includes/Title.php

   1 <?php
   2 /**
   3  * Representation of a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  *
  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 self::getLocalURL for the arguments.
1504          * @see wfExpandUrl
1505          * @param $query
1506          * @param $query2 bool
1507          * @param $proto Protocol type to use in URL
1508          * @return String the URL
1509          */
1510         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1511                 $query = self::fixUrlQueryArgs( $query, $query2 );
1512
1513                 # Hand off all the decisions on urls to getLocalURL
1514                 $url = $this->getLocalURL( $query );
1515
1516                 # Expand the url to make it a full url. Note that getLocalURL has the
1517                 # potential to output full urls for a variety of reasons, so we use
1518                 # wfExpandUrl instead of simply prepending $wgServer
1519                 $url = wfExpandUrl( $url, $proto );
1520
1521                 # Finally, add the fragment.
1522                 $url .= $this->getFragmentForURL();
1523
1524                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1525                 return $url;
1526         }
1527
1528         /**
1529          * Get a URL with no fragment or server name (relative URL) from a Title object.
1530          * If this page is generated with action=render, however,
1531          * $wgServer is prepended to make an absolute URL.
1532          *
1533          * @see self::getFullURL to always get an absolute URL.
1534          * @see self::newFromText to produce a Title object.
1535          *
1536          * @param string|array $query an optional query string,
1537          *   not used for interwiki links. Can be specified as an associative array as well,
1538          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1539          *   Some query patterns will trigger various shorturl path replacements.
1540          * @param $query2 Mixed: An optional secondary query array. This one MUST
1541          *   be an array. If a string is passed it will be interpreted as a deprecated
1542          *   variant argument and urlencoded into a variant= argument.
1543          *   This second query argument will be added to the $query
1544          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1545          *   pair in the first parameter array instead.
1546          *
1547          * @return String of the URL.
1548          */
1549         public function getLocalURL( $query = '', $query2 = false ) {
1550                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1551
1552                 $query = self::fixUrlQueryArgs( $query, $query2 );
1553
1554                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1555                 if ( $interwiki ) {
1556                         $namespace = $this->getNsText();
1557                         if ( $namespace != '' ) {
1558                                 # Can this actually happen? Interwikis shouldn't be parsed.
1559                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1560                                 $namespace .= ':';
1561                         }
1562                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1563                         $url = wfAppendQuery( $url, $query );
1564                 } else {
1565                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1566                         if ( $query == '' ) {
1567                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1568                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1569                         } else {
1570                                 global $wgVariantArticlePath, $wgActionPaths, $wgContLang;
1571                                 $url = false;
1572                                 $matches = array();
1573
1574                                 if ( !empty( $wgActionPaths )
1575                                         && preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches )
1576                                 ) {
1577                                         $action = urldecode( $matches[2] );
1578                                         if ( isset( $wgActionPaths[$action] ) ) {
1579                                                 $query = $matches[1];
1580                                                 if ( isset( $matches[4] ) ) {
1581                                                         $query .= $matches[4];
1582                                                 }
1583                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1584                                                 if ( $query != '' ) {
1585                                                         $url = wfAppendQuery( $url, $query );
1586                                                 }
1587                                         }
1588                                 }
1589
1590                                 if ( $url === false
1591                                         && $wgVariantArticlePath
1592                                         && $wgContLang->getCode() === $this->getPageLanguage()->getCode()
1593                                         && $this->getPageLanguage()->hasVariants()
1594                                         && preg_match( '/^variant=([^&]*)$/', $query, $matches )
1595                                 ) {
1596                                         $variant = urldecode( $matches[1] );
1597                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1598                                                 // Only do the variant replacement if the given variant is a valid
1599                                                 // variant for the page's language.
1600                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1601                                                 $url = str_replace( '$1', $dbkey, $url );
1602                                         }
1603                                 }
1604
1605                                 if ( $url === false ) {
1606                                         if ( $query == '-' ) {
1607                                                 $query = '';
1608                                         }
1609                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1610                                 }
1611                         }
1612
1613                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1614
1615                         // @todo FIXME: This causes breakage in various places when we
1616                         // actually expected a local URL and end up with dupe prefixes.
1617                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1618                                 $url = $wgServer . $url;
1619                         }
1620                 }
1621                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1622                 return $url;
1623         }
1624
1625         /**
1626          * Get a URL that's the simplest URL that will be valid to link, locally,
1627          * to the current Title.  It includes the fragment, but does not include
1628          * the server unless action=render is used (or the link is external).  If
1629          * there's a fragment but the prefixed text is empty, we just return a link
1630          * to the fragment.
1631          *
1632          * The result obviously should not be URL-escaped, but does need to be
1633          * HTML-escaped if it's being output in HTML.
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 for the arguments.
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 self::getLocalURL for the arguments.
1659          * @param $query string
1660          * @param $query2 bool|string
1661          * @return String the URL
1662          * @deprecated since 1.19
1663          */
1664         public function escapeLocalURL( $query = '', $query2 = false ) {
1665                 wfDeprecated( __METHOD__, '1.19' );
1666                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1667         }
1668
1669         /**
1670          * Get an HTML-escaped version of the URL form, suitable for
1671          * using in a link, including the server name and fragment
1672          *
1673          * @see self::getLocalURL for the arguments.
1674          * @return String the URL
1675          * @deprecated since 1.19
1676          */
1677         public function escapeFullURL( $query = '', $query2 = false ) {
1678                 wfDeprecated( __METHOD__, '1.19' );
1679                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1680         }
1681
1682         /**
1683          * Get the URL form for an internal link.
1684          * - Used in various Squid-related code, in case we have a different
1685          * internal hostname for the server from the exposed one.
1686          *
1687          * This uses $wgInternalServer to qualify the path, or $wgServer
1688          * if $wgInternalServer is not set. If the server variable used is
1689          * protocol-relative, the URL will be expanded to http://
1690          *
1691          * @see self::getLocalURL for the arguments.
1692          * @return String the URL
1693          */
1694         public function getInternalURL( $query = '', $query2 = false ) {
1695                 global $wgInternalServer, $wgServer;
1696                 $query = self::fixUrlQueryArgs( $query, $query2 );
1697                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1698                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1699                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1700                 return $url;
1701         }
1702
1703         /**
1704          * Get the URL for a canonical link, for use in things like IRC and
1705          * e-mail notifications. Uses $wgCanonicalServer and the
1706          * GetCanonicalURL hook.
1707          *
1708          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1709          *
1710          * @see self::getLocalURL for the arguments.
1711          * @return string The URL
1712          * @since 1.18
1713          */
1714         public function getCanonicalURL( $query = '', $query2 = false ) {
1715                 $query = self::fixUrlQueryArgs( $query, $query2 );
1716                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1717                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1718                 return $url;
1719         }
1720
1721         /**
1722          * HTML-escaped version of getCanonicalURL()
1723          *
1724          * @see self::getLocalURL for the arguments.
1725          * @since 1.18
1726          * @return string
1727          * @deprecated since 1.19
1728          */
1729         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1730                 wfDeprecated( __METHOD__, '1.19' );
1731                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1732         }
1733
1734         /**
1735          * Get the edit URL for this Title
1736          *
1737          * @return String the URL, or a null string if this is an
1738          *  interwiki link
1739          */
1740         public function getEditURL() {
1741                 if ( $this->isExternal() ) {
1742                         return '';
1743                 }
1744                 $s = $this->getLocalURL( 'action=edit' );
1745
1746                 return $s;
1747         }
1748
1749         /**
1750          * Is $wgUser watching this page?
1751          *
1752          * @deprecated in 1.20; use User::isWatched() instead.
1753          * @return Bool
1754          */
1755         public function userIsWatching() {
1756                 global $wgUser;
1757
1758                 if ( is_null( $this->mWatched ) ) {
1759                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1760                                 $this->mWatched = false;
1761                         } else {
1762                                 $this->mWatched = $wgUser->isWatched( $this );
1763                         }
1764                 }
1765                 return $this->mWatched;
1766         }
1767
1768         /**
1769          * Can $wgUser read this page?
1770          *
1771          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1772          * @return Bool
1773          */
1774         public function userCanRead() {
1775                 wfDeprecated( __METHOD__, '1.19' );
1776                 return $this->userCan( 'read' );
1777         }
1778
1779         /**
1780          * Can $user perform $action on this page?
1781          * This skips potentially expensive cascading permission checks
1782          * as well as avoids expensive error formatting
1783          *
1784          * Suitable for use for nonessential UI controls in common cases, but
1785          * _not_ for functional access control.
1786          *
1787          * May provide false positives, but should never provide a false negative.
1788          *
1789          * @param string $action action that permission needs to be checked for
1790          * @param $user User to check (since 1.19); $wgUser will be used if not
1791          *              provided.
1792          * @return Bool
1793          */
1794         public function quickUserCan( $action, $user = null ) {
1795                 return $this->userCan( $action, $user, false );
1796         }
1797
1798         /**
1799          * Can $user perform $action on this page?
1800          *
1801          * @param string $action action that permission needs to be checked for
1802          * @param $user User to check (since 1.19); $wgUser will be used if not
1803          *   provided.
1804          * @param bool $doExpensiveQueries Set this to false to avoid doing
1805          *   unnecessary queries.
1806          * @return Bool
1807          */
1808         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1809                 if ( !$user instanceof User ) {
1810                         global $wgUser;
1811                         $user = $wgUser;
1812                 }
1813                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1814         }
1815
1816         /**
1817          * Can $user perform $action on this page?
1818          *
1819          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1820          *
1821          * @param string $action action that permission needs to be checked for
1822          * @param $user User to check
1823          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1824          *   queries by skipping checks for cascading protections and user blocks.
1825          * @param array $ignoreErrors of Strings Set this to a list of message keys
1826          *   whose corresponding errors may be ignored.
1827          * @return Array of arguments to wfMessage to explain permissions problems.
1828          */
1829         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1830                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1831
1832                 // Remove the errors being ignored.
1833                 foreach ( $errors as $index => $error ) {
1834                         $error_key = is_array( $error ) ? $error[0] : $error;
1835
1836                         if ( in_array( $error_key, $ignoreErrors ) ) {
1837                                 unset( $errors[$index] );
1838                         }
1839                 }
1840
1841                 return $errors;
1842         }
1843
1844         /**
1845          * Permissions checks that fail most often, and which are easiest to test.
1846          *
1847          * @param string $action the action to check
1848          * @param $user User user to check
1849          * @param array $errors list of current errors
1850          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1851          * @param $short Boolean short circuit on first error
1852          *
1853          * @return Array list of errors
1854          */
1855         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1856                 if ( !wfRunHooks( 'TitleQuickPermissions', array( $this, $user, $action, &$errors, $doExpensiveQueries, $short ) ) ) {
1857                         return $errors;
1858                 }
1859
1860                 if ( $action == 'create' ) {
1861                         if (
1862                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1863                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1864                         ) {
1865                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1866                         }
1867                 } elseif ( $action == 'move' ) {
1868                         if ( !$user->isAllowed( 'move-rootuserpages' )
1869                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1870                                 // Show user page-specific message only if the user can move other pages
1871                                 $errors[] = array( 'cant-move-user-page' );
1872                         }
1873
1874                         // Check if user is allowed to move files if it's a file
1875                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1876                                 $errors[] = array( 'movenotallowedfile' );
1877                         }
1878
1879                         if ( !$user->isAllowed( 'move' ) ) {
1880                                 // User can't move anything
1881                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1882                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1883                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1884                                         // custom message if logged-in users without any special rights can move
1885                                         $errors[] = array( 'movenologintext' );
1886                                 } else {
1887                                         $errors[] = array( 'movenotallowed' );
1888                                 }
1889                         }
1890                 } elseif ( $action == 'move-target' ) {
1891                         if ( !$user->isAllowed( 'move' ) ) {
1892                                 // User can't move anything
1893                                 $errors[] = array( 'movenotallowed' );
1894                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1895                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1896                                 // Show user page-specific message only if the user can move other pages
1897                                 $errors[] = array( 'cant-move-to-user-page' );
1898                         }
1899                 } elseif ( !$user->isAllowed( $action ) ) {
1900                         $errors[] = $this->missingPermissionError( $action, $short );
1901                 }
1902
1903                 return $errors;
1904         }
1905
1906         /**
1907          * Add the resulting error code to the errors array
1908          *
1909          * @param array $errors list of current errors
1910          * @param $result Mixed result of errors
1911          *
1912          * @return Array list of errors
1913          */
1914         private function resultToError( $errors, $result ) {
1915                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1916                         // A single array representing an error
1917                         $errors[] = $result;
1918                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1919                         // A nested array representing multiple errors
1920                         $errors = array_merge( $errors, $result );
1921                 } elseif ( $result !== '' && is_string( $result ) ) {
1922                         // A string representing a message-id
1923                         $errors[] = array( $result );
1924                 } elseif ( $result === false ) {
1925                         // a generic "We don't want them to do that"
1926                         $errors[] = array( 'badaccess-group0' );
1927                 }
1928                 return $errors;
1929         }
1930
1931         /**
1932          * Check various permission hooks
1933          *
1934          * @param string $action the action to check
1935          * @param $user User user to check
1936          * @param array $errors list of current errors
1937          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1938          * @param $short Boolean short circuit on first error
1939          *
1940          * @return Array list of errors
1941          */
1942         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1943                 // Use getUserPermissionsErrors instead
1944                 $result = '';
1945                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1946                         return $result ? array() : array( array( 'badaccess-group0' ) );
1947                 }
1948                 // Check getUserPermissionsErrors hook
1949                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1950                         $errors = $this->resultToError( $errors, $result );
1951                 }
1952                 // Check getUserPermissionsErrorsExpensive hook
1953                 if (
1954                         $doExpensiveQueries
1955                         && !( $short && count( $errors ) > 0 )
1956                         && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
1957                 ) {
1958                         $errors = $this->resultToError( $errors, $result );
1959                 }
1960
1961                 return $errors;
1962         }
1963
1964         /**
1965          * Check permissions on special pages & namespaces
1966          *
1967          * @param string $action the action to check
1968          * @param $user User user to check
1969          * @param array $errors list of current errors
1970          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1971          * @param $short Boolean short circuit on first error
1972          *
1973          * @return Array list of errors
1974          */
1975         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1976                 # Only 'createaccount' can be performed on special pages,
1977                 # which don't actually exist in the DB.
1978                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
1979                         $errors[] = array( 'ns-specialprotected' );
1980                 }
1981
1982                 # Check $wgNamespaceProtection for restricted namespaces
1983                 if ( $this->isNamespaceProtected( $user ) ) {
1984                         $ns = $this->mNamespace == NS_MAIN ?
1985                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
1986                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1987                                 array( 'protectedinterface' ) : array( 'namespaceprotected', $ns );
1988                 }
1989
1990                 return $errors;
1991         }
1992
1993         /**
1994          * Check CSS/JS sub-page permissions
1995          *
1996          * @param string $action the action to check
1997          * @param $user User user to check
1998          * @param array $errors list of current errors
1999          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2000          * @param $short Boolean short circuit on first error
2001          *
2002          * @return Array list of errors
2003          */
2004         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2005                 # Protect css/js subpages of user pages
2006                 # XXX: this might be better using restrictions
2007                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
2008                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' ) ) {
2009                         if ( preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
2010                                 if ( $this->isCssSubpage() && !$user->isAllowedAny( 'editmyusercss', 'editusercss' ) ) {
2011                                         $errors[] = array( 'mycustomcssprotected' );
2012                                 } elseif ( $this->isJsSubpage() && !$user->isAllowedAny( 'editmyuserjs', 'edituserjs' ) ) {
2013                                         $errors[] = array( 'mycustomjsprotected' );
2014                                 }
2015                         } else {
2016                                 if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
2017                                         $errors[] = array( 'customcssprotected' );
2018                                 } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
2019                                         $errors[] = array( 'customjsprotected' );
2020                                 }
2021                         }
2022                 }
2023
2024                 return $errors;
2025         }
2026
2027         /**
2028          * Check against page_restrictions table requirements on this
2029          * page. The user must possess all required rights for this
2030          * action.
2031          *
2032          * @param string $action the action to check
2033          * @param $user User user to check
2034          * @param array $errors list of current errors
2035          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2036          * @param $short Boolean short circuit on first error
2037          *
2038          * @return Array list of errors
2039          */
2040         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2041                 foreach ( $this->getRestrictions( $action ) as $right ) {
2042                         // Backwards compatibility, rewrite sysop -> editprotected
2043                         if ( $right == 'sysop' ) {
2044                                 $right = 'editprotected';
2045                         }
2046                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2047                         if ( $right == 'autoconfirmed' ) {
2048                                 $right = 'editsemiprotected';
2049                         }
2050                         if ( $right == '' ) {
2051                                 continue;
2052                         }
2053                         if ( !$user->isAllowed( $right ) ) {
2054                                 $errors[] = array( 'protectedpagetext', $right );
2055                         } elseif ( $this->mCascadeRestriction && !$user->isAllowed( 'protect' ) ) {
2056                                 $errors[] = array( 'protectedpagetext', 'protect' );
2057                         }
2058                 }
2059
2060                 return $errors;
2061         }
2062
2063         /**
2064          * Check restrictions on cascading pages.
2065          *
2066          * @param string $action the action to check
2067          * @param $user User to check
2068          * @param array $errors list of current errors
2069          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2070          * @param $short Boolean short circuit on first error
2071          *
2072          * @return Array list of errors
2073          */
2074         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2075                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
2076                         # We /could/ use the protection level on the source page, but it's
2077                         # fairly ugly as we have to establish a precedence hierarchy for pages
2078                         # included by multiple cascade-protected pages. So just restrict
2079                         # it to people with 'protect' permission, as they could remove the
2080                         # protection anyway.
2081                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
2082                         # Cascading protection depends on more than this page...
2083                         # Several cascading protected pages may include this page...
2084                         # Check each cascading level
2085                         # This is only for protection restrictions, not for all actions
2086                         if ( isset( $restrictions[$action] ) ) {
2087                                 foreach ( $restrictions[$action] as $right ) {
2088                                         // Backwards compatibility, rewrite sysop -> editprotected
2089                                         if ( $right == 'sysop' ) {
2090                                                 $right = 'editprotected';
2091                                         }
2092                                         // Backwards compatibility, rewrite autoconfirmed -> editsemiprotected
2093                                         if ( $right == 'autoconfirmed' ) {
2094                                                 $right = 'editsemiprotected';
2095                                         }
2096                                         if ( $right != '' && !$user->isAllowedAll( 'protect', $right ) ) {
2097                                                 $pages = '';
2098                                                 foreach ( $cascadingSources as $page ) {
2099                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
2100                                                 }
2101                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
2102                                         }
2103                                 }
2104                         }
2105                 }
2106
2107                 return $errors;
2108         }
2109
2110         /**
2111          * Check action permissions not already checked in checkQuickPermissions
2112          *
2113          * @param string $action the action to check
2114          * @param $user User to check
2115          * @param array $errors list of current errors
2116          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2117          * @param $short Boolean short circuit on first error
2118          *
2119          * @return Array list of errors
2120          */
2121         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2122                 global $wgDeleteRevisionsLimit, $wgLang;
2123
2124                 if ( $action == 'protect' ) {
2125                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
2126                                 // If they can't edit, they shouldn't protect.
2127                                 $errors[] = array( 'protect-cantedit' );
2128                         }
2129                 } elseif ( $action == 'create' ) {
2130                         $title_protection = $this->getTitleProtection();
2131                         if ( $title_protection ) {
2132                                 if ( $title_protection['pt_create_perm'] == 'sysop' ) {
2133                                         $title_protection['pt_create_perm'] = 'editprotected'; // B/C
2134                                 }
2135                                 if ( $title_protection['pt_create_perm'] == 'autoconfirmed' ) {
2136                                         $title_protection['pt_create_perm'] = 'editsemiprotected'; // B/C
2137                                 }
2138                                 if ( $title_protection['pt_create_perm'] == ''
2139                                         || !$user->isAllowed( $title_protection['pt_create_perm'] )
2140                                 ) {
2141                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
2142                                 }
2143                         }
2144                 } elseif ( $action == 'move' ) {
2145                         // Check for immobile pages
2146                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2147                                 // Specific message for this case
2148                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2149                         } elseif ( !$this->isMovable() ) {
2150                                 // Less specific message for rarer cases
2151                                 $errors[] = array( 'immobile-source-page' );
2152                         }
2153                 } elseif ( $action == 'move-target' ) {
2154                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2155                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2156                         } elseif ( !$this->isMovable() ) {
2157                                 $errors[] = array( 'immobile-target-page' );
2158                         }
2159                 } elseif ( $action == 'delete' ) {
2160                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2161                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion()
2162                         ) {
2163                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2164                         }
2165                 }
2166                 return $errors;
2167         }
2168
2169         /**
2170          * Check that the user isn't blocked from editing.
2171          *
2172          * @param string $action the action to check
2173          * @param $user User to check
2174          * @param array $errors list of current errors
2175          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2176          * @param $short Boolean short circuit on first error
2177          *
2178          * @return Array list of errors
2179          */
2180         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2181                 // Account creation blocks handled at userlogin.
2182                 // Unblocking handled in SpecialUnblock
2183                 if ( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2184                         return $errors;
2185                 }
2186
2187                 global $wgEmailConfirmToEdit;
2188
2189                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2190                         $errors[] = array( 'confirmedittext' );
2191                 }
2192
2193                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2194                         // Don't block the user from editing their own talk page unless they've been
2195                         // explicitly blocked from that too.
2196                 } elseif ( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2197                         // @todo FIXME: Pass the relevant context into this function.
2198                         $errors[] = $user->getBlock()->getPermissionsError( RequestContext::getMain() );
2199                 }
2200
2201                 return $errors;
2202         }
2203
2204         /**
2205          * Check that the user is allowed to read this page.
2206          *
2207          * @param string $action the action to check
2208          * @param $user User to check
2209          * @param array $errors list of current errors
2210          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2211          * @param $short Boolean short circuit on first error
2212          *
2213          * @return Array list of errors
2214          */
2215         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2216                 global $wgWhitelistRead, $wgWhitelistReadRegexp;
2217
2218                 $whitelisted = false;
2219                 if ( User::isEveryoneAllowed( 'read' ) ) {
2220                         # Shortcut for public wikis, allows skipping quite a bit of code
2221                         $whitelisted = true;
2222                 } elseif ( $user->isAllowed( 'read' ) ) {
2223                         # If the user is allowed to read pages, he is allowed to read all pages
2224                         $whitelisted = true;
2225                 } elseif ( $this->isSpecial( 'Userlogin' )
2226                         || $this->isSpecial( 'ChangePassword' )
2227                         || $this->isSpecial( 'PasswordReset' )
2228                 ) {
2229                         # Always grant access to the login page.
2230                         # Even anons need to be able to log in.
2231                         $whitelisted = true;
2232                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2233                         # Time to check the whitelist
2234                         # Only do these checks is there's something to check against
2235                         $name = $this->getPrefixedText();
2236                         $dbName = $this->getPrefixedDBkey();
2237
2238                         // Check for explicit whitelisting with and without underscores
2239                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2240                                 $whitelisted = true;
2241                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2242                                 # Old settings might have the title prefixed with
2243                                 # a colon for main-namespace pages
2244                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2245                                         $whitelisted = true;
2246                                 }
2247                         } elseif ( $this->isSpecialPage() ) {
2248                                 # If it's a special page, ditch the subpage bit and check again
2249                                 $name = $this->getDBkey();
2250                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2251                                 if ( $name ) {
2252                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2253                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2254                                                 $whitelisted = true;
2255                                         }
2256                                 }
2257                         }
2258                 }
2259
2260                 if ( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2261                         $name = $this->getPrefixedText();
2262                         // Check for regex whitelisting
2263                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2264                                 if ( preg_match( $listItem, $name ) ) {
2265                                         $whitelisted = true;
2266                                         break;
2267                                 }
2268                         }
2269                 }
2270
2271                 if ( !$whitelisted ) {
2272                         # If the title is not whitelisted, give extensions a chance to do so...
2273                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2274                         if ( !$whitelisted ) {
2275                                 $errors[] = $this->missingPermissionError( $action, $short );
2276                         }
2277                 }
2278
2279                 return $errors;
2280         }
2281
2282         /**
2283          * Get a description array when the user doesn't have the right to perform
2284          * $action (i.e. when User::isAllowed() returns false)
2285          *
2286          * @param string $action the action to check
2287          * @param $short Boolean short circuit on first error
2288          * @return Array list of errors
2289          */
2290         private function missingPermissionError( $action, $short ) {
2291                 // We avoid expensive display logic for quickUserCan's and such
2292                 if ( $short ) {
2293                         return array( 'badaccess-group0' );
2294                 }
2295
2296                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2297                         User::getGroupsWithPermission( $action ) );
2298
2299                 if ( count( $groups ) ) {
2300                         global $wgLang;
2301                         return array(
2302                                 'badaccess-groups',
2303                                 $wgLang->commaList( $groups ),
2304                                 count( $groups )
2305                         );
2306                 } else {
2307                         return array( 'badaccess-group0' );
2308                 }
2309         }
2310
2311         /**
2312          * Can $user perform $action on this page? This is an internal function,
2313          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2314          * checks on wfReadOnly() and blocks)
2315          *
2316          * @param string $action action that permission needs to be checked for
2317          * @param $user User to check
2318          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
2319          * @param bool $short Set this to true to stop after the first permission error.
2320          * @return Array of arrays of the arguments to wfMessage to explain permissions problems.
2321          */
2322         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2323                 wfProfileIn( __METHOD__ );
2324
2325                 # Read has special handling
2326                 if ( $action == 'read' ) {
2327                         $checks = array(
2328                                 'checkPermissionHooks',
2329                                 'checkReadPermissions',
2330                         );
2331                 } else {
2332                         $checks = array(
2333                                 'checkQuickPermissions',
2334                                 'checkPermissionHooks',
2335                                 'checkSpecialsAndNSPermissions',
2336                                 'checkCSSandJSPermissions',
2337                                 'checkPageRestrictions',
2338                                 'checkCascadingSourcesRestrictions',
2339                                 'checkActionPermissions',
2340                                 'checkUserBlock'
2341                         );
2342                 }
2343
2344                 $errors = array();
2345                 while ( count( $checks ) > 0 &&
2346                                 !( $short && count( $errors ) > 0 ) ) {
2347                         $method = array_shift( $checks );
2348                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2349                 }
2350
2351                 wfProfileOut( __METHOD__ );
2352                 return $errors;
2353         }
2354
2355         /**
2356          * Get a filtered list of all restriction types supported by this wiki.
2357          * @param bool $exists True to get all restriction types that apply to
2358          * titles that do exist, False for all restriction types that apply to
2359          * titles that do not exist
2360          * @return array
2361          */
2362         public static function getFilteredRestrictionTypes( $exists = true ) {
2363                 global $wgRestrictionTypes;
2364                 $types = $wgRestrictionTypes;
2365                 if ( $exists ) {
2366                         # Remove the create restriction for existing titles
2367                         $types = array_diff( $types, array( 'create' ) );
2368                 } else {
2369                         # Only the create and upload restrictions apply to non-existing titles
2370                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2371                 }
2372                 return $types;
2373         }
2374
2375         /**
2376          * Returns restriction types for the current Title
2377          *
2378          * @return array applicable restriction types
2379          */
2380         public function getRestrictionTypes() {
2381                 if ( $this->isSpecialPage() ) {
2382                         return array();
2383                 }
2384
2385                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2386
2387                 if ( $this->getNamespace() != NS_FILE ) {
2388                         # Remove the upload restriction for non-file titles
2389                         $types = array_diff( $types, array( 'upload' ) );
2390                 }
2391
2392                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2393
2394                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2395                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2396
2397                 return $types;
2398         }
2399
2400         /**
2401          * Is this title subject to title protection?
2402          * Title protection is the one applied against creation of such title.
2403          *
2404          * @return Mixed An associative array representing any existent title
2405          *   protection, or false if there's none.
2406          */
2407         private function getTitleProtection() {
2408                 // Can't protect pages in special namespaces
2409                 if ( $this->getNamespace() < 0 ) {
2410                         return false;
2411                 }
2412
2413                 // Can't protect pages that exist.
2414                 if ( $this->exists() ) {
2415                         return false;
2416                 }
2417
2418                 if ( !isset( $this->mTitleProtection ) ) {
2419                         $dbr = wfGetDB( DB_SLAVE );
2420                         $res = $dbr->select(
2421                                 'protected_titles',
2422                                 array( 'pt_user', 'pt_reason', 'pt_expiry', 'pt_create_perm' ),
2423                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2424                                 __METHOD__
2425                         );
2426
2427                         // fetchRow returns false if there are no rows.
2428                         $this->mTitleProtection = $dbr->fetchRow( $res );
2429                 }
2430                 return $this->mTitleProtection;
2431         }
2432
2433         /**
2434          * Update the title protection status
2435          *
2436          * @deprecated in 1.19; use WikiPage::doUpdateRestrictions() instead.
2437          * @param $create_perm String Permission required for creation
2438          * @param string $reason Reason for protection
2439          * @param string $expiry Expiry timestamp
2440          * @return boolean true
2441          */
2442         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2443                 wfDeprecated( __METHOD__, '1.19' );
2444
2445                 global $wgUser;
2446
2447                 $limit = array( 'create' => $create_perm );
2448                 $expiry = array( 'create' => $expiry );
2449
2450                 $page = WikiPage::factory( $this );
2451                 $cascade = false;
2452                 $status = $page->doUpdateRestrictions( $limit, $expiry, $cascade, $reason, $wgUser );
2453
2454                 return $status->isOK();
2455         }
2456
2457         /**
2458          * Remove any title protection due to page existing
2459          */
2460         public function deleteTitleProtection() {
2461                 $dbw = wfGetDB( DB_MASTER );
2462
2463                 $dbw->delete(
2464                         'protected_titles',
2465                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2466                         __METHOD__
2467                 );
2468                 $this->mTitleProtection = false;
2469         }
2470
2471         /**
2472          * Is this page "semi-protected" - the *only* protection levels are listed
2473          * in $wgSemiprotectedRestrictionLevels?
2474          *
2475          * @param string $action Action to check (default: edit)
2476          * @return Bool
2477          */
2478         public function isSemiProtected( $action = 'edit' ) {
2479                 global $wgSemiprotectedRestrictionLevels;
2480
2481                 $restrictions = $this->getRestrictions( $action );
2482                 $semi = $wgSemiprotectedRestrictionLevels;
2483                 if ( !$restrictions || !$semi ) {
2484                         // Not protected, or all protection is full protection
2485                         return false;
2486                 }
2487
2488                 // Remap autoconfirmed to editsemiprotected for BC
2489                 foreach ( array_keys( $semi, 'autoconfirmed' ) as $key ) {
2490                         $semi[$key] = 'editsemiprotected';
2491                 }
2492                 foreach ( array_keys( $restrictions, 'autoconfirmed' ) as $key ) {
2493                         $restrictions[$key] = 'editsemiprotected';
2494                 }
2495
2496                 return !array_diff( $restrictions, $semi );
2497         }
2498
2499         /**
2500          * Does the title correspond to a protected article?
2501          *
2502          * @param string $action the action the page is protected from,
2503          * by default checks all actions.
2504          * @return Bool
2505          */
2506         public function isProtected( $action = '' ) {
2507                 global $wgRestrictionLevels;
2508
2509                 $restrictionTypes = $this->getRestrictionTypes();
2510
2511                 # Special pages have inherent protection
2512                 if ( $this->isSpecialPage() ) {
2513                         return true;
2514                 }
2515
2516                 # Check regular protection levels
2517                 foreach ( $restrictionTypes as $type ) {
2518                         if ( $action == $type || $action == '' ) {
2519                                 $r = $this->getRestrictions( $type );
2520                                 foreach ( $wgRestrictionLevels as $level ) {
2521                                         if ( in_array( $level, $r ) && $level != '' ) {
2522                                                 return true;
2523                                         }
2524                                 }
2525                         }
2526                 }
2527
2528                 return false;
2529         }
2530
2531         /**
2532          * Determines if $user is unable to edit this page because it has been protected
2533          * by $wgNamespaceProtection.
2534          *
2535          * @param $user User object to check permissions
2536          * @return Bool
2537          */
2538         public function isNamespaceProtected( User $user ) {
2539                 global $wgNamespaceProtection;
2540
2541                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2542                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2543                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2544                                         return true;
2545                                 }
2546                         }
2547                 }
2548                 return false;
2549         }
2550
2551         /**
2552          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2553          *
2554          * @return Bool If the page is subject to cascading restrictions.
2555          */
2556         public function isCascadeProtected() {
2557                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2558                 return ( $sources > 0 );
2559         }
2560
2561         /**
2562          * Determines whether cascading protection sources have already been loaded from
2563          * the database.
2564          *
2565          * @param bool $getPages True to check if the pages are loaded, or false to check
2566          * if the status is loaded.
2567          * @return bool Whether or not the specified information has been loaded
2568          * @since 1.23
2569          */
2570         public function areCascadeProtectionSourcesLoaded( $getPages = true ) {
2571                 return $getPages ? isset( $this->mCascadeSources ) : isset( $this->mHasCascadingRestrictions );
2572         }
2573
2574         /**
2575          * Cascading protection: Get the source of any cascading restrictions on this page.
2576          *
2577          * @param bool $getPages Whether or not to retrieve the actual pages
2578          *        that the restrictions have come from.
2579          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2580          *     have come, false for none, or true if such restrictions exist, but $getPages
2581          *     was not set.  The restriction array is an array of each type, each of which
2582          *     contains a array of unique groups.
2583          */
2584         public function getCascadeProtectionSources( $getPages = true ) {
2585                 global $wgContLang;
2586                 $pagerestrictions = array();
2587
2588                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2589                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2590                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2591                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2592                 }
2593
2594                 wfProfileIn( __METHOD__ );
2595
2596                 $dbr = wfGetDB( DB_SLAVE );
2597
2598                 if ( $this->getNamespace() == NS_FILE ) {
2599                         $tables = array( 'imagelinks', 'page_restrictions' );
2600                         $where_clauses = array(
2601                                 'il_to' => $this->getDBkey(),
2602                                 'il_from=pr_page',
2603                                 'pr_cascade' => 1
2604                         );
2605                 } else {
2606                         $tables = array( 'templatelinks', 'page_restrictions' );
2607                         $where_clauses = array(
2608                                 'tl_namespace' => $this->getNamespace(),
2609                                 'tl_title' => $this->getDBkey(),
2610                                 'tl_from=pr_page',
2611                                 'pr_cascade' => 1
2612                         );
2613                 }
2614
2615                 if ( $getPages ) {
2616                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2617                                 'pr_expiry', 'pr_type', 'pr_level' );
2618                         $where_clauses[] = 'page_id=pr_page';
2619                         $tables[] = 'page';
2620                 } else {
2621                         $cols = array( 'pr_expiry' );
2622                 }
2623
2624                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2625
2626                 $sources = $getPages ? array() : false;
2627                 $now = wfTimestampNow();
2628                 $purgeExpired = false;
2629
2630                 foreach ( $res as $row ) {
2631                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2632                         if ( $expiry > $now ) {
2633                                 if ( $getPages ) {
2634                                         $page_id = $row->pr_page;
2635                                         $page_ns = $row->page_namespace;
2636                                         $page_title = $row->page_title;
2637                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2638                                         # Add groups needed for each restriction type if its not already there
2639                                         # Make sure this restriction type still exists
2640
2641                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2642                                                 $pagerestrictions[$row->pr_type] = array();
2643                                         }
2644
2645                                         if (
2646                                                 isset( $pagerestrictions[$row->pr_type] )
2647                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2648                                         ) {
2649                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2650                                         }
2651                                 } else {
2652                                         $sources = true;
2653                                 }
2654                         } else {
2655                                 // Trigger lazy purge of expired restrictions from the db
2656                                 $purgeExpired = true;
2657                         }
2658                 }
2659                 if ( $purgeExpired ) {
2660                         Title::purgeExpiredRestrictions();
2661                 }
2662
2663                 if ( $getPages ) {
2664                         $this->mCascadeSources = $sources;
2665                         $this->mCascadingRestrictions = $pagerestrictions;
2666                 } else {
2667                         $this->mHasCascadingRestrictions = $sources;
2668                 }
2669
2670                 wfProfileOut( __METHOD__ );
2671                 return array( $sources, $pagerestrictions );
2672         }
2673
2674         /**
2675          * Accessor for mRestrictionsLoaded
2676          *
2677          * @return bool Whether or not the page's restrictions have already been
2678          * loaded from the database
2679          * @since 1.23
2680          */
2681         public function areRestrictionsLoaded() {
2682                 return $this->mRestrictionsLoaded;
2683         }
2684
2685         /**
2686          * Accessor/initialisation for mRestrictions
2687          *
2688          * @param string $action action that permission needs to be checked for
2689          * @return Array of Strings the array of groups allowed to edit this article
2690          */
2691         public function getRestrictions( $action ) {
2692                 if ( !$this->mRestrictionsLoaded ) {
2693                         $this->loadRestrictions();
2694                 }
2695                 return isset( $this->mRestrictions[$action] )
2696                                 ? $this->mRestrictions[$action]
2697                                 : array();
2698         }
2699
2700         /**
2701          * Accessor/initialisation for mRestrictions
2702          *
2703          * @return Array of Arrays of Strings the first level indexed by
2704          * action, the second level containing the names of the groups
2705          * allowed to perform each action
2706          * @since 1.23
2707          */
2708         public function getAllRestrictions() {
2709                 if ( !$this->mRestrictionsLoaded ) {
2710                         $this->loadRestrictions();
2711                 }
2712                 return $this->mRestrictions;
2713         }
2714
2715         /**
2716          * Get the expiry time for the restriction against a given action
2717          *
2718          * @param $action
2719          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2720          *     or not protected at all, or false if the action is not recognised.
2721          */
2722         public function getRestrictionExpiry( $action ) {
2723                 if ( !$this->mRestrictionsLoaded ) {
2724                         $this->loadRestrictions();
2725                 }
2726                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2727         }
2728
2729         /**
2730          * Returns cascading restrictions for the current article
2731          *
2732          * @return Boolean
2733          */
2734         function areRestrictionsCascading() {
2735                 if ( !$this->mRestrictionsLoaded ) {
2736                         $this->loadRestrictions();
2737                 }
2738
2739                 return $this->mCascadeRestriction;
2740         }
2741
2742         /**
2743          * Loads a string into mRestrictions array
2744          *
2745          * @param $res Resource restrictions as an SQL result.
2746          * @param string $oldFashionedRestrictions comma-separated list of page
2747          *        restrictions from page table (pre 1.10)
2748          */
2749         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2750                 $rows = array();
2751
2752                 foreach ( $res as $row ) {
2753                         $rows[] = $row;
2754                 }
2755
2756                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2757         }
2758
2759         /**
2760          * Compiles list of active page restrictions from both page table (pre 1.10)
2761          * and page_restrictions table for this existing page.
2762          * Public for usage by LiquidThreads.
2763          *
2764          * @param array $rows of db result objects
2765          * @param string $oldFashionedRestrictions comma-separated list of page
2766          *        restrictions from page table (pre 1.10)
2767          */
2768         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2769                 global $wgContLang;
2770                 $dbr = wfGetDB( DB_SLAVE );
2771
2772                 $restrictionTypes = $this->getRestrictionTypes();
2773
2774                 foreach ( $restrictionTypes as $type ) {
2775                         $this->mRestrictions[$type] = array();
2776                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2777                 }
2778
2779                 $this->mCascadeRestriction = false;
2780
2781                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2782
2783                 if ( $oldFashionedRestrictions === null ) {
2784                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2785                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2786                 }
2787
2788                 if ( $oldFashionedRestrictions != '' ) {
2789
2790                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2791                                 $temp = explode( '=', trim( $restrict ) );
2792                                 if ( count( $temp ) == 1 ) {
2793                                         // old old format should be treated as edit/move restriction
2794                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2795                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2796                                 } else {
2797                                         $restriction = trim( $temp[1] );
2798                                         if ( $restriction != '' ) { //some old entries are empty
2799                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2800                                         }
2801                                 }
2802                         }
2803
2804                         $this->mOldRestrictions = true;
2805
2806                 }
2807
2808                 if ( count( $rows ) ) {
2809                         # Current system - load second to make them override.
2810                         $now = wfTimestampNow();
2811                         $purgeExpired = false;
2812
2813                         # Cycle through all the restrictions.
2814                         foreach ( $rows as $row ) {
2815
2816                                 // Don't take care of restrictions types that aren't allowed
2817                                 if ( !in_array( $row->pr_type, $restrictionTypes ) ) {
2818                                         continue;
2819                                 }
2820
2821                                 // This code should be refactored, now that it's being used more generally,
2822                                 // But I don't really see any harm in leaving it in Block for now -werdna
2823                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2824
2825                                 // Only apply the restrictions if they haven't expired!
2826                                 if ( !$expiry || $expiry > $now ) {
2827                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2828                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2829
2830                                         $this->mCascadeRestriction |= $row->pr_cascade;
2831                                 } else {
2832                                         // Trigger a lazy purge of expired restrictions
2833                                         $purgeExpired = true;
2834                                 }
2835                         }
2836
2837                         if ( $purgeExpired ) {
2838                                 Title::purgeExpiredRestrictions();
2839                         }
2840                 }
2841
2842                 $this->mRestrictionsLoaded = true;
2843         }
2844
2845         /**
2846          * Load restrictions from the page_restrictions table
2847          *
2848          * @param string $oldFashionedRestrictions comma-separated list of page
2849          *        restrictions from page table (pre 1.10)
2850          */
2851         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2852                 global $wgContLang;
2853                 if ( !$this->mRestrictionsLoaded ) {
2854                         if ( $this->exists() ) {
2855                                 $dbr = wfGetDB( DB_SLAVE );
2856
2857                                 $res = $dbr->select(
2858                                         'page_restrictions',
2859                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2860                                         array( 'pr_page' => $this->getArticleID() ),
2861                                         __METHOD__
2862                                 );
2863
2864                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2865                         } else {
2866                                 $title_protection = $this->getTitleProtection();
2867
2868                                 if ( $title_protection ) {
2869                                         $now = wfTimestampNow();
2870                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2871
2872                                         if ( !$expiry || $expiry > $now ) {
2873                                                 // Apply the restrictions
2874                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2875                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2876                                         } else { // Get rid of the old restrictions
2877                                                 Title::purgeExpiredRestrictions();
2878                                                 $this->mTitleProtection = false;
2879                                         }
2880                                 } else {
2881                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2882                                 }
2883                                 $this->mRestrictionsLoaded = true;
2884                         }
2885                 }
2886         }
2887
2888         /**
2889          * Flush the protection cache in this object and force reload from the database.
2890          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2891          */
2892         public function flushRestrictions() {
2893                 $this->mRestrictionsLoaded = false;
2894                 $this->mTitleProtection = null;
2895         }
2896
2897         /**
2898          * Purge expired restrictions from the page_restrictions table
2899          */
2900         static function purgeExpiredRestrictions() {
2901                 if ( wfReadOnly() ) {
2902                         return;
2903                 }
2904
2905                 $method = __METHOD__;
2906                 $dbw = wfGetDB( DB_MASTER );
2907                 $dbw->onTransactionIdle( function() use ( $dbw, $method ) {
2908                         $dbw->delete(
2909                                 'page_restrictions',
2910                                 array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2911                                 $method
2912                         );
2913                         $dbw->delete(
2914                                 'protected_titles',
2915                                 array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2916                                 $method
2917                         );
2918                 } );
2919         }
2920
2921         /**
2922          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2923          *
2924          * @return Bool
2925          */
2926         public function hasSubpages() {
2927                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2928                         # Duh
2929                         return false;
2930                 }
2931
2932                 # We dynamically add a member variable for the purpose of this method
2933                 # alone to cache the result.  There's no point in having it hanging
2934                 # around uninitialized in every Title object; therefore we only add it
2935                 # if needed and don't declare it statically.
2936                 if ( !isset( $this->mHasSubpages ) ) {
2937                         $this->mHasSubpages = false;
2938                         $subpages = $this->getSubpages( 1 );
2939                         if ( $subpages instanceof TitleArray ) {
2940                                 $this->mHasSubpages = (bool)$subpages->count();
2941                         }
2942                 }
2943
2944                 return $this->mHasSubpages;
2945         }
2946
2947         /**
2948          * Get all subpages of this page.
2949          *
2950          * @param int $limit maximum number of subpages to fetch; -1 for no limit
2951          * @return mixed TitleArray, or empty array if this page's namespace
2952          *  doesn't allow subpages
2953          */
2954         public function getSubpages( $limit = -1 ) {
2955                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2956                         return array();
2957                 }
2958
2959                 $dbr = wfGetDB( DB_SLAVE );
2960                 $conds['page_namespace'] = $this->getNamespace();
2961                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2962                 $options = array();
2963                 if ( $limit > -1 ) {
2964                         $options['LIMIT'] = $limit;
2965                 }
2966                 $this->mSubpages = TitleArray::newFromResult(
2967                         $dbr->select( 'page',
2968                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2969                                 $conds,
2970                                 __METHOD__,
2971                                 $options
2972                         )
2973                 );
2974                 return $this->mSubpages;
2975         }
2976
2977         /**
2978          * Is there a version of this page in the deletion archive?
2979          *
2980          * @return Int the number of archived revisions
2981          */
2982         public function isDeleted() {
2983                 if ( $this->getNamespace() < 0 ) {
2984                         $n = 0;
2985                 } else {
2986                         $dbr = wfGetDB( DB_SLAVE );
2987
2988                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2989                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2990                                 __METHOD__
2991                         );
2992                         if ( $this->getNamespace() == NS_FILE ) {
2993                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2994                                         array( 'fa_name' => $this->getDBkey() ),
2995                                         __METHOD__
2996                                 );
2997                         }
2998                 }
2999                 return (int)$n;
3000         }
3001
3002         /**
3003          * Is there a version of this page in the deletion archive?
3004          *
3005          * @return Boolean
3006          */
3007         public function isDeletedQuick() {
3008                 if ( $this->getNamespace() < 0 ) {
3009                         return false;
3010                 }
3011                 $dbr = wfGetDB( DB_SLAVE );
3012                 $deleted = (bool)$dbr->selectField( 'archive', '1',
3013                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
3014                         __METHOD__
3015                 );
3016                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
3017                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
3018                                 array( 'fa_name' => $this->getDBkey() ),
3019                                 __METHOD__
3020                         );
3021                 }
3022                 return $deleted;
3023         }
3024
3025         /**
3026          * Get the article ID for this Title from the link cache,
3027          * adding it if necessary
3028          *
3029          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select
3030          *  for update
3031          * @return Int the ID
3032          */
3033         public function getArticleID( $flags = 0 ) {
3034                 if ( $this->getNamespace() < 0 ) {
3035                         $this->mArticleID = 0;
3036                         return $this->mArticleID;
3037                 }
3038                 $linkCache = LinkCache::singleton();
3039                 if ( $flags & self::GAID_FOR_UPDATE ) {
3040                         $oldUpdate = $linkCache->forUpdate( true );
3041                         $linkCache->clearLink( $this );
3042                         $this->mArticleID = $linkCache->addLinkObj( $this );
3043                         $linkCache->forUpdate( $oldUpdate );
3044                 } else {
3045                         if ( -1 == $this->mArticleID ) {
3046                                 $this->mArticleID = $linkCache->addLinkObj( $this );
3047                         }
3048                 }
3049                 return $this->mArticleID;
3050         }
3051
3052         /**
3053          * Is this an article that is a redirect page?
3054          * Uses link cache, adding it if necessary
3055          *
3056          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3057          * @return Bool
3058          */
3059         public function isRedirect( $flags = 0 ) {
3060                 if ( !is_null( $this->mRedirect ) ) {
3061                         return $this->mRedirect;
3062                 }
3063                 # Calling getArticleID() loads the field from cache as needed
3064                 if ( !$this->getArticleID( $flags ) ) {
3065                         $this->mRedirect = false;
3066                         return $this->mRedirect;
3067                 }
3068
3069                 $linkCache = LinkCache::singleton();
3070                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
3071                 if ( $cached === null ) {
3072                         # Trust LinkCache's state over our own
3073                         # LinkCache is telling us that the page doesn't exist, despite there being cached
3074                         # data relating to an existing page in $this->mArticleID. Updaters should clear
3075                         # LinkCache as appropriate, or use $flags = Title::GAID_FOR_UPDATE. If that flag is
3076                         # set, then LinkCache will definitely be up to date here, since getArticleID() forces
3077                         # LinkCache to refresh its data from the master.
3078                         $this->mRedirect = false;
3079                         return $this->mRedirect;
3080                 }
3081
3082                 $this->mRedirect = (bool)$cached;
3083
3084                 return $this->mRedirect;
3085         }
3086
3087         /**
3088          * What is the length of this page?
3089          * Uses link cache, adding it if necessary
3090          *
3091          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3092          * @return Int
3093          */
3094         public function getLength( $flags = 0 ) {
3095                 if ( $this->mLength != -1 ) {
3096                         return $this->mLength;
3097                 }
3098                 # Calling getArticleID() loads the field from cache as needed
3099                 if ( !$this->getArticleID( $flags ) ) {
3100                         $this->mLength = 0;
3101                         return $this->mLength;
3102                 }
3103                 $linkCache = LinkCache::singleton();
3104                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
3105                 if ( $cached === null ) {
3106                         # Trust LinkCache's state over our own, as for isRedirect()
3107                         $this->mLength = 0;
3108                         return $this->mLength;
3109                 }
3110
3111                 $this->mLength = intval( $cached );
3112
3113                 return $this->mLength;
3114         }
3115
3116         /**
3117          * What is the page_latest field for this page?
3118          *
3119          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3120          * @return Int or 0 if the page doesn't exist
3121          */
3122         public function getLatestRevID( $flags = 0 ) {
3123                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3124                         return intval( $this->mLatestID );
3125                 }
3126                 # Calling getArticleID() loads the field from cache as needed
3127                 if ( !$this->getArticleID( $flags ) ) {
3128                         $this->mLatestID = 0;
3129                         return $this->mLatestID;
3130                 }
3131                 $linkCache = LinkCache::singleton();
3132                 $linkCache->addLinkObj( $this );
3133                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3134                 if ( $cached === null ) {
3135                         # Trust LinkCache's state over our own, as for isRedirect()
3136                         $this->mLatestID = 0;
3137                         return $this->mLatestID;
3138                 }
3139
3140                 $this->mLatestID = intval( $cached );
3141
3142                 return $this->mLatestID;
3143         }
3144
3145         /**
3146          * This clears some fields in this object, and clears any associated
3147          * keys in the "bad links" section of the link cache.
3148          *
3149          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3150          * loading of the new page_id. It's also called from
3151          * WikiPage::doDeleteArticleReal()
3152          *
3153          * @param int $newid the new Article ID
3154          */
3155         public function resetArticleID( $newid ) {
3156                 $linkCache = LinkCache::singleton();
3157                 $linkCache->clearLink( $this );
3158
3159                 if ( $newid === false ) {
3160                         $this->mArticleID = -1;
3161                 } else {
3162                         $this->mArticleID = intval( $newid );
3163                 }
3164                 $this->mRestrictionsLoaded = false;
3165                 $this->mRestrictions = array();
3166                 $this->mRedirect = null;
3167                 $this->mLength = -1;
3168                 $this->mLatestID = false;
3169                 $this->mContentModel = false;
3170                 $this->mEstimateRevisions = null;
3171                 $this->mPageLanguage = false;
3172         }
3173
3174         /**
3175          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3176          *
3177          * @param string $text containing title to capitalize
3178          * @param int $ns namespace index, defaults to NS_MAIN
3179          * @return String containing capitalized title
3180          */
3181         public static function capitalize( $text, $ns = NS_MAIN ) {
3182                 global $wgContLang;
3183
3184                 if ( MWNamespace::isCapitalized( $ns ) ) {
3185                         return $wgContLang->ucfirst( $text );
3186                 } else {
3187                         return $text;
3188                 }
3189         }
3190
3191         /**
3192          * Secure and split - main initialisation function for this object
3193          *
3194          * Assumes that mDbkeyform has been set, and is urldecoded
3195          * and uses underscores, but not otherwise munged.  This function
3196          * removes illegal characters, splits off the interwiki and
3197          * namespace prefixes, sets the other forms, and canonicalizes
3198          * everything.
3199          *
3200          * @return Bool true on success
3201          */
3202         private function secureAndSplit() {
3203                 global $wgContLang, $wgLocalInterwikis;
3204
3205                 # Initialisation
3206                 $this->mInterwiki = '';
3207                 $this->mFragment = '';
3208                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3209
3210                 $dbkey = $this->mDbkeyform;
3211
3212                 # Strip Unicode bidi override characters.
3213                 # Sometimes they slip into cut-n-pasted page titles, where the
3214                 # override chars get included in list displays.
3215                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
3216
3217                 # Clean up whitespace
3218                 # Note: use of the /u option on preg_replace here will cause
3219                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
3220                 # conveniently disabling them.
3221                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
3222                 $dbkey = trim( $dbkey, '_' );
3223
3224                 if ( strpos( $dbkey, UTF8_REPLACEMENT ) !== false ) {
3225                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
3226                         return false;
3227                 }
3228
3229                 $this->mDbkeyform = $dbkey;
3230
3231                 # Initial colon indicates main namespace rather than specified default
3232                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
3233                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3234                         $this->mNamespace = NS_MAIN;
3235                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
3236                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
3237                 }
3238
3239                 if ( $dbkey == '' ) {
3240                         return false;
3241                 }
3242
3243                 # Namespace or interwiki prefix
3244                 $firstPass = true;
3245                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
3246                 do {
3247                         $m = array();
3248                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3249                                 $p = $m[1];
3250                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3251                                         # Ordinary namespace
3252                                         $dbkey = $m[2];
3253                                         $this->mNamespace = $ns;
3254                                         # For Talk:X pages, check if X has a "namespace" prefix
3255                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3256                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3257                                                         # Disallow Talk:File:x type titles...
3258                                                         return false;
3259                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3260                                                         # Disallow Talk:Interwiki:x type titles...
3261                                                         return false;
3262                                                 }
3263                                         }
3264                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3265                                         if ( !$firstPass ) {
3266                                                 # Can't make a local interwiki link to an interwiki link.
3267                                                 # That's just crazy!
3268                                                 return false;
3269                                         }
3270
3271                                         # Interwiki link
3272                                         $dbkey = $m[2];
3273                                         $this->mInterwiki = $wgContLang->lc( $p );
3274
3275                                         # Redundant interwiki prefix to the local wiki
3276                                         foreach ( $wgLocalInterwikis as $localIW ) {
3277                                                 if ( 0 == strcasecmp( $this->mInterwiki, $localIW ) ) {
3278                                                         if ( $dbkey == '' ) {
3279                                                                 # Can't have an empty self-link
3280                                                                 return false;
3281                                                         }
3282                                                         $this->mInterwiki = '';
3283                                                         $firstPass = false;
3284                                                         # Do another namespace split...
3285                                                         continue 2;
3286                                                 }
3287                                         }
3288
3289                                         # If there's an initial colon after the interwiki, that also
3290                                         # resets the default namespace
3291                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3292                                                 $this->mNamespace = NS_MAIN;
3293                                                 $dbkey = substr( $dbkey, 1 );
3294                                         }
3295                                 }
3296                                 # If there's no recognized interwiki or namespace,
3297                                 # then let the colon expression be part of the title.
3298                         }
3299                         break;
3300                 } while ( true );
3301
3302                 $fragment = strstr( $dbkey, '#' );
3303                 if ( false !== $fragment ) {
3304                         $this->setFragment( $fragment );
3305                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3306                         # remove whitespace again: prevents "Foo_bar_#"
3307                         # becoming "Foo_bar_"
3308                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3309                 }
3310
3311                 # Reject illegal characters.
3312                 $rxTc = self::getTitleInvalidRegex();
3313                 if ( preg_match( $rxTc, $dbkey ) ) {
3314                         return false;
3315                 }
3316
3317                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3318                 # reachable due to the way web browsers deal with 'relative' URLs.
3319                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3320                 if (
3321                         strpos( $dbkey, '.' ) !== false &&
3322                         (
3323                                 $dbkey === '.' || $dbkey === '..' ||
3324                                 strpos( $dbkey, './' ) === 0 ||
3325                                 strpos( $dbkey, '../' ) === 0 ||
3326                                 strpos( $dbkey, '/./' ) !== false ||
3327                                 strpos( $dbkey, '/../' ) !== false ||
3328                                 substr( $dbkey, -2 ) == '/.' ||
3329                                 substr( $dbkey, -3 ) == '/..'
3330                         )
3331                 ) {
3332                         return false;
3333                 }
3334
3335                 # Magic tilde sequences? Nu-uh!
3336                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3337                         return false;
3338                 }
3339
3340                 # Limit the size of titles to 255 bytes. This is typically the size of the
3341                 # underlying database field. We make an exception for special pages, which
3342                 # don't need to be stored in the database, and may edge over 255 bytes due
3343                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3344                 if (
3345                         ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 )
3346                         || strlen( $dbkey ) > 512
3347                 ) {
3348                         return false;
3349                 }
3350
3351                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3352                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3353                 # other site might be case-sensitive.
3354                 $this->mUserCaseDBKey = $dbkey;
3355                 if ( !$this->isExternal() ) {
3356                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3357                 }
3358
3359                 # Can't make a link to a namespace alone... "empty" local links can only be
3360                 # self-links with a fragment identifier.
3361                 if ( $dbkey == '' && !$this->isExternal() && $this->mNamespace != NS_MAIN ) {
3362                         return false;
3363                 }
3364
3365                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3366                 // IP names are not allowed for accounts, and can only be referring to
3367                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3368                 // there are numerous ways to present the same IP. Having sp:contribs scan
3369                 // them all is silly and having some show the edits and others not is
3370                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3371                 if ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) {
3372                         $dbkey = IP::sanitizeIP( $dbkey );
3373                 }
3374
3375                 // Any remaining initial :s are illegal.
3376                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3377                         return false;
3378                 }
3379
3380                 # Fill fields
3381                 $this->mDbkeyform = $dbkey;
3382                 $this->mUrlform = wfUrlencode( $dbkey );
3383
3384                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3385
3386                 # We already know that some pages won't be in the database!
3387                 if ( $this->isExternal() || $this->mNamespace == NS_SPECIAL ) {
3388                         $this->mArticleID = 0;
3389                 }
3390
3391                 return true;
3392         }
3393
3394         /**
3395          * Get an array of Title objects linking to this Title
3396          * Also stores the IDs in the link cache.
3397          *
3398          * WARNING: do not use this function on arbitrary user-supplied titles!
3399          * On heavily-used templates it will max out the memory.
3400          *
3401          * @param array $options may be FOR UPDATE
3402          * @param string $table table name
3403          * @param string $prefix fields prefix
3404          * @return Array of Title objects linking here
3405          */
3406         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3407                 if ( count( $options ) > 0 ) {
3408                         $db = wfGetDB( DB_MASTER );
3409                 } else {
3410                         $db = wfGetDB( DB_SLAVE );
3411                 }
3412
3413                 $res = $db->select(
3414                         array( 'page', $table ),
3415                         self::getSelectFields(),
3416                         array(
3417                                 "{$prefix}_from=page_id",
3418                                 "{$prefix}_namespace" => $this->getNamespace(),
3419                                 "{$prefix}_title" => $this->getDBkey() ),
3420                         __METHOD__,
3421                         $options
3422                 );
3423
3424                 $retVal = array();
3425                 if ( $res->numRows() ) {
3426                         $linkCache = LinkCache::singleton();
3427                         foreach ( $res as $row ) {
3428                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3429                                 if ( $titleObj ) {
3430                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3431                                         $retVal[] = $titleObj;
3432                                 }
3433                         }
3434                 }
3435                 return $retVal;
3436         }
3437
3438         /**
3439          * Get an array of Title objects using this Title as a template
3440          * Also stores the IDs in the link cache.
3441          *
3442          * WARNING: do not use this function on arbitrary user-supplied titles!
3443          * On heavily-used templates it will max out the memory.
3444          *
3445          * @param array $options may be FOR UPDATE
3446          * @return Array of Title the Title objects linking here
3447          */
3448         public function getTemplateLinksTo( $options = array() ) {
3449                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3450         }
3451
3452         /**
3453          * Get an array of Title objects linked from this Title
3454          * Also stores the IDs in the link cache.
3455          *
3456          * WARNING: do not use this function on arbitrary user-supplied titles!
3457          * On heavily-used templates it will max out the memory.
3458          *
3459          * @param array $options may be FOR UPDATE
3460          * @param string $table table name
3461          * @param string $prefix fields prefix
3462          * @return Array of Title objects linking here
3463          */
3464         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3465                 global $wgContentHandlerUseDB;
3466
3467                 $id = $this->getArticleID();
3468
3469                 # If the page doesn't exist; there can't be any link from this page
3470                 if ( !$id ) {
3471                         return array();
3472                 }
3473
3474                 if ( count( $options ) > 0 ) {
3475                         $db = wfGetDB( DB_MASTER );
3476                 } else {
3477                         $db = wfGetDB( DB_SLAVE );
3478                 }
3479
3480                 $namespaceFiled = "{$prefix}_namespace";
3481                 $titleField = "{$prefix}_title";
3482
3483                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3484                 if ( $wgContentHandlerUseDB ) {
3485                         $fields[] = 'page_content_model';
3486                 }
3487
3488                 $res = $db->select(
3489                         array( $table, 'page' ),
3490                         $fields,
3491                         array( "{$prefix}_from" => $id ),
3492                         __METHOD__,
3493                         $options,
3494                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3495                 );
3496
3497                 $retVal = array();
3498                 if ( $res->numRows() ) {
3499                         $linkCache = LinkCache::singleton();
3500                         foreach ( $res as $row ) {
3501                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3502                                 if ( $titleObj ) {
3503                                         if ( $row->page_id ) {
3504                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3505                                         } else {
3506                                                 $linkCache->addBadLinkObj( $titleObj );
3507                                         }
3508                                         $retVal[] = $titleObj;
3509                                 }
3510                         }
3511                 }
3512                 return $retVal;
3513         }
3514
3515         /**
3516          * Get an array of Title objects used on this Title as a template
3517          * Also stores the IDs in the link cache.
3518          *
3519          * WARNING: do not use this function on arbitrary user-supplied titles!
3520          * On heavily-used templates it will max out the memory.
3521          *
3522          * @param array $options may be FOR UPDATE
3523          * @return Array of Title the Title objects used here
3524          */
3525         public function getTemplateLinksFrom( $options = array() ) {
3526                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3527         }
3528
3529         /**
3530          * Get an array of Title objects referring to non-existent articles linked from this page
3531          *
3532          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3533          * @return Array of Title the Title objects
3534          */
3535         public function getBrokenLinksFrom() {
3536                 if ( $this->getArticleID() == 0 ) {
3537                         # All links from article ID 0 are false positives
3538                         return array();
3539                 }
3540
3541                 $dbr = wfGetDB( DB_SLAVE );
3542                 $res = $dbr->select(
3543                         array( 'page', 'pagelinks' ),
3544                         array( 'pl_namespace', 'pl_title' ),
3545                         array(
3546                                 'pl_from' => $this->getArticleID(),
3547                                 'page_namespace IS NULL'
3548                         ),
3549                         __METHOD__, array(),
3550                         array(
3551                                 'page' => array(
3552                                         'LEFT JOIN',
3553                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3554                                 )
3555                         )
3556                 );
3557
3558                 $retVal = array();
3559                 foreach ( $res as $row ) {
3560                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3561                 }
3562                 return $retVal;
3563         }
3564
3565         /**
3566          * Get a list of URLs to purge from the Squid cache when this
3567          * page changes
3568          *
3569          * @return Array of String the URLs
3570          */
3571         public function getSquidURLs() {
3572                 $urls = array(
3573                         $this->getInternalURL(),
3574                         $this->getInternalURL( 'action=history' )
3575                 );
3576
3577                 $pageLang = $this->getPageLanguage();
3578                 if ( $pageLang->hasVariants() ) {
3579                         $variants = $pageLang->getVariants();
3580                         foreach ( $variants as $vCode ) {
3581                                 $urls[] = $this->getInternalURL( '', $vCode );
3582                         }
3583                 }
3584
3585                 // If we are looking at a css/js user subpage, purge the action=raw.
3586                 if ( $this->isJsSubpage() ) {
3587                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/javascript' );
3588                 } elseif ( $this->isCssSubpage() ) {
3589                         $urls[] = $this->getInternalUrl( 'action=raw&ctype=text/css' );
3590                 }
3591
3592                 wfRunHooks( 'TitleSquidURLs', array( $this, &$urls ) );
3593                 return $urls;
3594         }
3595
3596         /**
3597          * Purge all applicable Squid URLs
3598          */
3599         public function purgeSquid() {
3600                 global $wgUseSquid;
3601                 if ( $wgUseSquid ) {
3602                         $urls = $this->getSquidURLs();
3603                         $u = new SquidUpdate( $urls );
3604                         $u->doUpdate();
3605                 }
3606         }
3607
3608         /**
3609          * Move this page without authentication
3610          *
3611          * @param $nt Title the new page Title
3612          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3613          */
3614         public function moveNoAuth( &$nt ) {
3615                 return $this->moveTo( $nt, false );
3616         }
3617
3618         /**
3619          * Check whether a given move operation would be valid.
3620          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3621          *
3622          * @param $nt Title the new title
3623          * @param bool $auth indicates whether $wgUser's permissions
3624          *  should be checked
3625          * @param string $reason is the log summary of the move, used for spam checking
3626          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3627          */
3628         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3629                 global $wgUser, $wgContentHandlerUseDB;
3630
3631                 $errors = array();
3632                 if ( !$nt ) {
3633                         // Normally we'd add this to $errors, but we'll get
3634                         // lots of syntax errors if $nt is not an object
3635                         return array( array( 'badtitletext' ) );
3636                 }
3637                 if ( $this->equals( $nt ) ) {
3638                         $errors[] = array( 'selfmove' );
3639                 }
3640                 if ( !$this->isMovable() ) {
3641                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3642                 }
3643                 if ( $nt->isExternal() ) {
3644                         $errors[] = array( 'immobile-target-namespace-iw' );
3645                 }
3646                 if ( !$nt->isMovable() ) {
3647                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3648                 }
3649
3650                 $oldid = $this->getArticleID();
3651                 $newid = $nt->getArticleID();
3652
3653                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3654                         $errors[] = array( 'articleexists' );
3655                 }
3656                 if (
3657                         ( $this->getDBkey() == '' ) ||
3658                         ( !$oldid ) ||
3659                         ( $nt->getDBkey() == '' )
3660                 ) {
3661                         $errors[] = array( 'badarticleerror' );
3662                 }
3663
3664                 // Content model checks
3665                 if ( !$wgContentHandlerUseDB &&
3666                                 $this->getContentModel() !== $nt->getContentModel() ) {
3667                         // can't move a page if that would change the page's content model
3668                         $errors[] = array(
3669                                 'bad-target-model',
3670                                 ContentHandler::getLocalizedName( $this->getContentModel() ),
3671                                 ContentHandler::getLocalizedName( $nt->getContentModel() )
3672                         );
3673                 }
3674
3675                 // Image-specific checks
3676                 if ( $this->getNamespace() == NS_FILE ) {
3677                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3678                 }
3679
3680                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3681                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3682                 }
3683
3684                 if ( $auth ) {
3685                         $errors = wfMergeErrorArrays( $errors,
3686                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3687                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3688                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3689                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3690                 }
3691
3692                 $match = EditPage::matchSummarySpamRegex( $reason );
3693                 if ( $match !== false ) {
3694                         // This is kind of lame, won't display nice
3695                         $errors[] = array( 'spamprotectiontext' );
3696                 }
3697
3698                 $err = null;
3699                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3700                         $errors[] = array( 'hookaborted', $err );
3701                 }
3702
3703                 # The move is allowed only if (1) the target doesn't exist, or
3704                 # (2) the target is a redirect to the source, and has no history
3705                 # (so we can undo bad moves right after they're done).
3706
3707                 if ( 0 != $newid ) { # Target exists; check for validity
3708                         if ( !$this->isValidMoveTarget( $nt ) ) {
3709                                 $errors[] = array( 'articleexists' );
3710                         }
3711                 } else {
3712                         $tp = $nt->getTitleProtection();
3713                         $right = $tp['pt_create_perm'];
3714                         if ( $right == 'sysop' ) {
3715                                 $right = 'editprotected'; // B/C
3716                         }
3717                         if ( $right == 'autoconfirmed' ) {
3718                                 $right = 'editsemiprotected'; // B/C
3719                         }
3720                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3721                                 $errors[] = array( 'cantmove-titleprotected' );
3722                         }
3723                 }
3724                 if ( empty( $errors ) ) {
3725                         return true;
3726                 }
3727                 return $errors;
3728         }
3729
3730         /**
3731          * Check if the requested move target is a valid file move target
3732          * @param Title $nt Target title
3733          * @return array List of errors
3734          */
3735         protected function validateFileMoveOperation( $nt ) {
3736                 global $wgUser;
3737
3738                 $errors = array();
3739
3740                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3741
3742                 $file = wfLocalFile( $this );
3743                 if ( $file->exists() ) {
3744                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3745                                 $errors[] = array( 'imageinvalidfilename' );
3746                         }
3747                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3748                                 $errors[] = array( 'imagetypemismatch' );
3749                         }
3750                 }
3751
3752                 if ( $nt->getNamespace() != NS_FILE ) {
3753                         $errors[] = array( 'imagenocrossnamespace' );
3754                         // From here we want to do checks on a file object, so if we can't
3755                         // create one, we must return.
3756                         return $errors;
3757                 }
3758
3759                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3760
3761                 $destFile = wfLocalFile( $nt );
3762                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3763                         $errors[] = array( 'file-exists-sharedrepo' );
3764                 }
3765
3766                 return $errors;
3767         }
3768
3769         /**
3770          * Move a title to a new location
3771          *
3772          * @param $nt Title the new title
3773          * @param bool $auth indicates whether $wgUser's permissions
3774          *  should be checked
3775          * @param string $reason the reason for the move
3776          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3777          *  Ignored if the user doesn't have the suppressredirect right.
3778          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3779          */
3780         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3781                 global $wgUser;
3782                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3783                 if ( is_array( $err ) ) {
3784                         // Auto-block user's IP if the account was "hard" blocked
3785                         $wgUser->spreadAnyEditBlock();
3786                         return $err;
3787                 }
3788                 // Check suppressredirect permission
3789                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3790                         $createRedirect = true;
3791                 }
3792
3793                 wfRunHooks( 'TitleMove', array( $this, $nt, $wgUser ) );
3794
3795                 // If it is a file, move it first.
3796                 // It is done before all other moving stuff is done because it's hard to revert.
3797                 $dbw = wfGetDB( DB_MASTER );
3798                 if ( $this->getNamespace() == NS_FILE ) {
3799                         $file = wfLocalFile( $this );
3800                         if ( $file->exists() ) {
3801                                 $status = $file->move( $nt );
3802                                 if ( !$status->isOk() ) {
3803                                         return $status->getErrorsArray();
3804                                 }
3805                         }
3806                         // Clear RepoGroup process cache
3807                         RepoGroup::singleton()->clearCache( $this );
3808                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3809                 }
3810
3811                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3812                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3813                 $protected = $this->isProtected();
3814
3815                 // Do the actual move
3816                 $this->moveToInternal( $nt, $reason, $createRedirect );
3817
3818                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3819                 // cl_timestamp, which may disturb time-based lists on some sites.
3820                 $prefixes = $dbw->select(
3821                         'categorylinks',
3822                         array( 'cl_sortkey_prefix', 'cl_to' ),
3823                         array( 'cl_from' => $pageid ),
3824                         __METHOD__
3825                 );
3826                 foreach ( $prefixes as $prefixRow ) {
3827                         $prefix = $prefixRow->cl_sortkey_prefix;
3828                         $catTo = $prefixRow->cl_to;
3829                         $dbw->update( 'categorylinks',
3830                                 array(
3831                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3832                                                 $nt->getCategorySortkey( $prefix ) ),
3833                                         'cl_timestamp=cl_timestamp' ),
3834                                 array(
3835                                         'cl_from' => $pageid,
3836                                         'cl_to' => $catTo ),
3837                                 __METHOD__
3838                         );
3839                 }
3840
3841                 $redirid = $this->getArticleID();
3842
3843                 if ( $protected ) {
3844                         # Protect the redirect title as the title used to be...
3845                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3846                                 array(
3847                                         'pr_page' => $redirid,
3848                                         'pr_type' => 'pr_type',
3849                                         'pr_level' => 'pr_level',
3850                                         'pr_cascade' => 'pr_cascade',
3851                                         'pr_user' => 'pr_user',
3852                                         'pr_expiry' => 'pr_expiry'
3853                                 ),
3854                                 array( 'pr_page' => $pageid ),
3855                                 __METHOD__,
3856                                 array( 'IGNORE' )
3857                         );
3858                         # Update the protection log
3859                         $log = new LogPage( 'protect' );
3860                         $comment = wfMessage(
3861                                 'prot_1movedto2',
3862                                 $this->getPrefixedText(),
3863                                 $nt->getPrefixedText()
3864                         )->inContentLanguage()->text();
3865                         if ( $reason ) {
3866                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3867                         }
3868                         // @todo FIXME: $params?
3869                         $logId = $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ), $wgUser );
3870
3871                         // reread inserted pr_ids for log relation
3872                         $insertedPrIds = $dbw->select(
3873                                 'page_restrictions',
3874                                 'pr_id',
3875                                 array( 'pr_page' => $redirid ),
3876                                 __METHOD__
3877                         );
3878                         $logRelationsValues = array();
3879                         foreach ( $insertedPrIds as $prid ) {
3880                                 $logRelationsValues[] = $prid->pr_id;
3881                         }
3882                         $log->addRelations( 'pr_id', $logRelationsValues, $logId );
3883                 }
3884
3885                 # Update watchlists
3886                 $oldnamespace = MWNamespace::getSubject( $this->getNamespace() );
3887                 $newnamespace = MWNamespace::getSubject( $nt->getNamespace() );
3888                 $oldtitle = $this->getDBkey();
3889                 $newtitle = $nt->getDBkey();
3890
3891                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3892                         WatchedItem::duplicateEntries( $this, $nt );
3893                 }
3894
3895                 $dbw->commit( __METHOD__ );
3896
3897                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid, $reason ) );
3898                 return true;
3899         }
3900
3901         /**
3902          * Move page to a title which is either a redirect to the
3903          * source page or nonexistent
3904          *
3905          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3906          * @param string $reason The reason for the move
3907          * @param bool $createRedirect Whether to leave a redirect at the old title. Does not check
3908          *   if the user has the suppressredirect right
3909          * @throws MWException
3910          */
3911         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3912                 global $wgUser, $wgContLang;
3913
3914                 if ( $nt->exists() ) {
3915                         $moveOverRedirect = true;
3916                         $logType = 'move_redir';
3917                 } else {
3918                         $moveOverRedirect = false;
3919                         $logType = 'move';
3920                 }
3921
3922                 if ( $createRedirect ) {
3923                         $contentHandler = ContentHandler::getForTitle( $this );
3924                         $redirectContent = $contentHandler->makeRedirectContent( $nt,
3925                                 wfMessage( 'move-redirect-text' )->inContentLanguage()->plain() );
3926
3927                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3928                 } else {
3929                         $redirectContent = null;
3930                 }
3931
3932                 $logEntry = new ManualLogEntry( 'move', $logType );
3933                 $logEntry->setPerformer( $wgUser );
3934                 $logEntry->setTarget( $this );
3935                 $logEntry->setComment( $reason );
3936                 $logEntry->setParameters( array(
3937                         '4::target' => $nt->getPrefixedText(),
3938                         '5::noredir' => $redirectContent ? '0': '1',
3939                 ) );
3940
3941                 $formatter = LogFormatter::newFromEntry( $logEntry );
3942                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3943                 $comment = $formatter->getPlainActionText();
3944                 if ( $reason ) {
3945                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3946                 }
3947                 # Truncate for whole multibyte characters.
3948                 $comment = $wgContLang->truncate( $comment, 255 );
3949
3950                 $oldid = $this->getArticleID();
3951
3952                 $dbw = wfGetDB( DB_MASTER );
3953
3954                 $newpage = WikiPage::factory( $nt );
3955
3956                 if ( $moveOverRedirect ) {
3957                         $newid = $nt->getArticleID();
3958                         $newcontent = $newpage->getContent();
3959
3960                         # Delete the old redirect. We don't save it to history since
3961                         # by definition if we've got here it's rather uninteresting.
3962                         # We have to remove it so that the next step doesn't trigger
3963                         # a conflict on the unique namespace+title index...
3964                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3965
3966                         $newpage->doDeleteUpdates( $newid, $newcontent );
3967                 }
3968
3969                 # Save a null revision in the page's history notifying of the move
3970                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3971                 if ( !is_object( $nullRevision ) ) {
3972                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3973                 }
3974
3975                 $nullRevision->insertOn( $dbw );
3976
3977                 # Change the name of the target page:
3978                 $dbw->update( 'page',
3979                         /* SET */ array(
3980                                 'page_namespace' => $nt->getNamespace(),
3981                                 'page_title' => $nt->getDBkey(),
3982                         ),
3983                         /* WHERE */ array( 'page_id' => $oldid ),
3984                         __METHOD__
3985                 );
3986
3987                 // clean up the old title before reset article id - bug 45348
3988                 if ( !$redirectContent ) {
3989                         WikiPage::onArticleDelete( $this );
3990                 }
3991
3992                 $this->resetArticleID( 0 ); // 0 == non existing
3993                 $nt->resetArticleID( $oldid );
3994                 $newpage->loadPageData( WikiPage::READ_LOCKING ); // bug 46397
3995
3996                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3997
3998                 wfRunHooks( 'NewRevisionFromEditComplete',
3999                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
4000
4001                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
4002
4003                 if ( !$moveOverRedirect ) {
4004                         WikiPage::onArticleCreate( $nt );
4005                 }
4006
4007                 # Recreate the redirect, this time in the other direction.
4008                 if ( $redirectContent ) {
4009                         $redirectArticle = WikiPage::factory( $this );
4010                         $redirectArticle->loadFromRow( false, WikiPage::READ_LOCKING ); // bug 46397
4011                         $newid = $redirectArticle->insertOn( $dbw );
4012                         if ( $newid ) { // sanity
4013                                 $this->resetArticleID( $newid );
4014                                 $redirectRevision = new Revision( array(
4015                                         'title' => $this, // for determining the default content model
4016                                         'page' => $newid,
4017                                         'comment' => $comment,
4018                                         'content' => $redirectContent ) );
4019                                 $redirectRevision->insertOn( $dbw );
4020                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
4021
4022                                 wfRunHooks( 'NewRevisionFromEditComplete',
4023                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
4024
4025                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
4026                         }
4027                 }
4028
4029                 # Log the move
4030                 $logid = $logEntry->insert();
4031                 $logEntry->publish( $logid );
4032         }
4033
4034         /**
4035          * Move this page's subpages to be subpages of $nt
4036          *
4037          * @param $nt Title Move target
4038          * @param bool $auth Whether $wgUser's permissions should be checked
4039          * @param string $reason The reason for the move
4040          * @param bool $createRedirect Whether to create redirects from the old subpages to
4041          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
4042          * @return mixed array with old page titles as keys, and strings (new page titles) or
4043          *     arrays (errors) as values, or an error array with numeric indices if no pages
4044          *     were moved
4045          */
4046         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
4047                 global $wgMaximumMovedPages;
4048                 // Check permissions
4049                 if ( !$this->userCan( 'move-subpages' ) ) {
4050                         return array( 'cant-move-subpages' );
4051                 }
4052                 // Do the source and target namespaces support subpages?
4053                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4054                         return array( 'namespace-nosubpages',
4055                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
4056                 }
4057                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
4058                         return array( 'namespace-nosubpages',
4059                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
4060                 }
4061
4062                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
4063                 $retval = array();
4064                 $count = 0;
4065                 foreach ( $subpages as $oldSubpage ) {
4066                         $count++;
4067                         if ( $count > $wgMaximumMovedPages ) {
4068                                 $retval[$oldSubpage->getPrefixedText()] =
4069                                                 array( 'movepage-max-pages',
4070                                                         $wgMaximumMovedPages );
4071                                 break;
4072                         }
4073
4074                         // We don't know whether this function was called before
4075                         // or after moving the root page, so check both
4076                         // $this and $nt
4077                         if ( $oldSubpage->getArticleID() == $this->getArticleID()
4078                                 || $oldSubpage->getArticleID() == $nt->getArticleID()
4079                         ) {
4080                                 // When moving a page to a subpage of itself,
4081                                 // don't move it twice
4082                                 continue;
4083                         }
4084                         $newPageName = preg_replace(
4085                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
4086                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
4087                                         $oldSubpage->getDBkey() );
4088                         if ( $oldSubpage->isTalkPage() ) {
4089                                 $newNs = $nt->getTalkPage()->getNamespace();
4090                         } else {
4091                                 $newNs = $nt->getSubjectPage()->getNamespace();
4092                         }
4093                         # Bug 14385: we need makeTitleSafe because the new page names may
4094                         # be longer than 255 characters.
4095                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
4096
4097                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
4098                         if ( $success === true ) {
4099                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
4100                         } else {
4101                                 $retval[$oldSubpage->getPrefixedText()] = $success;
4102                         }
4103                 }
4104                 return $retval;
4105         }
4106
4107         /**
4108          * Checks if this page is just a one-rev redirect.
4109          * Adds lock, so don't use just for light purposes.
4110          *
4111          * @return Bool
4112          */
4113         public function isSingleRevRedirect() {
4114                 global $wgContentHandlerUseDB;
4115
4116                 $dbw = wfGetDB( DB_MASTER );
4117
4118                 # Is it a redirect?
4119                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
4120                 if ( $wgContentHandlerUseDB ) {
4121                         $fields[] = 'page_content_model';
4122                 }
4123
4124                 $row = $dbw->selectRow( 'page',
4125                         $fields,
4126                         $this->pageCond(),
4127                         __METHOD__,
4128                         array( 'FOR UPDATE' )
4129                 );
4130                 # Cache some fields we may want
4131                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
4132                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
4133                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
4134                 $this->mContentModel = $row && isset( $row->page_content_model ) ? strval( $row->page_content_model ) : false;
4135                 if ( !$this->mRedirect ) {
4136                         return false;
4137                 }
4138                 # Does the article have a history?
4139                 $row = $dbw->selectField( array( 'page', 'revision' ),
4140                         'rev_id',
4141                         array( 'page_namespace' => $this->getNamespace(),
4142                                 'page_title' => $this->getDBkey(),
4143                                 'page_id=rev_page',
4144                                 'page_latest != rev_id'
4145                         ),
4146                         __METHOD__,
4147                         array( 'FOR UPDATE' )
4148                 );
4149                 # Return true if there was no history
4150                 return ( $row === false );
4151         }
4152
4153         /**
4154          * Checks if $this can be moved to a given Title
4155          * - Selects for update, so don't call it unless you mean business
4156          *
4157          * @param $nt Title the new title to check
4158          * @return Bool
4159          */
4160         public function isValidMoveTarget( $nt ) {
4161                 # Is it an existing file?
4162                 if ( $nt->getNamespace() == NS_FILE ) {
4163                         $file = wfLocalFile( $nt );
4164                         if ( $file->exists() ) {
4165                                 wfDebug( __METHOD__ . ": file exists\n" );
4166                                 return false;
4167                         }
4168                 }
4169                 # Is it a redirect with no history?
4170                 if ( !$nt->isSingleRevRedirect() ) {
4171                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
4172                         return false;
4173                 }
4174                 # Get the article text
4175                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
4176                 if ( !is_object( $rev ) ) {
4177                         return false;
4178                 }
4179                 $content = $rev->getContent();
4180                 # Does the redirect point to the source?
4181                 # Or is it a broken self-redirect, usually caused by namespace collisions?
4182                 $redirTitle = $content ? $content->getRedirectTarget() : null;
4183
4184                 if ( $redirTitle ) {
4185                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
4186                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
4187                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
4188                                 return false;
4189                         } else {
4190                                 return true;
4191                         }
4192                 } else {
4193                         # Fail safe (not a redirect after all. strange.)
4194                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
4195                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
4196                         return false;
4197                 }
4198         }
4199
4200         /**
4201          * Get categories to which this Title belongs and return an array of
4202          * categories' names.
4203          *
4204          * @return Array of parents in the form:
4205          *        $parent => $currentarticle
4206          */
4207         public function getParentCategories() {
4208                 global $wgContLang;
4209
4210                 $data = array();
4211
4212                 $titleKey = $this->getArticleID();
4213
4214                 if ( $titleKey === 0 ) {
4215                         return $data;
4216                 }
4217
4218                 $dbr = wfGetDB( DB_SLAVE );
4219
4220                 $res = $dbr->select(
4221                         'categorylinks',
4222                         'cl_to',
4223                         array( 'cl_from' => $titleKey ),
4224                         __METHOD__
4225                 );
4226
4227                 if ( $res->numRows() > 0 ) {
4228                         foreach ( $res as $row ) {
4229                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
4230                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4231                         }
4232                 }
4233                 return $data;
4234         }
4235
4236         /**
4237          * Get a tree of parent categories
4238          *
4239          * @param array $children with the children in the keys, to check for circular refs
4240          * @return Array Tree of parent categories
4241          */
4242         public function getParentCategoryTree( $children = array() ) {
4243                 $stack = array();
4244                 $parents = $this->getParentCategories();
4245
4246                 if ( $parents ) {
4247                         foreach ( $parents as $parent => $current ) {
4248                                 if ( array_key_exists( $parent, $children ) ) {
4249                                         # Circular reference
4250                                         $stack[$parent] = array();
4251                                 } else {
4252                                         $nt = Title::newFromText( $parent );
4253                                         if ( $nt ) {
4254                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4255                                         }
4256                                 }
4257                         }
4258                 }
4259
4260                 return $stack;
4261         }
4262
4263         /**
4264          * Get an associative array for selecting this title from
4265          * the "page" table
4266          *
4267          * @return Array suitable for the $where parameter of DB::select()
4268          */
4269         public function pageCond() {
4270                 if ( $this->mArticleID > 0 ) {
4271                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4272                         return array( 'page_id' => $this->mArticleID );
4273                 } else {
4274                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4275                 }
4276         }
4277
4278         /**
4279          * Get the revision ID of the previous revision
4280          *
4281          * @param int $revId Revision ID. Get the revision that was before this one.
4282          * @param int $flags Title::GAID_FOR_UPDATE
4283          * @return Int|Bool Old revision ID, or FALSE if none exists
4284          */
4285         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4286                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4287                 $revId = $db->selectField( 'revision', 'rev_id',
4288                         array(
4289                                 'rev_page' => $this->getArticleID( $flags ),
4290                                 'rev_id < ' . intval( $revId )
4291                         ),
4292                         __METHOD__,
4293                         array( 'ORDER BY' => 'rev_id DESC' )
4294                 );
4295
4296                 if ( $revId === false ) {
4297                         return false;
4298                 } else {
4299                         return intval( $revId );
4300                 }
4301         }
4302
4303         /**
4304          * Get the revision ID of the next revision
4305          *
4306          * @param int $revId Revision ID. Get the revision that was after this one.
4307          * @param int $flags Title::GAID_FOR_UPDATE
4308          * @return Int|Bool Next revision ID, or FALSE if none exists
4309          */
4310         public function getNextRevisionID( $revId, $flags = 0 ) {
4311                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4312                 $revId = $db->selectField( 'revision', 'rev_id',
4313                         array(
4314                                 'rev_page' => $this->getArticleID( $flags ),
4315                                 'rev_id > ' . intval( $revId )
4316                         ),
4317                         __METHOD__,
4318                         array( 'ORDER BY' => 'rev_id' )
4319                 );
4320
4321                 if ( $revId === false ) {
4322                         return false;
4323                 } else {
4324                         return intval( $revId );
4325                 }
4326         }
4327
4328         /**
4329          * Get the first revision of the page
4330          *
4331          * @param int $flags Title::GAID_FOR_UPDATE
4332          * @return Revision|Null if page doesn't exist
4333          */
4334         public function getFirstRevision( $flags = 0 ) {
4335                 $pageId = $this->getArticleID( $flags );
4336                 if ( $pageId ) {
4337                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4338                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4339                                 array( 'rev_page' => $pageId ),
4340                                 __METHOD__,
4341                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4342                         );
4343                         if ( $row ) {
4344                                 return new Revision( $row );
4345                         }
4346                 }
4347                 return null;
4348         }
4349
4350         /**
4351          * Get the oldest revision timestamp of this page
4352          *
4353          * @param int $flags Title::GAID_FOR_UPDATE
4354          * @return String: MW timestamp
4355          */
4356         public function getEarliestRevTime( $flags = 0 ) {
4357                 $rev = $this->getFirstRevision( $flags );
4358                 return $rev ? $rev->getTimestamp() : null;
4359         }
4360
4361         /**
4362          * Check if this is a new page
4363          *
4364          * @return bool
4365          */
4366         public function isNewPage() {
4367                 $dbr = wfGetDB( DB_SLAVE );
4368                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4369         }
4370
4371         /**
4372          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4373          *
4374          * @return bool
4375          */
4376         public function isBigDeletion() {
4377                 global $wgDeleteRevisionsLimit;
4378
4379                 if ( !$wgDeleteRevisionsLimit ) {
4380                         return false;
4381                 }
4382
4383                 $revCount = $this->estimateRevisionCount();
4384                 return $revCount > $wgDeleteRevisionsLimit;
4385         }
4386
4387         /**
4388          * Get the  approximate revision count of this page.
4389          *
4390          * @return int
4391          */
4392         public function estimateRevisionCount() {
4393                 if ( !$this->exists() ) {
4394                         return 0;
4395                 }
4396
4397                 if ( $this->mEstimateRevisions === null ) {
4398                         $dbr = wfGetDB( DB_SLAVE );
4399                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4400                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4401                 }
4402
4403                 return $this->mEstimateRevisions;
4404         }
4405
4406         /**
4407          * Get the number of revisions between the given revision.
4408          * Used for diffs and other things that really need it.
4409          *
4410          * @param int|Revision $old Old revision or rev ID (first before range)
4411          * @param int|Revision $new New revision or rev ID (first after range)
4412          * @return Int Number of revisions between these revisions.
4413          */
4414         public function countRevisionsBetween( $old, $new ) {
4415                 if ( !( $old instanceof Revision ) ) {
4416                         $old = Revision::newFromTitle( $this, (int)$old );
4417                 }
4418                 if ( !( $new instanceof Revision ) ) {
4419                         $new = Revision::newFromTitle( $this, (int)$new );
4420                 }
4421                 if ( !$old || !$new ) {
4422                         return 0; // nothing to compare
4423                 }
4424                 $dbr = wfGetDB( DB_SLAVE );
4425                 return (int)$dbr->selectField( 'revision', 'count(*)',
4426                         array(
4427                                 'rev_page' => $this->getArticleID(),
4428                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4429                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4430                         ),
4431                         __METHOD__
4432                 );
4433         }
4434
4435         /**
4436          * Get the authors between the given revisions or revision IDs.
4437          * Used for diffs and other things that really need it.
4438          *
4439          * @since 1.23
4440          *
4441          * @param int|Revision $old Old revision or rev ID (first before range by default)
4442          * @param int|Revision $new New revision or rev ID (first after range by default)
4443          * @param int $limit Maximum number of authors
4444          * @param string|array $options (Optional): Single option, or an array of options:
4445          *     'include_old' Include $old in the range; $new is excluded.
4446          *     'include_new' Include $new in the range; $old is excluded.
4447          *     'include_both' Include both $old and $new in the range.
4448          *     Unknown option values are ignored.
4449          * @return array|null Names of revision authors in the range; null if not both revisions exist
4450          */
4451         public function getAuthorsBetween( $old, $new, $limit, $options = array() ) {
4452                 if ( !( $old instanceof Revision ) ) {
4453                         $old = Revision::newFromTitle( $this, (int)$old );
4454                 }
4455                 if ( !( $new instanceof Revision ) ) {
4456                         $new = Revision::newFromTitle( $this, (int)$new );
4457                 }
4458                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4459                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4460                 // in the sanity check below?
4461                 if ( !$old || !$new ) {
4462                         return null; // nothing to compare
4463                 }
4464                 $authors = array();
4465                 $old_cmp = '>';
4466                 $new_cmp = '<';
4467                 $options = (array)$options;
4468                 if ( in_array( 'include_old', $options ) ) {
4469                         $old_cmp = '>=';
4470                 }
4471                 if ( in_array( 'include_new', $options ) ) {
4472                         $new_cmp = '<=';
4473                 }
4474                 if ( in_array( 'include_both', $options ) ) {
4475                         $old_cmp = '>=';
4476                         $new_cmp = '<=';
4477                 }
4478                 // No DB query needed if $old and $new are the same or successive revisions:
4479                 if ( $old->getId() === $new->getId() ) {
4480                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? array() : array( $old->getRawUserText() );
4481                 } elseif ( $old->getId() === $new->getParentId() ) {
4482                         if ( $old_cmp === '>=' && $new_cmp === '<=' ) {
4483                                 $authors[] = $old->getRawUserText();
4484                                 if ( $old->getRawUserText() != $new->getRawUserText() ) {
4485                                         $authors[] = $new->getRawUserText();
4486                                 }
4487                         } elseif ( $old_cmp === '>=' ) {
4488                                 $authors[] = $old->getRawUserText();
4489                         } elseif ( $new_cmp === '<=' ) {
4490                                 $authors[] = $new->getRawUserText();
4491                         }
4492                         return $authors;
4493                 }
4494                 $dbr = wfGetDB( DB_SLAVE );
4495                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4496                         array(
4497                                 'rev_page' => $this->getArticleID(),
4498                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4499                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4500                         ), __METHOD__,
4501                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4502                 );
4503                 foreach ( $res as $row ) {
4504                         $authors[] = $row->rev_user_text;
4505                 }
4506                 return $authors;
4507         }
4508
4509         /**
4510          * Get the number of authors between the given revisions or revision IDs.
4511          * Used for diffs and other things that really need it.
4512          *
4513          * @param int|Revision $old Old revision or rev ID (first before range by default)
4514          * @param int|Revision $new New revision or rev ID (first after range by default)
4515          * @param int $limit Maximum number of authors
4516          * @param string|array $options (Optional): Single option, or an array of options:
4517          *     'include_old' Include $old in the range; $new is excluded.
4518          *     'include_new' Include $new in the range; $old is excluded.
4519          *     'include_both' Include both $old and $new in the range.
4520          *     Unknown option values are ignored.
4521          * @return int Number of revision authors in the range; zero if not both revisions exist
4522          */
4523         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4524                 $authors = $this->getAuthorsBetween( $old, $new, $limit, $options );
4525                 return $authors ? count( $authors ) : 0;
4526         }
4527
4528         /**
4529          * Compare with another title.
4530          *
4531          * @param $title Title
4532          * @return Bool
4533          */
4534         public function equals( Title $title ) {
4535                 // Note: === is necessary for proper matching of number-like titles.
4536                 return $this->getInterwiki() === $title->getInterwiki()
4537                         && $this->getNamespace() == $title->getNamespace()
4538                         && $this->getDBkey() === $title->getDBkey();
4539         }
4540
4541         /**
4542          * Check if this title is a subpage of another title
4543          *
4544          * @param $title Title
4545          * @return Bool
4546          */
4547         public function isSubpageOf( Title $title ) {
4548                 return $this->getInterwiki() === $title->getInterwiki()
4549                         && $this->getNamespace() == $title->getNamespace()
4550                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4551         }
4552
4553         /**
4554          * Check if page exists.  For historical reasons, this function simply
4555          * checks for the existence of the title in the page table, and will
4556          * thus return false for interwiki links, special pages and the like.
4557          * If you want to know if a title can be meaningfully viewed, you should
4558          * probably call the isKnown() method instead.
4559          *
4560          * @return Bool
4561          */
4562         public function exists() {
4563                 return $this->getArticleID() != 0;
4564         }
4565
4566         /**
4567          * Should links to this title be shown as potentially viewable (i.e. as
4568          * "bluelinks"), even if there's no record by this title in the page
4569          * table?
4570          *
4571          * This function is semi-deprecated for public use, as well as somewhat
4572          * misleadingly named.  You probably just want to call isKnown(), which
4573          * calls this function internally.
4574          *
4575          * (ISSUE: Most of these checks are cheap, but the file existence check
4576          * can potentially be quite expensive.  Including it here fixes a lot of
4577          * existing code, but we might want to add an optional parameter to skip
4578          * it and any other expensive checks.)
4579          *
4580          * @return Bool
4581          */
4582         public function isAlwaysKnown() {
4583                 $isKnown = null;
4584
4585                 /**
4586                  * Allows overriding default behavior for determining if a page exists.
4587                  * If $isKnown is kept as null, regular checks happen. If it's
4588                  * a boolean, this value is returned by the isKnown method.
4589                  *
4590                  * @since 1.20
4591                  *
4592                  * @param Title $title
4593                  * @param boolean|null $isKnown
4594                  */
4595                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4596
4597                 if ( !is_null( $isKnown ) ) {
4598                         return $isKnown;
4599                 }
4600
4601                 if ( $this->isExternal() ) {
4602                         return true;  // any interwiki link might be viewable, for all we know
4603                 }
4604
4605                 switch ( $this->mNamespace ) {
4606                         case NS_MEDIA:
4607                         case NS_FILE:
4608                                 // file exists, possibly in a foreign repo
4609                                 return (bool)wfFindFile( $this );
4610                         case NS_SPECIAL:
4611                                 // valid special page
4612                                 return SpecialPageFactory::exists( $this->getDBkey() );
4613                         case NS_MAIN:
4614                                 // selflink, possibly with fragment
4615                                 return $this->mDbkeyform == '';
4616                         case NS_MEDIAWIKI:
4617                                 // known system message
4618                                 return $this->hasSourceText() !== false;
4619                         default:
4620                                 return false;
4621                 }
4622         }
4623
4624         /**
4625          * Does this title refer to a page that can (or might) be meaningfully
4626          * viewed?  In particular, this function may be used to determine if
4627          * links to the title should be rendered as "bluelinks" (as opposed to
4628          * "redlinks" to non-existent pages).
4629          * Adding something else to this function will cause inconsistency
4630          * since LinkHolderArray calls isAlwaysKnown() and does its own
4631          * page existence check.
4632          *
4633          * @return Bool
4634          */
4635         public function isKnown() {
4636                 return $this->isAlwaysKnown() || $this->exists();
4637         }
4638
4639         /**
4640          * Does this page have source text?
4641          *
4642          * @return Boolean
4643          */
4644         public function hasSourceText() {
4645                 if ( $this->exists() ) {
4646                         return true;
4647                 }
4648
4649                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4650                         // If the page doesn't exist but is a known system message, default
4651                         // message content will be displayed, same for language subpages-
4652                         // Use always content language to avoid loading hundreds of languages
4653                         // to get the link color.
4654                         global $wgContLang;
4655                         list( $name, ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4656                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4657                         return $message->exists();
4658                 }
4659
4660                 return false;
4661         }
4662
4663         /**
4664          * Get the default message text or false if the message doesn't exist
4665          *
4666          * @return String or false
4667          */
4668         public function getDefaultMessageText() {
4669                 global $wgContLang;
4670
4671                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4672                         return false;
4673                 }
4674
4675                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4676                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4677
4678                 if ( $message->exists() ) {
4679                         return $message->plain();
4680                 } else {
4681                         return false;
4682                 }
4683         }
4684
4685         /**
4686          * Updates page_touched for this page; called from LinksUpdate.php
4687          *
4688          * @return Bool true if the update succeeded
4689          */
4690         public function invalidateCache() {
4691                 if ( wfReadOnly() ) {
4692                         return false;
4693                 }
4694
4695                 $method = __METHOD__;
4696                 $dbw = wfGetDB( DB_MASTER );
4697                 $conds = $this->pageCond();
4698                 $dbw->onTransactionIdle( function() use ( $dbw, $conds, $method ) {
4699                         $dbw->update(
4700                                 'page',
4701                                 array( 'page_touched' => $dbw->timestamp() ),
4702                                 $conds,
4703                                 $method
4704                         );
4705                 } );
4706
4707                 return true;
4708         }
4709
4710         /**
4711          * Update page_touched timestamps and send squid purge messages for
4712          * pages linking to this title. May be sent to the job queue depending
4713          * on the number of links. Typically called on create and delete.
4714          */
4715         public function touchLinks() {
4716                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4717                 $u->doUpdate();
4718
4719                 if ( $this->getNamespace() == NS_CATEGORY ) {
4720                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4721                         $u->doUpdate();
4722                 }
4723         }
4724
4725         /**
4726          * Get the last touched timestamp
4727          *
4728          * @param $db DatabaseBase: optional db
4729          * @return String last-touched timestamp
4730          */
4731         public function getTouched( $db = null ) {
4732                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4733                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4734                 return $touched;
4735         }
4736
4737         /**
4738          * Get the timestamp when this page was updated since the user last saw it.
4739          *
4740          * @param $user User
4741          * @return String|Null
4742          */
4743         public function getNotificationTimestamp( $user = null ) {
4744                 global $wgUser, $wgShowUpdatedMarker;
4745                 // Assume current user if none given
4746                 if ( !$user ) {
4747                         $user = $wgUser;
4748                 }
4749                 // Check cache first
4750                 $uid = $user->getId();
4751                 // avoid isset here, as it'll return false for null entries
4752                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4753                         return $this->mNotificationTimestamp[$uid];
4754                 }
4755                 if ( !$uid || !$wgShowUpdatedMarker || !$user->isAllowed( 'viewmywatchlist' ) ) {
4756                         $this->mNotificationTimestamp[$uid] = false;
4757                         return $this->mNotificationTimestamp[$uid];
4758                 }
4759                 // Don't cache too much!
4760                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4761                         $this->mNotificationTimestamp = array();
4762                 }
4763                 $dbr = wfGetDB( DB_SLAVE );
4764                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4765                         'wl_notificationtimestamp',
4766                         array(
4767                                 'wl_user' => $user->getId(),
4768                                 'wl_namespace' => $this->getNamespace(),
4769                                 'wl_title' => $this->getDBkey(),
4770                         ),
4771                         __METHOD__
4772                 );
4773                 return $this->mNotificationTimestamp[$uid];
4774         }
4775
4776         /**
4777          * Generate strings used for xml 'id' names in monobook tabs
4778          *
4779          * @param string $prepend defaults to 'nstab-'
4780          * @return String XML 'id' name
4781          */
4782         public function getNamespaceKey( $prepend = 'nstab-' ) {
4783                 global $wgContLang;
4784                 // Gets the subject namespace if this title
4785                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4786                 // Checks if canonical namespace name exists for namespace
4787                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4788                         // Uses canonical namespace name
4789                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4790                 } else {
4791                         // Uses text of namespace
4792                         $namespaceKey = $this->getSubjectNsText();
4793                 }
4794                 // Makes namespace key lowercase
4795                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4796                 // Uses main
4797                 if ( $namespaceKey == '' ) {
4798                         $namespaceKey = 'main';
4799                 }
4800                 // Changes file to image for backwards compatibility
4801                 if ( $namespaceKey == 'file' ) {
4802                         $namespaceKey = 'image';
4803                 }
4804                 return $prepend . $namespaceKey;
4805         }
4806
4807         /**
4808          * Get all extant redirects to this Title
4809          *
4810          * @param int|Null $ns Single namespace to consider; NULL to consider all namespaces
4811          * @return Title[] Array of Title redirects to this title
4812          */
4813         public function getRedirectsHere( $ns = null ) {
4814                 $redirs = array();
4815
4816                 $dbr = wfGetDB( DB_SLAVE );
4817                 $where = array(
4818                         'rd_namespace' => $this->getNamespace(),
4819                         'rd_title' => $this->getDBkey(),
4820                         'rd_from = page_id'
4821                 );
4822                 if ( $this->isExternal() ) {
4823                         $where['rd_interwiki'] = $this->getInterwiki();
4824                 } else {
4825                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4826                 }
4827                 if ( !is_null( $ns ) ) {
4828                         $where['page_namespace'] = $ns;
4829                 }
4830
4831                 $res = $dbr->select(
4832                         array( 'redirect', 'page' ),
4833                         array( 'page_namespace', 'page_title' ),
4834                         $where,
4835                         __METHOD__
4836                 );
4837
4838                 foreach ( $res as $row ) {
4839                         $redirs[] = self::newFromRow( $row );
4840                 }
4841                 return $redirs;
4842         }
4843
4844         /**
4845          * Check if this Title is a valid redirect target
4846          *
4847          * @return Bool
4848          */
4849         public function isValidRedirectTarget() {
4850                 global $wgInvalidRedirectTargets;
4851
4852                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4853                 if ( $this->isSpecial( 'Userlogout' ) ) {
4854                         return false;
4855                 }
4856
4857                 foreach ( $wgInvalidRedirectTargets as $target ) {
4858                         if ( $this->isSpecial( $target ) ) {
4859                                 return false;
4860                         }
4861                 }
4862
4863                 return true;
4864         }
4865
4866         /**
4867          * Get a backlink cache object
4868          *
4869          * @return BacklinkCache
4870          */
4871         public function getBacklinkCache() {
4872                 return BacklinkCache::get( $this );
4873         }
4874
4875         /**
4876          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4877          *
4878          * @return Boolean
4879          */
4880         public function canUseNoindex() {
4881                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4882
4883                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4884                         ? $wgContentNamespaces
4885                         : $wgExemptFromUserRobotsControl;
4886
4887                 return !in_array( $this->mNamespace, $bannedNamespaces );
4888
4889         }
4890
4891         /**
4892          * Returns the raw sort key to be used for categories, with the specified
4893          * prefix.  This will be fed to Collation::getSortKey() to get a
4894          * binary sortkey that can be used for actual sorting.
4895          *
4896          * @param string $prefix The prefix to be used, specified using
4897          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4898          *   prefix.
4899          * @return string
4900          */
4901         public function getCategorySortkey( $prefix = '' ) {
4902                 $unprefixed = $this->getText();
4903
4904                 // Anything that uses this hook should only depend
4905                 // on the Title object passed in, and should probably
4906                 // tell the users to run updateCollations.php --force
4907                 // in order to re-sort existing category relations.
4908                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4909                 if ( $prefix !== '' ) {
4910                         # Separate with a line feed, so the unprefixed part is only used as
4911                         # a tiebreaker when two pages have the exact same prefix.
4912                         # In UCA, tab is the only character that can sort above LF
4913                         # so we strip both of them from the original prefix.
4914                         $prefix = strtr( $prefix, "\n\t", '  ' );
4915                         return "$prefix\n$unprefixed";
4916                 }
4917                 return $unprefixed;
4918         }
4919
4920         /**
4921          * Get the language in which the content of this page is written in
4922          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4923          * e.g. $wgLang (such as special pages, which are in the user language).
4924          *
4925          * @since 1.18
4926          * @return Language
4927          */
4928         public function getPageLanguage() {
4929                 global $wgLang, $wgLanguageCode;
4930                 wfProfileIn( __METHOD__ );
4931                 if ( $this->isSpecialPage() ) {
4932                         // special pages are in the user language
4933                         wfProfileOut( __METHOD__ );
4934                         return $wgLang;
4935                 }
4936
4937                 if ( !$this->mPageLanguage || $this->mPageLanguage[1] !== $wgLanguageCode ) {
4938                         // Note that this may depend on user settings, so the cache should be only per-request.
4939                         // NOTE: ContentHandler::getPageLanguage() may need to load the content to determine the page language!
4940                         // Checking $wgLanguageCode hasn't changed for the benefit of unit tests.
4941                         $contentHandler = ContentHandler::getForTitle( $this );
4942                         $langObj = wfGetLangObj( $contentHandler->getPageLanguage( $this ) );
4943                         $this->mPageLanguage = array( $langObj->getCode(), $wgLanguageCode );
4944                 } else {
4945                         $langObj = wfGetLangObj( $this->mPageLanguage[0] );
4946                 }
4947                 wfProfileOut( __METHOD__ );
4948                 return $langObj;
4949         }
4950
4951         /**
4952          * Get the language in which the content of this page is written when
4953          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4954          * e.g. $wgLang (such as special pages, which are in the user language).
4955          *
4956          * @since 1.20
4957          * @return Language
4958          */
4959         public function getPageViewLanguage() {
4960                 global $wgLang;
4961
4962                 if ( $this->isSpecialPage() ) {
4963                         // If the user chooses a variant, the content is actually
4964                         // in a language whose code is the variant code.
4965                         $variant = $wgLang->getPreferredVariant();
4966                         if ( $wgLang->getCode() !== $variant ) {
4967                                 return Language::factory( $variant );
4968                         }
4969
4970                         return $wgLang;
4971                 }
4972
4973                 //NOTE: can't be cached persistently, depends on user settings
4974                 //NOTE: ContentHandler::getPageViewLanguage() may need to load the content to determine the page language!
4975                 $contentHandler = ContentHandler::getForTitle( $this );
4976                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4977                 return $pageLang;
4978         }
4979
4980         /**
4981          * Get a list of rendered edit notices for this page.
4982          *
4983          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4984          * they will already be wrapped in paragraphs.
4985          *
4986          * @since 1.21
4987          * @param int oldid Revision ID that's being edited
4988          * @return Array
4989          */
4990         public function getEditNotices( $oldid = 0 ) {
4991                 $notices = array();
4992
4993                 # Optional notices on a per-namespace and per-page basis
4994                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4995                 $editnotice_ns_message = wfMessage( $editnotice_ns );
4996                 if ( $editnotice_ns_message->exists() ) {
4997                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
4998                 }
4999                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
5000                         $parts = explode( '/', $this->getDBkey() );
5001                         $editnotice_base = $editnotice_ns;
5002                         while ( count( $parts ) > 0 ) {
5003                                 $editnotice_base .= '-' . array_shift( $parts );
5004                                 $editnotice_base_msg = wfMessage( $editnotice_base );
5005                                 if ( $editnotice_base_msg->exists() ) {
5006                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
5007                                 }
5008                         }
5009                 } else {
5010                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
5011                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
5012                         $editnoticeMsg = wfMessage( $editnoticeText );
5013                         if ( $editnoticeMsg->exists() ) {
5014                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
5015                         }
5016                 }
5017
5018                 wfRunHooks( 'TitleGetEditNotices', array( $this, $oldid, &$notices ) );
5019                 return $notices;
5020         }
5021 }