() {
4882                 return BacklinkCache::get( $this );
4883         }
4884
4885         /**
4886          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4887          *
4888          * @return Boolean
4889          */
4890         public function canUseNoindex() {
4891                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4892
4893                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4894                         ? $wgContentNamespaces
4895                         : $wgExemptFromUserRobotsControl;
4896
4897                 return !in_array( $this->mNamespace, $bannedNamespaces );
4898
4899         }
4900
4901         /**
4902          * Returns the raw sort key to be used for categories, with the specified
4903          * prefix.  This will be fed to Collation::getSortKey() to get a
4904          * binary sortkey that can be used for actual sorting.
4905          *
4906          * @param string $prefix The prefix to be used, specified using
4907          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4908          *   prefix.
4909          * @return string
4910          */
4911         public function getCategorySortkey( $prefix = '' ) {
4912                 $unprefixed = $this->getText();
4913
4914                 // Anything that uses this hook should only depend
4915                 // on the Title object passed in, and should probably
4916                 // tell the users to run updateCollations.php --force
4917                 // in order to re-sort existing category relations.
4918                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4919                 if ( $prefix !== '' ) {
4920                         # Separate with a line feed, so the unprefixed part is only used as
4921                         # a tiebreaker when two pages have the exact same prefix.
4922                         # In UCA, tab is the only character that can sort above LF
4923                         # so we strip both of them from the original prefix.
4924                         $prefix = strtr( $prefix, "\n\t", '  ' );
4925                         return "$prefix\n$unprefixed";
4926                 }
4927                 return $unprefixed;
4928         }
4929
4930         /**
4931          * Get the language in which the content of this page is written in
4932          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4933          * e.g. $wgLang (such as special pages, which are in the user language).
4934          *
4935          * @since 1.18
4936          * @return Language
4937          */
4938         public function getPageLanguage() {
4939                 global $wgLang, $wgLanguageCode;
4940                 wfProfileIn( __METHOD__ );
4941                 if ( $this->isSpecialPage() ) {
4942                         // special pages are in the user language
4943                         wfProfileOut( __METHOD__ );
4944                         return $wgLang;
4945                 }
4946
4947                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4948                         // Note that this may depend on user settings, so the cache should be only per-request.
4949                         // NOTE: ContentHandler::getPageLanguage() may need to load the content to determine the page language!
4950                         // Checking $wgLanguageCode hasn't changed for the benefit of unit tests.
4951                         $contentHandler = ContentHandler::getForTitle( $this );
4952                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4953                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4954                 } else {
4955                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4956                 }
4957                 wfProfileOut( __METHOD__ );
4958                 return $langObj;
4959         }
4960
4961         /**
4962          * Get the language in which the content of this page is written when
4963          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4964          * e.g. $wgLang (such as special pages, which are in the user language).
4965          *
4966          * @since 1.20
4967          * @return Language
4968          */
4969         public function getPageViewLanguage() {
4970                 global $wgLang;
4971
4972                 if ( $this->isSpecialPage() ) {
4973                         // If the user chooses a variant, the content is actually
4974                         // in a language whose code is the variant code.
4975                         $variant = $wgLang->getPreferredVariant();
4976                         if ( $wgLang->getCode() !== $variant ) {
4977                                 return Language::factory( $variant );
4978                         }
4979
4980                         return $wgLang;
4981                 }
4982
4983                 //NOTE: can't be cached persistently, depends on user settings
4984                 //NOTE: ContentHandler::getPageViewLanguage() may need to load the content to determine the page language!
4985                 $contentHandler = ContentHandler::getForTitle( $this );
4986                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4987                 return $pageLang;
4988         }
4989
4990         /**
4991          * Get a list of rendered edit notices for this page.
4992          *
4993          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4994          * they will already be wrapped in paragraphs.
4995          *
4996          * @since 1.21
4997          * @param int oldid Revision ID that's being edited
4998          * @return Array
4999          */
5000         public function getEditNotices( $oldid = 0 ) {
5001                 $notices = array();
5002
5003                 # Optional notices on a per-namespace and per-page basis
5004                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
5005                 $editnotice_ns_message = wfMessage( $editnotice_ns );
5006                 if ( $editnotice_ns_message->exists() ) {
5007                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
5008                 }
5009                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
5010                         $parts = explode( '/', $this->getDBkey() );
5011                         $editnotice_base = $editnotice_ns;
5012                         while ( count( $parts ) > 0 ) {
5013                                 $editnotice_base .= '-' . array_shift( $parts );
5014                                 $editnotice_base_msg = wfMessage( $editnotice_base );
5015                                 if ( $editnotice_base_msg->exists() ) {
5016                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
5017                                 }
5018                         }
5019                 } else {
5020                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
5021                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
5022                         $editnoticeMsg = wfMessage( $editnoticeText );
5023                         if ( $editnoticeMsg->exists() ) {
5024                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
5025                         }
5026                 }
5027
5028                 wfRunHooks( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
5029                 return $notices;
5030         }
5031 }