includes/Title.php

   1 <?php
   2 /**
   3  * Representation a title within %MediaWiki.
   4  *
   5  * See title.txt
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  */
  24
  25 /**
  26  * Represents a title within MediaWiki.
  27  * Optionally may contain an interwiki designation or namespace.
  28  * @note This class can fetch various kinds of data from the database;
  29  *       however, it does so inefficiently.
  30  *
  31  * @internal documentation reviewed 15 Mar 2010
  32  */
  33 class Title {
  34         /** @name Static cache variables */
  35         // @{
  36         static private $titleCache = array();
  37         // @}
  38
  39         /**
  40          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  41          * commonly used titles. On a batch operation this can become a memory leak
  42          * if not bounded. After hitting this many titles reset the cache.
  43          */
  44         const CACHE_MAX = 1000;
  45
  46         /**
  47          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  48          * to use the master DB
  49          */
  50         const GAID_FOR_UPDATE = 1;
  51
  52         /**
  53          * @name Private member variables
  54          * Please use the accessor functions instead.
  55          * @private
  56          */
  57         // @{
  58
  59         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  60         var $mUrlform = '';               // /< URL-encoded form of the main part
  61         var $mDbkeyform = '';             // /< Main part with underscores
  62         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  63         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  64         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  65         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  66         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  67         var $mLatestID = false;           // /< ID of most recent revision
  68         var $mContentModel = false;       // /< ID of the page's content model, i.e. one of the CONTENT_MODEL_XXX constants
  69         private $mEstimateRevisions;      // /< Estimated number of revisions; null of not loaded
  70         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  71         var $mOldRestrictions = false;
  72         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  73         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  74         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  75         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  76         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  77         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  78         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  79         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  80         # Don't change the following default, NS_MAIN is hardcoded in several
  81         # places.  See bug 696.
  82         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  83                                                                           # Zero except in {{transclusion}} tags
  84         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  85         var $mLength = -1;                // /< The page length, 0 for special pages
  86         var $mRedirect = null;            // /< Is the article at this title a redirect?
  87         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  88         var $mBacklinkCache = null;       // /< Cache of links to this title
  89         var $mHasSubpage;                 // /< Whether a page has any subpages
  90         // @}
  91
  92
  93         /**
  94          * Constructor
  95          */
  96         /*protected*/ function __construct() { }
  97
  98         /**
  99          * Create a new Title from a prefixed DB key
 100          *
 101          * @param $key String the database key, which has underscores
 102          *      instead of spaces, possibly including namespace and
 103          *      interwiki prefixes
 104          * @return Title, or NULL on an error
 105          */
 106         public static function newFromDBkey( $key ) {
 107                 $t = new Title();
 108                 $t->mDbkeyform = $key;
 109                 if ( $t->secureAndSplit() ) {
 110                         return $t;
 111                 } else {
 112                         return null;
 113                 }
 114         }
 115
 116         /**
 117          * Create a new Title from text, such as what one would find in a link. De-
 118          * codes any HTML entities in the text.
 119          *
 120          * @param $text String the link text; spaces, prefixes, and an
 121          *   initial ':' indicating the main namespace are accepted.
 122          * @param $defaultNamespace Int the namespace to use if none is speci-
 123          *   fied by a prefix.  If you want to force a specific namespace even if
 124          *   $text might begin with a namespace prefix, use makeTitle() or
 125          *   makeTitleSafe().
 126          * @throws MWException
 127          * @return Title|null - Title or null on an error.
 128          */
 129         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 130                 if ( is_object( $text ) ) {
 131                         throw new MWException( 'Title::newFromText given an object' );
 132                 }
 133
 134                 /**
 135                  * Wiki pages often contain multiple links to the same page.
 136                  * Title normalization and parsing can become expensive on
 137                  * pages with many links, so we can save a little time by
 138                  * caching them.
 139                  *
 140                  * In theory these are value objects and won't get changed...
 141                  */
 142                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 143                         return Title::$titleCache[$text];
 144                 }
 145
 146                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 147                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 148
 149                 $t = new Title();
 150                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 151                 $t->mDefaultNamespace = $defaultNamespace;
 152
 153                 static $cachedcount = 0 ;
 154                 if ( $t->secureAndSplit() ) {
 155                         if ( $defaultNamespace == NS_MAIN ) {
 156                                 if ( $cachedcount >= self::CACHE_MAX ) {
 157                                         # Avoid memory leaks on mass operations...
 158                                         Title::$titleCache = array();
 159                                         $cachedcount = 0;
 160                                 }
 161                                 $cachedcount++;
 162                                 Title::$titleCache[$text] =& $t;
 163                         }
 164                         return $t;
 165                 } else {
 166                         $ret = null;
 167                         return $ret;
 168                 }
 169         }
 170
 171         /**
 172          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 173          *
 174          * Example of wrong and broken code:
 175          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 176          *
 177          * Example of right code:
 178          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 179          *
 180          * Create a new Title from URL-encoded text. Ensures that
 181          * the given title's length does not exceed the maximum.
 182          *
 183          * @param $url String the title, as might be taken from a URL
 184          * @return Title the new object, or NULL on an error
 185          */
 186         public static function newFromURL( $url ) {
 187                 $t = new Title();
 188
 189                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 190                 # but some URLs used it as a space replacement and they still come
 191                 # from some external search tools.
 192                 if ( strpos( self::legalChars(), '+' ) === false ) {
 193                         $url = str_replace( '+', ' ', $url );
 194                 }
 195
 196                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 197                 if ( $t->secureAndSplit() ) {
 198                         return $t;
 199                 } else {
 200                         return null;
 201                 }
 202         }
 203
 204         /**
 205          * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 206          * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
 207          *
 208          * @return array
 209          */
 210         protected static function getSelectFields() {
 211                 global $wgContentHandlerUseDB;
 212
 213                 $fields = array(
 214                         'page_namespace', 'page_title', 'page_id',
 215                         'page_len', 'page_is_redirect', 'page_latest',
 216                 );
 217
 218                 if ( $wgContentHandlerUseDB ) {
 219                         $fields[] = 'page_content_model';
 220                 }
 221
 222                 return $fields;
 223         }
 224
 225         /**
 226          * Create a new Title from an article ID
 227          *
 228          * @param $id Int the page_id corresponding to the Title to create
 229          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 230          * @return Title the new object, or NULL on an error
 231          */
 232         public static function newFromID( $id, $flags = 0 ) {
 233                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 234                 $row = $db->selectRow(
 235                         'page',
 236                         self::getSelectFields(),
 237                         array( 'page_id' => $id ),
 238                         __METHOD__
 239                 );
 240                 if ( $row !== false ) {
 241                         $title = Title::newFromRow( $row );
 242                 } else {
 243                         $title = null;
 244                 }
 245                 return $title;
 246         }
 247
 248         /**
 249          * Make an array of titles from an array of IDs
 250          *
 251          * @param $ids Array of Int Array of IDs
 252          * @return Array of Titles
 253          */
 254         public static function newFromIDs( $ids ) {
 255                 if ( !count( $ids ) ) {
 256                         return array();
 257                 }
 258                 $dbr = wfGetDB( DB_SLAVE );
 259
 260                 $res = $dbr->select(
 261                         'page',
 262                         self::getSelectFields(),
 263                         array( 'page_id' => $ids ),
 264                         __METHOD__
 265                 );
 266
 267                 $titles = array();
 268                 foreach ( $res as $row ) {
 269                         $titles[] = Title::newFromRow( $row );
 270                 }
 271                 return $titles;
 272         }
 273
 274         /**
 275          * Make a Title object from a DB row
 276          *
 277          * @param $row Object database row (needs at least page_title,page_namespace)
 278          * @return Title corresponding Title
 279          */
 280         public static function newFromRow( $row ) {
 281                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 282                 $t->loadFromRow( $row );
 283                 return $t;
 284         }
 285
 286         /**
 287          * Load Title object fields from a DB row.
 288          * If false is given, the title will be treated as non-existing.
 289          *
 290          * @param $row Object|bool database row
 291          */
 292         public function loadFromRow( $row ) {
 293                 if ( $row ) { // page found
 294                         if ( isset( $row->page_id ) )
 295                                 $this->mArticleID = (int)$row->page_id;
 296                         if ( isset( $row->page_len ) )
 297                                 $this->mLength = (int)$row->page_len;
 298                         if ( isset( $row->page_is_redirect ) )
 299                                 $this->mRedirect = (bool)$row->page_is_redirect;
 300                         if ( isset( $row->page_latest ) )
 301                                 $this->mLatestID = (int)$row->page_latest;
 302                         if ( isset( $row->page_content_model ) )
 303                                 $this->mContentModel = intval( $row->page_content_model );
 304                         else
 305                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 306                 } else { // page not found
 307                         $this->mArticleID = 0;
 308                         $this->mLength = 0;
 309                         $this->mRedirect = false;
 310                         $this->mLatestID = 0;
 311                         $this->mContentModel = false; # initialized lazily in getContentModel()
 312                 }
 313         }
 314
 315         /**
 316          * Create a new Title from a namespace index and a DB key.
 317          * It's assumed that $ns and $title are *valid*, for instance when
 318          * they came directly from the database or a special page name.
 319          * For convenience, spaces are converted to underscores so that
 320          * eg user_text fields can be used directly.
 321          *
 322          * @param $ns Int the namespace of the article
 323          * @param $title String the unprefixed database key form
 324          * @param $fragment String the link fragment (after the "#")
 325          * @param $interwiki String the interwiki prefix
 326          * @return Title the new object
 327          */
 328         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 329                 $t = new Title();
 330                 $t->mInterwiki = $interwiki;
 331                 $t->mFragment = $fragment;
 332                 $t->mNamespace = $ns = intval( $ns );
 333                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 334                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 335                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 336                 $t->mTextform = str_replace( '_', ' ', $title );
 337                 $t->mContentModel = false; # initialized lazily in getContentModel()
 338                 return $t;
 339         }
 340
 341         /**
 342          * Create a new Title from a namespace index and a DB key.
 343          * The parameters will be checked for validity, which is a bit slower
 344          * than makeTitle() but safer for user-provided data.
 345          *
 346          * @param $ns Int the namespace of the article
 347          * @param $title String database key form
 348          * @param $fragment String the link fragment (after the "#")
 349          * @param $interwiki String interwiki prefix
 350          * @return Title the new object, or NULL on an error
 351          */
 352         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 353                 if ( !MWNamespace::exists( $ns ) ) {
 354                         return null;
 355                 }
 356
 357                 $t = new Title();
 358                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 359                 if ( $t->secureAndSplit() ) {
 360                         return $t;
 361                 } else {
 362                         return null;
 363                 }
 364         }
 365
 366         /**
 367          * Create a new Title for the Main Page
 368          *
 369          * @return Title the new object
 370          */
 371         public static function newMainPage() {
 372                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 373                 // Don't give fatal errors if the message is broken
 374                 if ( !$title ) {
 375                         $title = Title::newFromText( 'Main Page' );
 376                 }
 377                 return $title;
 378         }
 379
 380         /**
 381          * Extract a redirect destination from a string and return the
 382          * Title, or null if the text doesn't contain a valid redirect
 383          * This will only return the very next target, useful for
 384          * the redirect table and other checks that don't need full recursion
 385          *
 386          * @param $text String: Text with possible redirect
 387          * @return Title: The corresponding Title
 388          * @deprecated since 1.WD, use Content::getRedirectTarget instead.
 389          */
 390         public static function newFromRedirect( $text ) {
 391                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 392                 return $content->getRedirectTarget();
 393         }
 394
 395         /**
 396          * Extract a redirect destination from a string and return the
 397          * Title, or null if the text doesn't contain a valid redirect
 398          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 399          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 400          *
 401          * @param $text String Text with possible redirect
 402          * @return Title
 403          * @deprecated since 1.WD, use Content::getUltimateRedirectTarget instead.
 404          */
 405         public static function newFromRedirectRecurse( $text ) {
 406                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 407                 return $content->getUltimateRedirectTarget();
 408         }
 409
 410         /**
 411          * Extract a redirect destination from a string and return an
 412          * array of Titles, or null if the text doesn't contain a valid redirect
 413          * The last element in the array is the final destination after all redirects
 414          * have been resolved (up to $wgMaxRedirects times)
 415          *
 416          * @param $text String Text with possible redirect
 417          * @return Array of Titles, with the destination last
 418          * @deprecated since 1.WD, use Content::getRedirectChain instead.
 419          * @todo: migrate this logic into WikitextContent!
 420          */
 421         public static function newFromRedirectArray( $text ) {
 422                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 423                 return $content->getRedirectChain();
 424         }
 425
 426         /**
 427          * Get the prefixed DB key associated with an ID
 428          *
 429          * @param $id Int the page_id of the article
 430          * @return Title an object representing the article, or NULL if no such article was found
 431          */
 432         public static function nameOf( $id ) {
 433                 $dbr = wfGetDB( DB_SLAVE );
 434
 435                 $s = $dbr->selectRow(
 436                         'page',
 437                         array( 'page_namespace', 'page_title' ),
 438                         array( 'page_id' => $id ),
 439                         __METHOD__
 440                 );
 441                 if ( $s === false ) {
 442                         return null;
 443                 }
 444
 445                 $n = self::makeName( $s->page_namespace, $s->page_title );
 446                 return $n;
 447         }
 448
 449         /**
 450          * Get a regex character class describing the legal characters in a link
 451          *
 452          * @return String the list of characters, not delimited
 453          */
 454         public static function legalChars() {
 455                 global $wgLegalTitleChars;
 456                 return $wgLegalTitleChars;
 457         }
 458
 459         /**
 460          * Returns a simple regex that will match on characters and sequences invalid in titles.
 461          * Note that this doesn't pick up many things that could be wrong with titles, but that
 462          * replacing this regex with something valid will make many titles valid.
 463          *
 464          * @return String regex string
 465          */
 466         static function getTitleInvalidRegex() {
 467                 static $rxTc = false;
 468                 if ( !$rxTc ) {
 469                         # Matching titles will be held as illegal.
 470                         $rxTc = '/' .
 471                                 # Any character not allowed is forbidden...
 472                                 '[^' . self::legalChars() . ']' .
 473                                 # URL percent encoding sequences interfere with the ability
 474                                 # to round-trip titles -- you can't link to them consistently.
 475                                 '|%[0-9A-Fa-f]{2}' .
 476                                 # XML/HTML character references produce similar issues.
 477                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 478                                 '|&#[0-9]+;' .
 479                                 '|&#x[0-9A-Fa-f]+;' .
 480                                 '/S';
 481                 }
 482
 483                 return $rxTc;
 484         }
 485
 486         /**
 487          * Get a string representation of a title suitable for
 488          * including in a search index
 489          *
 490          * @param $ns Int a namespace index
 491          * @param $title String text-form main part
 492          * @return String a stripped-down title string ready for the search index
 493          */
 494         public static function indexTitle( $ns, $title ) {
 495                 global $wgContLang;
 496
 497                 $lc = SearchEngine::legalSearchChars() . '&#;';
 498                 $t = $wgContLang->normalizeForSearch( $title );
 499                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 500                 $t = $wgContLang->lc( $t );
 501
 502                 # Handle 's, s'
 503                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 504                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 505
 506                 $t = preg_replace( "/\\s+/", ' ', $t );
 507
 508                 if ( $ns == NS_FILE ) {
 509                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 510                 }
 511                 return trim( $t );
 512         }
 513
 514         /**
 515          * Make a prefixed DB key from a DB key and a namespace index
 516          *
 517          * @param $ns Int numerical representation of the namespace
 518          * @param $title String the DB key form the title
 519          * @param $fragment String The link fragment (after the "#")
 520          * @param $interwiki String The interwiki prefix
 521          * @return String the prefixed form of the title
 522          */
 523         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 524                 global $wgContLang;
 525
 526                 $namespace = $wgContLang->getNsText( $ns );
 527                 $name = $namespace == '' ? $title : "$namespace:$title";
 528                 if ( strval( $interwiki ) != '' ) {
 529                         $name = "$interwiki:$name";
 530                 }
 531                 if ( strval( $fragment ) != '' ) {
 532                         $name .= '#' . $fragment;
 533                 }
 534                 return $name;
 535         }
 536
 537         /**
 538          * Escape a text fragment, say from a link, for a URL
 539          *
 540          * @param $fragment string containing a URL or link fragment (after the "#")
 541          * @return String: escaped string
 542          */
 543         static function escapeFragmentForURL( $fragment ) {
 544                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 545                 # fragments appear not to work in IE (at least up to 7) or in at least
 546                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 547                 # to care if they aren't encoded.
 548                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 549         }
 550
 551         /**
 552          * Callback for usort() to do title sorts by (namespace, title)
 553          *
 554          * @param $a Title
 555          * @param $b Title
 556          *
 557          * @return Integer: result of string comparison, or namespace comparison
 558          */
 559         public static function compare( $a, $b ) {
 560                 if ( $a->getNamespace() == $b->getNamespace() ) {
 561                         return strcmp( $a->getText(), $b->getText() );
 562                 } else {
 563                         return $a->getNamespace() - $b->getNamespace();
 564                 }
 565         }
 566
 567         /**
 568          * Determine whether the object refers to a page within
 569          * this project.
 570          *
 571          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 572          */
 573         public function isLocal() {
 574                 if ( $this->mInterwiki != '' ) {
 575                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 576                 } else {
 577                         return true;
 578                 }
 579         }
 580
 581         /**
 582          * Is this Title interwiki?
 583          *
 584          * @return Bool
 585          */
 586         public function isExternal() {
 587                 return ( $this->mInterwiki != '' );
 588         }
 589
 590         /**
 591          * Get the interwiki prefix (or null string)
 592          *
 593          * @return String Interwiki prefix
 594          */
 595         public function getInterwiki() {
 596                 return $this->mInterwiki;
 597         }
 598
 599         /**
 600          * Determine whether the object refers to a page within
 601          * this project and is transcludable.
 602          *
 603          * @return Bool TRUE if this is transcludable
 604          */
 605         public function isTrans() {
 606                 if ( $this->mInterwiki == '' ) {
 607                         return false;
 608                 }
 609
 610                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 611         }
 612
 613         /**
 614          * Returns the DB name of the distant wiki which owns the object.
 615          *
 616          * @return String the DB name
 617          */
 618         public function getTransWikiID() {
 619                 if ( $this->mInterwiki == '' ) {
 620                         return false;
 621                 }
 622
 623                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 624         }
 625
 626         /**
 627          * Get the text form (spaces not underscores) of the main part
 628          *
 629          * @return String Main part of the title
 630          */
 631         public function getText() {
 632                 return $this->mTextform;
 633         }
 634
 635         /**
 636          * Get the URL-encoded form of the main part
 637          *
 638          * @return String Main part of the title, URL-encoded
 639          */
 640         public function getPartialURL() {
 641                 return $this->mUrlform;
 642         }
 643
 644         /**
 645          * Get the main part with underscores
 646          *
 647          * @return String: Main part of the title, with underscores
 648          */
 649         public function getDBkey() {
 650                 return $this->mDbkeyform;
 651         }
 652
 653         /**
 654          * Get the DB key with the initial letter case as specified by the user
 655          *
 656          * @return String DB key
 657          */
 658         function getUserCaseDBKey() {
 659                 return $this->mUserCaseDBKey;
 660         }
 661
 662         /**
 663          * Get the namespace index, i.e. one of the NS_xxxx constants.
 664          *
 665          * @return Integer: Namespace index
 666          */
 667         public function getNamespace() {
 668                 return $this->mNamespace;
 669         }
 670
 671         /**
 672          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 673          *
 674          * @return Integer: Content model id
 675          */
 676         public function getContentModel() {
 677                 if ( !$this->mContentModel ) {
 678                         $linkCache = LinkCache::singleton();
 679                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 680                 }
 681
 682                 if ( !$this->mContentModel ) {
 683                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 684                 }
 685
 686                 if( !$this->mContentModel ) {
 687                         throw new MWException( "failed to determin content model!" );
 688                 }
 689
 690                 return $this->mContentModel;
 691         }
 692
 693         /**
 694          * Convenience method for checking a title's content model name
 695          *
 696          * @param int $id
 697          * @return Boolean true if $this->getContentModel() == $id
 698          */
 699         public function hasContentModel( $id ) {
 700                 return $this->getContentModel() == $id;
 701         }
 702
 703         /**
 704          * Get the namespace text
 705          *
 706          * @return String: Namespace text
 707          */
 708         public function getNsText() {
 709                 global $wgContLang;
 710
 711                 if ( $this->mInterwiki != '' ) {
 712                         // This probably shouldn't even happen. ohh man, oh yuck.
 713                         // But for interwiki transclusion it sometimes does.
 714                         // Shit. Shit shit shit.
 715                         //
 716                         // Use the canonical namespaces if possible to try to
 717                         // resolve a foreign namespace.
 718                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 719                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 720                         }
 721                 }
 722
 723                 if ( $wgContLang->needsGenderDistinction() &&
 724                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 725                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 726                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 727                 }
 728
 729                 return $wgContLang->getNsText( $this->mNamespace );
 730         }
 731
 732         /**
 733          * Get the namespace text of the subject (rather than talk) page
 734          *
 735          * @return String Namespace text
 736          */
 737         public function getSubjectNsText() {
 738                 global $wgContLang;
 739                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 740         }
 741
 742         /**
 743          * Get the namespace text of the talk page
 744          *
 745          * @return String Namespace text
 746          */
 747         public function getTalkNsText() {
 748                 global $wgContLang;
 749                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 750         }
 751
 752         /**
 753          * Could this title have a corresponding talk page?
 754          *
 755          * @return Bool TRUE or FALSE
 756          */
 757         public function canTalk() {
 758                 return( MWNamespace::canTalk( $this->mNamespace ) );
 759         }
 760
 761         /**
 762          * Is this in a namespace that allows actual pages?
 763          *
 764          * @return Bool
 765          * @internal note -- uses hardcoded namespace index instead of constants
 766          */
 767         public function canExist() {
 768                 return $this->mNamespace >= NS_MAIN;
 769         }
 770
 771         /**
 772          * Can this title be added to a user's watchlist?
 773          *
 774          * @return Bool TRUE or FALSE
 775          */
 776         public function isWatchable() {
 777                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 778         }
 779
 780         /**
 781          * Returns true if this is a special page.
 782          *
 783          * @return boolean
 784          */
 785         public function isSpecialPage() {
 786                 return $this->getNamespace() == NS_SPECIAL;
 787         }
 788
 789         /**
 790          * Returns true if this title resolves to the named special page
 791          *
 792          * @param $name String The special page name
 793          * @return boolean
 794          */
 795         public function isSpecial( $name ) {
 796                 if ( $this->isSpecialPage() ) {
 797                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 798                         if ( $name == $thisName ) {
 799                                 return true;
 800                         }
 801                 }
 802                 return false;
 803         }
 804
 805         /**
 806          * If the Title refers to a special page alias which is not the local default, resolve
 807          * the alias, and localise the name as necessary.  Otherwise, return $this
 808          *
 809          * @return Title
 810          */
 811         public function fixSpecialName() {
 812                 if ( $this->isSpecialPage() ) {
 813                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 814                         if ( $canonicalName ) {
 815                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 816                                 if ( $localName != $this->mDbkeyform ) {
 817                                         return Title::makeTitle( NS_SPECIAL, $localName );
 818                                 }
 819                         }
 820                 }
 821                 return $this;
 822         }
 823
 824         /**
 825          * Returns true if the title is inside the specified namespace.
 826          *
 827          * Please make use of this instead of comparing to getNamespace()
 828          * This function is much more resistant to changes we may make
 829          * to namespaces than code that makes direct comparisons.
 830          * @param $ns int The namespace
 831          * @return bool
 832          * @since 1.19
 833          */
 834         public function inNamespace( $ns ) {
 835                 return MWNamespace::equals( $this->getNamespace(), $ns );
 836         }
 837
 838         /**
 839          * Returns true if the title is inside one of the specified namespaces.
 840          *
 841          * @param ...$namespaces The namespaces to check for
 842          * @return bool
 843          * @since 1.19
 844          */
 845         public function inNamespaces( /* ... */ ) {
 846                 $namespaces = func_get_args();
 847                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 848                         $namespaces = $namespaces[0];
 849                 }
 850
 851                 foreach ( $namespaces as $ns ) {
 852                         if ( $this->inNamespace( $ns ) ) {
 853                                 return true;
 854                         }
 855                 }
 856
 857                 return false;
 858         }
 859
 860         /**
 861          * Returns true if the title has the same subject namespace as the
 862          * namespace specified.
 863          * For example this method will take NS_USER and return true if namespace
 864          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 865          * as their subject namespace.
 866          *
 867          * This is MUCH simpler than individually testing for equivilance
 868          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 869          * @since 1.19
 870          * @param $ns int
 871          * @return bool
 872          */
 873         public function hasSubjectNamespace( $ns ) {
 874                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 875         }
 876
 877         /**
 878          * Is this Title in a namespace which contains content?
 879          * In other words, is this a content page, for the purposes of calculating
 880          * statistics, etc?
 881          *
 882          * @return Boolean
 883          */
 884         public function isContentPage() {
 885                 return MWNamespace::isContent( $this->getNamespace() );
 886         }
 887
 888         /**
 889          * Would anybody with sufficient privileges be able to move this page?
 890          * Some pages just aren't movable.
 891          *
 892          * @return Bool TRUE or FALSE
 893          */
 894         public function isMovable() {
 895                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 896                         // Interwiki title or immovable namespace. Hooks don't get to override here
 897                         return false;
 898                 }
 899
 900                 $result = true;
 901                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 902                 return $result;
 903         }
 904
 905         /**
 906          * Is this the mainpage?
 907          * @note Title::newFromText seams to be sufficiently optimized by the title
 908          * cache that we don't need to over-optimize by doing direct comparisons and
 909          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 910          * ends up reporting something differently than $title->isMainPage();
 911          *
 912          * @since 1.18
 913          * @return Bool
 914          */
 915         public function isMainPage() {
 916                 return $this->equals( Title::newMainPage() );
 917         }
 918
 919         /**
 920          * Is this a subpage?
 921          *
 922          * @return Bool
 923          */
 924         public function isSubpage() {
 925                 return MWNamespace::hasSubpages( $this->mNamespace )
 926                         ? strpos( $this->getText(), '/' ) !== false
 927                         : false;
 928         }
 929
 930         /**
 931          * Is this a conversion table for the LanguageConverter?
 932          *
 933          * @return Bool
 934          */
 935         public function isConversionTable() {
 936                 return $this->getNamespace() == NS_MEDIAWIKI &&
 937                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 938         }
 939
 940         /**
 941          * Does that page contain wikitext, or it is JS, CSS or whatever?
 942          *
 943          * @return Bool
 944          */
 945         public function isWikitextPage() {
 946                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
 947         }
 948
 949         /**
 950          * Could this page contain custom CSS or JavaScript for the global UI.
 951          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
 952          * or CONTENT_MODEL_JAVASCRIPT.
 953          *
 954          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
 955          *
 956          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
 957          *
 958          * @return Bool
 959          */
 960         public function isCssOrJsPage() {
 961                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
 962                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 963                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
 964
 965                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
 966                 #      hook funktions can force this method to return true even outside the mediawiki namespace.
 967
 968                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
 969
 970                 return $isCssOrJsPage;
 971         }
 972
 973         /**
 974          * Is this a .css or .js subpage of a user page?
 975          * @return Bool
 976          */
 977         public function isCssJsSubpage() {
 978                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
 979                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 980                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
 981         }
 982
 983         /**
 984          * Trim down a .css or .js subpage title to get the corresponding skin name
 985          *
 986          * @return string containing skin name from .css or .js subpage title
 987          */
 988         public function getSkinFromCssJsSubpage() {
 989                 $subpage = explode( '/', $this->mTextform );
 990                 $subpage = $subpage[ count( $subpage ) - 1 ];
 991                 $lastdot = strrpos( $subpage, '.' );
 992                 if ( $lastdot === false )
 993                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
 994                 return substr( $subpage, 0, $lastdot );
 995         }
 996
 997         /**
 998          * Is this a .css subpage of a user page?
 999          *
1000          * @return Bool
1001          */
1002         public function isCssSubpage() {
1003                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1004                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1005         }
1006
1007         /**
1008          * Is this a .js subpage of a user page?
1009          *
1010          * @return Bool
1011          */
1012         public function isJsSubpage() {
1013                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1014                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1015         }
1016
1017         /**
1018          * Is this a talk page of some sort?
1019          *
1020          * @return Bool
1021          */
1022         public function isTalkPage() {
1023                 return MWNamespace::isTalk( $this->getNamespace() );
1024         }
1025
1026         /**
1027          * Get a Title object associated with the talk page of this article
1028          *
1029          * @return Title the object for the talk page
1030          */
1031         public function getTalkPage() {
1032                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1033         }
1034
1035         /**
1036          * Get a title object associated with the subject page of this
1037          * talk page
1038          *
1039          * @return Title the object for the subject page
1040          */
1041         public function getSubjectPage() {
1042                 // Is this the same title?
1043                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1044                 if ( $this->getNamespace() == $subjectNS ) {
1045                         return $this;
1046                 }
1047                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1048         }
1049
1050         /**
1051          * Get the default namespace index, for when there is no namespace
1052          *
1053          * @return Int Default namespace index
1054          */
1055         public function getDefaultNamespace() {
1056                 return $this->mDefaultNamespace;
1057         }
1058
1059         /**
1060          * Get title for search index
1061          *
1062          * @return String a stripped-down title string ready for the
1063          *  search index
1064          */
1065         public function getIndexTitle() {
1066                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1067         }
1068
1069         /**
1070          * Get the Title fragment (i.e.\ the bit after the #) in text form
1071          *
1072          * @return String Title fragment
1073          */
1074         public function getFragment() {
1075                 return $this->mFragment;
1076         }
1077
1078         /**
1079          * Get the fragment in URL form, including the "#" character if there is one
1080          * @return String Fragment in URL form
1081          */
1082         public function getFragmentForURL() {
1083                 if ( $this->mFragment == '' ) {
1084                         return '';
1085                 } else {
1086                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1087                 }
1088         }
1089
1090         /**
1091          * Set the fragment for this title. Removes the first character from the
1092          * specified fragment before setting, so it assumes you're passing it with
1093          * an initial "#".
1094          *
1095          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1096          * Still in active use privately.
1097          *
1098          * @param $fragment String text
1099          */
1100         public function setFragment( $fragment ) {
1101                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1102         }
1103
1104         /**
1105          * Prefix some arbitrary text with the namespace or interwiki prefix
1106          * of this object
1107          *
1108          * @param $name String the text
1109          * @return String the prefixed text
1110          * @private
1111          */
1112         private function prefix( $name ) {
1113                 $p = '';
1114                 if ( $this->mInterwiki != '' ) {
1115                         $p = $this->mInterwiki . ':';
1116                 }
1117
1118                 if ( 0 != $this->mNamespace ) {
1119                         $p .= $this->getNsText() . ':';
1120                 }
1121                 return $p . $name;
1122         }
1123
1124         /**
1125          * Get the prefixed database key form
1126          *
1127          * @return String the prefixed title, with underscores and
1128          *  any interwiki and namespace prefixes
1129          */
1130         public function getPrefixedDBkey() {
1131                 $s = $this->prefix( $this->mDbkeyform );
1132                 $s = str_replace( ' ', '_', $s );
1133                 return $s;
1134         }
1135
1136         /**
1137          * Get the prefixed title with spaces.
1138          * This is the form usually used for display
1139          *
1140          * @return String the prefixed title, with spaces
1141          */
1142         public function getPrefixedText() {
1143                 // @todo FIXME: Bad usage of empty() ?
1144                 if ( empty( $this->mPrefixedText ) ) {
1145                         $s = $this->prefix( $this->mTextform );
1146                         $s = str_replace( '_', ' ', $s );
1147                         $this->mPrefixedText = $s;
1148                 }
1149                 return $this->mPrefixedText;
1150         }
1151
1152         /**
1153          * Return a string representation of this title
1154          *
1155          * @return String representation of this title
1156          */
1157         public function __toString() {
1158                 return $this->getPrefixedText();
1159         }
1160
1161         /**
1162          * Get the prefixed title with spaces, plus any fragment
1163          * (part beginning with '#')
1164          *
1165          * @return String the prefixed title, with spaces and the fragment, including '#'
1166          */
1167         public function getFullText() {
1168                 $text = $this->getPrefixedText();
1169                 if ( $this->mFragment != '' ) {
1170                         $text .= '#' . $this->mFragment;
1171                 }
1172                 return $text;
1173         }
1174
1175         /**
1176          * Get the base page name, i.e. the leftmost part before any slashes
1177          *
1178          * @return String Base name
1179          */
1180         public function getBaseText() {
1181                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1182                         return $this->getText();
1183                 }
1184
1185                 $parts = explode( '/', $this->getText() );
1186                 # Don't discard the real title if there's no subpage involved
1187                 if ( count( $parts ) > 1 ) {
1188                         unset( $parts[count( $parts ) - 1] );
1189                 }
1190                 return implode( '/', $parts );
1191         }
1192
1193         /**
1194          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1195          *
1196          * @return String Subpage name
1197          */
1198         public function getSubpageText() {
1199                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1200                         return( $this->mTextform );
1201                 }
1202                 $parts = explode( '/', $this->mTextform );
1203                 return( $parts[count( $parts ) - 1] );
1204         }
1205
1206         /**
1207          * Get the HTML-escaped displayable text form.
1208          * Used for the title field in <a> tags.
1209          *
1210          * @return String the text, including any prefixes
1211          */
1212         public function getEscapedText() {
1213                 wfDeprecated( __METHOD__, '1.19' );
1214                 return htmlspecialchars( $this->getPrefixedText() );
1215         }
1216
1217         /**
1218          * Get a URL-encoded form of the subpage text
1219          *
1220          * @return String URL-encoded subpage name
1221          */
1222         public function getSubpageUrlForm() {
1223                 $text = $this->getSubpageText();
1224                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1225                 return( $text );
1226         }
1227
1228         /**
1229          * Get a URL-encoded title (not an actual URL) including interwiki
1230          *
1231          * @return String the URL-encoded form
1232          */
1233         public function getPrefixedURL() {
1234                 $s = $this->prefix( $this->mDbkeyform );
1235                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1236                 return $s;
1237         }
1238
1239         /**
1240          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1241          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1242          * second argument named variant. This was deprecated in favor
1243          * of passing an array of option with a "variant" key
1244          * Once $query2 is removed for good, this helper can be dropped
1245          * andthe wfArrayToCGI moved to getLocalURL();
1246          *
1247          * @since 1.19 (r105919)
1248          * @param $query
1249          * @param $query2 bool
1250          * @return String
1251          */
1252         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1253                 if( $query2 !== false ) {
1254                         wfDeprecated( "Title::get{Canonical,Full,Link,Local} method called with a second parameter is deprecated. Add your parameter to an array passed as the first parameter.", "1.19" );
1255                 }
1256                 if ( is_array( $query ) ) {
1257                         $query = wfArrayToCGI( $query );
1258                 }
1259                 if ( $query2 ) {
1260                         if ( is_string( $query2 ) ) {
1261                                 // $query2 is a string, we will consider this to be
1262                                 // a deprecated $variant argument and add it to the query
1263                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1264                         } else {
1265                                 $query2 = wfArrayToCGI( $query2 );
1266                         }
1267                         // If we have $query content add a & to it first
1268                         if ( $query ) {
1269                                 $query .= '&';
1270                         }
1271                         // Now append the queries together
1272                         $query .= $query2;
1273                 }
1274                 return $query;
1275         }
1276
1277         /**
1278          * Get a real URL referring to this title, with interwiki link and
1279          * fragment
1280          *
1281          * See getLocalURL for the arguments.
1282          *
1283          * @see self::getLocalURL
1284          * @return String the URL
1285          */
1286         public function getFullURL( $query = '', $query2 = false ) {
1287                 $query = self::fixUrlQueryArgs( $query, $query2 );
1288
1289                 # Hand off all the decisions on urls to getLocalURL
1290                 $url = $this->getLocalURL( $query );
1291
1292                 # Expand the url to make it a full url. Note that getLocalURL has the
1293                 # potential to output full urls for a variety of reasons, so we use
1294                 # wfExpandUrl instead of simply prepending $wgServer
1295                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1296
1297                 # Finally, add the fragment.
1298                 $url .= $this->getFragmentForURL();
1299
1300                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1301                 return $url;
1302         }
1303
1304         /**
1305          * Get a URL with no fragment or server name.  If this page is generated
1306          * with action=render, $wgServer is prepended.
1307          *
1308
1309          * @param $query string|array an optional query string,
1310          *   not used for interwiki     links. Can be specified as an associative array as well,
1311          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1312          *   Some query patterns will trigger various shorturl path replacements.
1313          * @param $query2 Mixed: An optional secondary query array. This one MUST
1314          *   be an array. If a string is passed it will be interpreted as a deprecated
1315          *   variant argument and urlencoded into a variant= argument.
1316          *   This second query argument will be added to the $query
1317          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1318          *   pair in the first parameter array instead.
1319          *
1320          * @return String the URL
1321          */
1322         public function getLocalURL( $query = '', $query2 = false ) {
1323                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1324
1325                 $query = self::fixUrlQueryArgs( $query, $query2 );
1326
1327                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1328                 if ( $interwiki ) {
1329                         $namespace = $this->getNsText();
1330                         if ( $namespace != '' ) {
1331                                 # Can this actually happen? Interwikis shouldn't be parsed.
1332                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1333                                 $namespace .= ':';
1334                         }
1335                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1336                         $url = wfAppendQuery( $url, $query );
1337                 } else {
1338                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1339                         if ( $query == '' ) {
1340                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1341                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1342                         } else {
1343                                 global $wgVariantArticlePath, $wgActionPaths;
1344                                 $url = false;
1345                                 $matches = array();
1346
1347                                 if ( !empty( $wgActionPaths ) &&
1348                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1349                                 {
1350                                         $action = urldecode( $matches[2] );
1351                                         if ( isset( $wgActionPaths[$action] ) ) {
1352                                                 $query = $matches[1];
1353                                                 if ( isset( $matches[4] ) ) {
1354                                                         $query .= $matches[4];
1355                                                 }
1356                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1357                                                 if ( $query != '' ) {
1358                                                         $url = wfAppendQuery( $url, $query );
1359                                                 }
1360                                         }
1361                                 }
1362
1363                                 if ( $url === false &&
1364                                         $wgVariantArticlePath &&
1365                                         $this->getPageLanguage()->hasVariants() &&
1366                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1367                                 {
1368                                         $variant = urldecode( $matches[1] );
1369                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1370                                                 // Only do the variant replacement if the given variant is a valid
1371                                                 // variant for the page's language.
1372                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1373                                                 $url = str_replace( '$1', $dbkey, $url );
1374                                         }
1375                                 }
1376
1377                                 if ( $url === false ) {
1378                                         if ( $query == '-' ) {
1379                                                 $query = '';
1380                                         }
1381                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1382                                 }
1383                         }
1384
1385                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1386
1387                         // @todo FIXME: This causes breakage in various places when we
1388                         // actually expected a local URL and end up with dupe prefixes.
1389                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1390                                 $url = $wgServer . $url;
1391                         }
1392                 }
1393                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1394                 return $url;
1395         }
1396
1397         /**
1398          * Get a URL that's the simplest URL that will be valid to link, locally,
1399          * to the current Title.  It includes the fragment, but does not include
1400          * the server unless action=render is used (or the link is external).  If
1401          * there's a fragment but the prefixed text is empty, we just return a link
1402          * to the fragment.
1403          *
1404          * The result obviously should not be URL-escaped, but does need to be
1405          * HTML-escaped if it's being output in HTML.
1406          *
1407          * See getLocalURL for the arguments.
1408          *
1409          * @see self::getLocalURL
1410          * @return String the URL
1411          */
1412         public function getLinkURL( $query = '', $query2 = false ) {
1413                 wfProfileIn( __METHOD__ );
1414                 if ( $this->isExternal() ) {
1415                         $ret = $this->getFullURL( $query, $query2 );
1416                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1417                         $ret = $this->getFragmentForURL();
1418                 } else {
1419                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1420                 }
1421                 wfProfileOut( __METHOD__ );
1422                 return $ret;
1423         }
1424
1425         /**
1426          * Get an HTML-escaped version of the URL form, suitable for
1427          * using in a link, without a server name or fragment
1428          *
1429          * See getLocalURL for the arguments.
1430          *
1431          * @see self::getLocalURL
1432          * @param $query string
1433          * @param $query2 bool|string
1434          * @return String the URL
1435          */
1436         public function escapeLocalURL( $query = '', $query2 = false ) {
1437                 wfDeprecated( __METHOD__, '1.19' );
1438                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1439         }
1440
1441         /**
1442          * Get an HTML-escaped version of the URL form, suitable for
1443          * using in a link, including the server name and fragment
1444          *
1445          * See getLocalURL for the arguments.
1446          *
1447          * @see self::getLocalURL
1448          * @return String the URL
1449          */
1450         public function escapeFullURL( $query = '', $query2 = false ) {
1451                 wfDeprecated( __METHOD__, '1.19' );
1452                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1453         }
1454
1455         /**
1456          * Get the URL form for an internal link.
1457          * - Used in various Squid-related code, in case we have a different
1458          * internal hostname for the server from the exposed one.
1459          *
1460          * This uses $wgInternalServer to qualify the path, or $wgServer
1461          * if $wgInternalServer is not set. If the server variable used is
1462          * protocol-relative, the URL will be expanded to http://
1463          *
1464          * See getLocalURL for the arguments.
1465          *
1466          * @see self::getLocalURL
1467          * @return String the URL
1468          */
1469         public function getInternalURL( $query = '', $query2 = false ) {
1470                 global $wgInternalServer, $wgServer;
1471                 $query = self::fixUrlQueryArgs( $query, $query2 );
1472                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1473                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1474                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1475                 return $url;
1476         }
1477
1478         /**
1479          * Get the URL for a canonical link, for use in things like IRC and
1480          * e-mail notifications. Uses $wgCanonicalServer and the
1481          * GetCanonicalURL hook.
1482          *
1483          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1484          *
1485          * See getLocalURL for the arguments.
1486          *
1487          * @see self::getLocalURL
1488          * @return string The URL
1489          * @since 1.18
1490          */
1491         public function getCanonicalURL( $query = '', $query2 = false ) {
1492                 $query = self::fixUrlQueryArgs( $query, $query2 );
1493                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1494                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1495                 return $url;
1496         }
1497
1498         /**
1499          * HTML-escaped version of getCanonicalURL()
1500          *
1501          * See getLocalURL for the arguments.
1502          *
1503          * @see self::getLocalURL
1504          * @since 1.18
1505          * @return string
1506          */
1507         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1508                 wfDeprecated( __METHOD__, '1.19' );
1509                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1510         }
1511
1512         /**
1513          * Get the edit URL for this Title
1514          *
1515          * @return String the URL, or a null string if this is an
1516          *  interwiki link
1517          */
1518         public function getEditURL() {
1519                 if ( $this->mInterwiki != '' ) {
1520                         return '';
1521                 }
1522                 $s = $this->getLocalURL( 'action=edit' );
1523
1524                 return $s;
1525         }
1526
1527         /**
1528          * Is $wgUser watching this page?
1529          *
1530          * @return Bool
1531          */
1532         public function userIsWatching() {
1533                 global $wgUser;
1534
1535                 if ( is_null( $this->mWatched ) ) {
1536                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1537                                 $this->mWatched = false;
1538                         } else {
1539                                 $this->mWatched = $wgUser->isWatched( $this );
1540                         }
1541                 }
1542                 return $this->mWatched;
1543         }
1544
1545         /**
1546          * Can $wgUser read this page?
1547          *
1548          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1549          * @return Bool
1550          * @todo fold these checks into userCan()
1551          */
1552         public function userCanRead() {
1553                 wfDeprecated( __METHOD__, '1.19' );
1554                 return $this->userCan( 'read' );
1555         }
1556
1557         /**
1558          * Can $user perform $action on this page?
1559          * This skips potentially expensive cascading permission checks
1560          * as well as avoids expensive error formatting
1561          *
1562          * Suitable for use for nonessential UI controls in common cases, but
1563          * _not_ for functional access control.
1564          *
1565          * May provide false positives, but should never provide a false negative.
1566          *
1567          * @param $action String action that permission needs to be checked for
1568          * @param $user User to check (since 1.19); $wgUser will be used if not
1569          *              provided.
1570          * @return Bool
1571          */
1572         public function quickUserCan( $action, $user = null ) {
1573                 return $this->userCan( $action, $user, false );
1574         }
1575
1576         /**
1577          * Can $user perform $action on this page?
1578          *
1579          * @param $action String action that permission needs to be checked for
1580          * @param $user User to check (since 1.19); $wgUser will be used if not
1581          *   provided.
1582          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1583          *   unnecessary queries.
1584          * @return Bool
1585          */
1586         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1587                 if ( !$user instanceof User ) {
1588                         global $wgUser;
1589                         $user = $wgUser;
1590                 }
1591                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1592         }
1593
1594         /**
1595          * Can $user perform $action on this page?
1596          *
1597          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1598          *
1599          * @param $action String action that permission needs to be checked for
1600          * @param $user User to check
1601          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1602          *   queries by skipping checks for cascading protections and user blocks.
1603          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1604          *   whose corresponding errors may be ignored.
1605          * @return Array of arguments to wfMsg to explain permissions problems.
1606          */
1607         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1608                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1609
1610                 // Remove the errors being ignored.
1611                 foreach ( $errors as $index => $error ) {
1612                         $error_key = is_array( $error ) ? $error[0] : $error;
1613
1614                         if ( in_array( $error_key, $ignoreErrors ) ) {
1615                                 unset( $errors[$index] );
1616                         }
1617                 }
1618
1619                 return $errors;
1620         }
1621
1622         /**
1623          * Permissions checks that fail most often, and which are easiest to test.
1624          *
1625          * @param $action String the action to check
1626          * @param $user User user to check
1627          * @param $errors Array list of current errors
1628          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1629          * @param $short Boolean short circuit on first error
1630          *
1631          * @return Array list of errors
1632          */
1633         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1634                 if ( $action == 'create' ) {
1635                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1636                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1637                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1638                         }
1639                 } elseif ( $action == 'move' ) {
1640                         if ( !$user->isAllowed( 'move-rootuserpages' )
1641                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1642                                 // Show user page-specific message only if the user can move other pages
1643                                 $errors[] = array( 'cant-move-user-page' );
1644                         }
1645
1646                         // Check if user is allowed to move files if it's a file
1647                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1648                                 $errors[] = array( 'movenotallowedfile' );
1649                         }
1650
1651                         if ( !$user->isAllowed( 'move' ) ) {
1652                                 // User can't move anything
1653                                 global $wgGroupPermissions;
1654                                 $userCanMove = false;
1655                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1656                                         $userCanMove = $wgGroupPermissions['user']['move'];
1657                                 }
1658                                 $autoconfirmedCanMove = false;
1659                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1660                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1661                                 }
1662                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1663                                         // custom message if logged-in users without any special rights can move
1664                                         $errors[] = array( 'movenologintext' );
1665                                 } else {
1666                                         $errors[] = array( 'movenotallowed' );
1667                                 }
1668                         }
1669                 } elseif ( $action == 'move-target' ) {
1670                         if ( !$user->isAllowed( 'move' ) ) {
1671                                 // User can't move anything
1672                                 $errors[] = array( 'movenotallowed' );
1673                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1674                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1675                                 // Show user page-specific message only if the user can move other pages
1676                                 $errors[] = array( 'cant-move-to-user-page' );
1677                         }
1678                 } elseif ( !$user->isAllowed( $action ) ) {
1679                         $errors[] = $this->missingPermissionError( $action, $short );
1680                 }
1681
1682                 return $errors;
1683         }
1684
1685         /**
1686          * Add the resulting error code to the errors array
1687          *
1688          * @param $errors Array list of current errors
1689          * @param $result Mixed result of errors
1690          *
1691          * @return Array list of errors
1692          */
1693         private function resultToError( $errors, $result ) {
1694                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1695                         // A single array representing an error
1696                         $errors[] = $result;
1697                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1698                         // A nested array representing multiple errors
1699                         $errors = array_merge( $errors, $result );
1700                 } elseif ( $result !== '' && is_string( $result ) ) {
1701                         // A string representing a message-id
1702                         $errors[] = array( $result );
1703                 } elseif ( $result === false ) {
1704                         // a generic "We don't want them to do that"
1705                         $errors[] = array( 'badaccess-group0' );
1706                 }
1707                 return $errors;
1708         }
1709
1710         /**
1711          * Check various permission hooks
1712          *
1713          * @param $action String the action to check
1714          * @param $user User user to check
1715          * @param $errors Array list of current errors
1716          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1717          * @param $short Boolean short circuit on first error
1718          *
1719          * @return Array list of errors
1720          */
1721         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1722                 // Use getUserPermissionsErrors instead
1723                 $result = '';
1724                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1725                         return $result ? array() : array( array( 'badaccess-group0' ) );
1726                 }
1727                 // Check getUserPermissionsErrors hook
1728                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1729                         $errors = $this->resultToError( $errors, $result );
1730                 }
1731                 // Check getUserPermissionsErrorsExpensive hook
1732                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1733                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1734                         $errors = $this->resultToError( $errors, $result );
1735                 }
1736
1737                 return $errors;
1738         }
1739
1740         /**
1741          * Check permissions on special pages & namespaces
1742          *
1743          * @param $action String the action to check
1744          * @param $user User user to check
1745          * @param $errors Array list of current errors
1746          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1747          * @param $short Boolean short circuit on first error
1748          *
1749          * @return Array list of errors
1750          */
1751         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1752                 # Only 'createaccount' and 'execute' can be performed on
1753                 # special pages, which don't actually exist in the DB.
1754                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1755                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1756                         $errors[] = array( 'ns-specialprotected' );
1757                 }
1758
1759                 # Check $wgNamespaceProtection for restricted namespaces
1760                 if ( $this->isNamespaceProtected( $user ) ) {
1761                         $ns = $this->mNamespace == NS_MAIN ?
1762                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1763                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1764                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1765                 }
1766
1767                 return $errors;
1768         }
1769
1770         /**
1771          * Check CSS/JS sub-page permissions
1772          *
1773          * @param $action String the action to check
1774          * @param $user User user to check
1775          * @param $errors Array list of current errors
1776          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1777          * @param $short Boolean short circuit on first error
1778          *
1779          * @return Array list of errors
1780          */
1781         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1782                 # Protect css/js subpages of user pages
1783                 # XXX: this might be better using restrictions
1784                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1785                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1786                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1787                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1788                                 $errors[] = array( 'customcssprotected' );
1789                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1790                                 $errors[] = array( 'customjsprotected' );
1791                         }
1792                 }
1793
1794                 return $errors;
1795         }
1796
1797         /**
1798          * Check against page_restrictions table requirements on this
1799          * page. The user must possess all required rights for this
1800          * action.
1801          *
1802          * @param $action String the action to check
1803          * @param $user User user to check
1804          * @param $errors Array list of current errors
1805          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1806          * @param $short Boolean short circuit on first error
1807          *
1808          * @return Array list of errors
1809          */
1810         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1811                 foreach ( $this->getRestrictions( $action ) as $right ) {
1812                         // Backwards compatibility, rewrite sysop -> protect
1813                         if ( $right == 'sysop' ) {
1814                                 $right = 'protect';
1815                         }
1816                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1817                                 // Users with 'editprotected' permission can edit protected pages
1818                                 // without cascading option turned on.
1819                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1820                                         || $this->mCascadeRestriction )
1821                                 {
1822                                         $errors[] = array( 'protectedpagetext', $right );
1823                                 }
1824                         }
1825                 }
1826
1827                 return $errors;
1828         }
1829
1830         /**
1831          * Check restrictions on cascading pages.
1832          *
1833          * @param $action String the action to check
1834          * @param $user User to check
1835          * @param $errors Array list of current errors
1836          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1837          * @param $short Boolean short circuit on first error
1838          *
1839          * @return Array list of errors
1840          */
1841         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1842                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1843                         # We /could/ use the protection level on the source page, but it's
1844                         # fairly ugly as we have to establish a precedence hierarchy for pages
1845                         # included by multiple cascade-protected pages. So just restrict
1846                         # it to people with 'protect' permission, as they could remove the
1847                         # protection anyway.
1848                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1849                         # Cascading protection depends on more than this page...
1850                         # Several cascading protected pages may include this page...
1851                         # Check each cascading level
1852                         # This is only for protection restrictions, not for all actions
1853                         if ( isset( $restrictions[$action] ) ) {
1854                                 foreach ( $restrictions[$action] as $right ) {
1855                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1856                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1857                                                 $pages = '';
1858                                                 foreach ( $cascadingSources as $page )
1859                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1860                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1861                                         }
1862                                 }
1863                         }
1864                 }
1865
1866                 return $errors;
1867         }
1868
1869         /**
1870          * Check action permissions not already checked in checkQuickPermissions
1871          *
1872          * @param $action String the action to check
1873          * @param $user User to check
1874          * @param $errors Array list of current errors
1875          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1876          * @param $short Boolean short circuit on first error
1877          *
1878          * @return Array list of errors
1879          */
1880         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1881                 global $wgDeleteRevisionsLimit, $wgLang;
1882
1883                 if ( $action == 'protect' ) {
1884                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1885                                 // If they can't edit, they shouldn't protect.
1886                                 $errors[] = array( 'protect-cantedit' );
1887                         }
1888                 } elseif ( $action == 'create' ) {
1889                         $title_protection = $this->getTitleProtection();
1890                         if( $title_protection ) {
1891                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1892                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1893                                 }
1894                                 if( $title_protection['pt_create_perm'] == '' ||
1895                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1896                                 {
1897                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1898                                 }
1899                         }
1900                 } elseif ( $action == 'move' ) {
1901                         // Check for immobile pages
1902                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1903                                 // Specific message for this case
1904                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1905                         } elseif ( !$this->isMovable() ) {
1906                                 // Less specific message for rarer cases
1907                                 $errors[] = array( 'immobile-source-page' );
1908                         }
1909                 } elseif ( $action == 'move-target' ) {
1910                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1911                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1912                         } elseif ( !$this->isMovable() ) {
1913                                 $errors[] = array( 'immobile-target-page' );
1914                         }
1915                 } elseif ( $action == 'delete' ) {
1916                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1917                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1918                         {
1919                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1920                         }
1921                 }
1922                 return $errors;
1923         }
1924
1925         /**
1926          * Check that the user isn't blocked from editting.
1927          *
1928          * @param $action String the action to check
1929          * @param $user User to check
1930          * @param $errors Array list of current errors
1931          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1932          * @param $short Boolean short circuit on first error
1933          *
1934          * @return Array list of errors
1935          */
1936         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1937                 // Account creation blocks handled at userlogin.
1938                 // Unblocking handled in SpecialUnblock
1939                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1940                         return $errors;
1941                 }
1942
1943                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1944
1945                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1946                         $errors[] = array( 'confirmedittext' );
1947                 }
1948
1949                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1950                         // Don't block the user from editing their own talk page unless they've been
1951                         // explicitly blocked from that too.
1952                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1953                         $block = $user->getBlock();
1954
1955                         // This is from OutputPage::blockedPage
1956                         // Copied at r23888 by werdna
1957
1958                         $id = $user->blockedBy();
1959                         $reason = $user->blockedFor();
1960                         if ( $reason == '' ) {
1961                                 $reason = wfMsg( 'blockednoreason' );
1962                         }
1963                         $ip = $user->getRequest()->getIP();
1964
1965                         if ( is_numeric( $id ) ) {
1966                                 $name = User::whoIs( $id );
1967                         } else {
1968                                 $name = $id;
1969                         }
1970
1971                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1972                         $blockid = $block->getId();
1973                         $blockExpiry = $block->getExpiry();
1974                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
1975                         if ( $blockExpiry == 'infinity' ) {
1976                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1977                         } else {
1978                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1979                         }
1980
1981                         $intended = strval( $block->getTarget() );
1982
1983                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1984                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1985                 }
1986
1987                 return $errors;
1988         }
1989
1990         /**
1991          * Check that the user is allowed to read this page.
1992          *
1993          * @param $action String the action to check
1994          * @param $user User to check
1995          * @param $errors Array list of current errors
1996          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1997          * @param $short Boolean short circuit on first error
1998          *
1999          * @return Array list of errors
2000          */
2001         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2002                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
2003                 static $useShortcut = null;
2004
2005                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2006                 if ( is_null( $useShortcut ) ) {
2007                         $useShortcut = true;
2008                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
2009                                 # Not a public wiki, so no shortcut
2010                                 $useShortcut = false;
2011                         } elseif ( !empty( $wgRevokePermissions ) ) {
2012                                 /**
2013                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2014                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2015                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2016                                  * reading is allowed.
2017                                  */
2018                                 foreach ( $wgRevokePermissions as $perms ) {
2019                                         if ( !empty( $perms['read'] ) ) {
2020                                                 # We might be removing the read right from the user, so no shortcut
2021                                                 $useShortcut = false;
2022                                                 break;
2023                                         }
2024                                 }
2025                         }
2026                 }
2027
2028                 $whitelisted = false;
2029                 if ( $useShortcut ) {
2030                         # Shortcut for public wikis, allows skipping quite a bit of code
2031                         $whitelisted = true;
2032                 } elseif ( $user->isAllowed( 'read' ) ) {
2033                         # If the user is allowed to read pages, he is allowed to read all pages
2034                         $whitelisted = true;
2035                 } elseif ( $this->isSpecial( 'Userlogin' )
2036                         || $this->isSpecial( 'ChangePassword' )
2037                         || $this->isSpecial( 'PasswordReset' )
2038                 ) {
2039                         # Always grant access to the login page.
2040                         # Even anons need to be able to log in.
2041                         $whitelisted = true;
2042                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2043                         # Time to check the whitelist
2044                         # Only do these checks is there's something to check against
2045                         $name = $this->getPrefixedText();
2046                         $dbName = $this->getPrefixedDBKey();
2047
2048                         // Check for explicit whitelisting with and without underscores
2049                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2050                                 $whitelisted = true;
2051                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2052                                 # Old settings might have the title prefixed with
2053                                 # a colon for main-namespace pages
2054                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2055                                         $whitelisted = true;
2056                                 }
2057                         } elseif ( $this->isSpecialPage() ) {
2058                                 # If it's a special page, ditch the subpage bit and check again
2059                                 $name = $this->getDBkey();
2060                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2061                                 if ( $name !== false ) {
2062                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2063                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2064                                                 $whitelisted = true;
2065                                         }
2066                                 }
2067                         }
2068                 }
2069
2070                 if ( !$whitelisted ) {
2071                         # If the title is not whitelisted, give extensions a chance to do so...
2072                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2073                         if ( !$whitelisted ) {
2074                                 $errors[] = $this->missingPermissionError( $action, $short );
2075                         }
2076                 }
2077
2078                 return $errors;
2079         }
2080
2081         /**
2082          * Get a description array when the user doesn't have the right to perform
2083          * $action (i.e. when User::isAllowed() returns false)
2084          *
2085          * @param $action String the action to check
2086          * @param $short Boolean short circuit on first error
2087          * @return Array list of errors
2088          */
2089         private function missingPermissionError( $action, $short ) {
2090                 // We avoid expensive display logic for quickUserCan's and such
2091                 if ( $short ) {
2092                         return array( 'badaccess-group0' );
2093                 }
2094
2095                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2096                         User::getGroupsWithPermission( $action ) );
2097
2098                 if ( count( $groups ) ) {
2099                         global $wgLang;
2100                         return array(
2101                                 'badaccess-groups',
2102                                 $wgLang->commaList( $groups ),
2103                                 count( $groups )
2104                         );
2105                 } else {
2106                         return array( 'badaccess-group0' );
2107                 }
2108         }
2109
2110         /**
2111          * Can $user perform $action on this page? This is an internal function,
2112          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2113          * checks on wfReadOnly() and blocks)
2114          *
2115          * @param $action String action that permission needs to be checked for
2116          * @param $user User to check
2117          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2118          * @param $short Bool Set this to true to stop after the first permission error.
2119          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2120          */
2121         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2122                 wfProfileIn( __METHOD__ );
2123
2124                 # Read has special handling
2125                 if ( $action == 'read' ) {
2126                         $checks = array(
2127                                 'checkPermissionHooks',
2128                                 'checkReadPermissions',
2129                         );
2130                 } else {
2131                         $checks = array(
2132                                 'checkQuickPermissions',
2133                                 'checkPermissionHooks',
2134                                 'checkSpecialsAndNSPermissions',
2135                                 'checkCSSandJSPermissions',
2136                                 'checkPageRestrictions',
2137                                 'checkCascadingSourcesRestrictions',
2138                                 'checkActionPermissions',
2139                                 'checkUserBlock'
2140                         );
2141                 }
2142
2143                 $errors = array();
2144                 while( count( $checks ) > 0 &&
2145                                 !( $short && count( $errors ) > 0 ) ) {
2146                         $method = array_shift( $checks );
2147                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2148                 }
2149
2150                 wfProfileOut( __METHOD__ );
2151                 return $errors;
2152         }
2153
2154         /**
2155          * Protect css subpages of user pages: can $wgUser edit
2156          * this page?
2157          *
2158          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2159          * @return Bool
2160          */
2161         public function userCanEditCssSubpage() {
2162                 global $wgUser;
2163                 wfDeprecated( __METHOD__, '1.19' );
2164                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2165                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2166         }
2167
2168         /**
2169          * Protect js subpages of user pages: can $wgUser edit
2170          * this page?
2171          *
2172          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2173          * @return Bool
2174          */
2175         public function userCanEditJsSubpage() {
2176                 global $wgUser;
2177                 wfDeprecated( __METHOD__, '1.19' );
2178                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2179                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2180         }
2181
2182         /**
2183          * Get a filtered list of all restriction types supported by this wiki.
2184          * @param bool $exists True to get all restriction types that apply to
2185          * titles that do exist, False for all restriction types that apply to
2186          * titles that do not exist
2187          * @return array
2188          */
2189         public static function getFilteredRestrictionTypes( $exists = true ) {
2190                 global $wgRestrictionTypes;
2191                 $types = $wgRestrictionTypes;
2192                 if ( $exists ) {
2193                         # Remove the create restriction for existing titles
2194                         $types = array_diff( $types, array( 'create' ) );
2195                 } else {
2196                         # Only the create and upload restrictions apply to non-existing titles
2197                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2198                 }
2199                 return $types;
2200         }
2201
2202         /**
2203          * Returns restriction types for the current Title
2204          *
2205          * @return array applicable restriction types
2206          */
2207         public function getRestrictionTypes() {
2208                 if ( $this->isSpecialPage() ) {
2209                         return array();
2210                 }
2211
2212                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2213
2214                 if ( $this->getNamespace() != NS_FILE ) {
2215                         # Remove the upload restriction for non-file titles
2216                         $types = array_diff( $types, array( 'upload' ) );
2217                 }
2218
2219                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2220
2221                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2222                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2223
2224                 return $types;
2225         }
2226
2227         /**
2228          * Is this title subject to title protection?
2229          * Title protection is the one applied against creation of such title.
2230          *
2231          * @return Mixed An associative array representing any existent title
2232          *   protection, or false if there's none.
2233          */
2234         private function getTitleProtection() {
2235                 // Can't protect pages in special namespaces
2236                 if ( $this->getNamespace() < 0 ) {
2237                         return false;
2238                 }
2239
2240                 // Can't protect pages that exist.
2241                 if ( $this->exists() ) {
2242                         return false;
2243                 }
2244
2245                 if ( !isset( $this->mTitleProtection ) ) {
2246                         $dbr = wfGetDB( DB_SLAVE );
2247                         $res = $dbr->select( 'protected_titles', '*',
2248                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2249                                 __METHOD__ );
2250
2251                         // fetchRow returns false if there are no rows.
2252                         $this->mTitleProtection = $dbr->fetchRow( $res );
2253                 }
2254                 return $this->mTitleProtection;
2255         }
2256
2257         /**
2258          * Update the title protection status
2259          *
2260          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2261          * @param $create_perm String Permission required for creation
2262          * @param $reason String Reason for protection
2263          * @param $expiry String Expiry timestamp
2264          * @return boolean true
2265          */
2266         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2267                 wfDeprecated( __METHOD__, '1.19' );
2268
2269                 global $wgUser;
2270
2271                 $limit = array( 'create' => $create_perm );
2272                 $expiry = array( 'create' => $expiry );
2273
2274                 $page = WikiPage::factory( $this );
2275                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2276
2277                 return $status->isOK();
2278         }
2279
2280         /**
2281          * Remove any title protection due to page existing
2282          */
2283         public function deleteTitleProtection() {
2284                 $dbw = wfGetDB( DB_MASTER );
2285
2286                 $dbw->delete(
2287                         'protected_titles',
2288                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2289                         __METHOD__
2290                 );
2291                 $this->mTitleProtection = false;
2292         }
2293
2294         /**
2295          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2296          *
2297          * @param $action String Action to check (default: edit)
2298          * @return Bool
2299          */
2300         public function isSemiProtected( $action = 'edit' ) {
2301                 if ( $this->exists() ) {
2302                         $restrictions = $this->getRestrictions( $action );
2303                         if ( count( $restrictions ) > 0 ) {
2304                                 foreach ( $restrictions as $restriction ) {
2305                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2306                                                 return false;
2307                                         }
2308                                 }
2309                         } else {
2310                                 # Not protected
2311                                 return false;
2312                         }
2313                         return true;
2314                 } else {
2315                         # If it doesn't exist, it can't be protected
2316                         return false;
2317                 }
2318         }
2319
2320         /**
2321          * Does the title correspond to a protected article?
2322          *
2323          * @param $action String the action the page is protected from,
2324          * by default checks all actions.
2325          * @return Bool
2326          */
2327         public function isProtected( $action = '' ) {
2328                 global $wgRestrictionLevels;
2329
2330                 $restrictionTypes = $this->getRestrictionTypes();
2331
2332                 # Special pages have inherent protection
2333                 if( $this->isSpecialPage() ) {
2334                         return true;
2335                 }
2336
2337                 # Check regular protection levels
2338                 foreach ( $restrictionTypes as $type ) {
2339                         if ( $action == $type || $action == '' ) {
2340                                 $r = $this->getRestrictions( $type );
2341                                 foreach ( $wgRestrictionLevels as $level ) {
2342                                         if ( in_array( $level, $r ) && $level != '' ) {
2343                                                 return true;
2344                                         }
2345                                 }
2346                         }
2347                 }
2348
2349                 return false;
2350         }
2351
2352         /**
2353          * Determines if $user is unable to edit this page because it has been protected
2354          * by $wgNamespaceProtection.
2355          *
2356          * @param $user User object to check permissions
2357          * @return Bool
2358          */
2359         public function isNamespaceProtected( User $user ) {
2360                 global $wgNamespaceProtection;
2361
2362                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2363                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2364                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2365                                         return true;
2366                                 }
2367                         }
2368                 }
2369                 return false;
2370         }
2371
2372         /**
2373          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2374          *
2375          * @return Bool If the page is subject to cascading restrictions.
2376          */
2377         public function isCascadeProtected() {
2378                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2379                 return ( $sources > 0 );
2380         }
2381
2382         /**
2383          * Cascading protection: Get the source of any cascading restrictions on this page.
2384          *
2385          * @param $getPages Bool Whether or not to retrieve the actual pages
2386          *        that the restrictions have come from.
2387          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2388          *     have come, false for none, or true if such restrictions exist, but $getPages
2389          *     was not set.  The restriction array is an array of each type, each of which
2390          *     contains a array of unique groups.
2391          */
2392         public function getCascadeProtectionSources( $getPages = true ) {
2393                 global $wgContLang;
2394                 $pagerestrictions = array();
2395
2396                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2397                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2398                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2399                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2400                 }
2401
2402                 wfProfileIn( __METHOD__ );
2403
2404                 $dbr = wfGetDB( DB_SLAVE );
2405
2406                 if ( $this->getNamespace() == NS_FILE ) {
2407                         $tables = array( 'imagelinks', 'page_restrictions' );
2408                         $where_clauses = array(
2409                                 'il_to' => $this->getDBkey(),
2410                                 'il_from=pr_page',
2411                                 'pr_cascade' => 1
2412                         );
2413                 } else {
2414                         $tables = array( 'templatelinks', 'page_restrictions' );
2415                         $where_clauses = array(
2416                                 'tl_namespace' => $this->getNamespace(),
2417                                 'tl_title' => $this->getDBkey(),
2418                                 'tl_from=pr_page',
2419                                 'pr_cascade' => 1
2420                         );
2421                 }
2422
2423                 if ( $getPages ) {
2424                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2425                                                    'pr_expiry', 'pr_type', 'pr_level' );
2426                         $where_clauses[] = 'page_id=pr_page';
2427                         $tables[] = 'page';
2428                 } else {
2429                         $cols = array( 'pr_expiry' );
2430                 }
2431
2432                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2433
2434                 $sources = $getPages ? array() : false;
2435                 $now = wfTimestampNow();
2436                 $purgeExpired = false;
2437
2438                 foreach ( $res as $row ) {
2439                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2440                         if ( $expiry > $now ) {
2441                                 if ( $getPages ) {
2442                                         $page_id = $row->pr_page;
2443                                         $page_ns = $row->page_namespace;
2444                                         $page_title = $row->page_title;
2445                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2446                                         # Add groups needed for each restriction type if its not already there
2447                                         # Make sure this restriction type still exists
2448
2449                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2450                                                 $pagerestrictions[$row->pr_type] = array();
2451                                         }
2452
2453                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2454                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2455                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2456                                         }
2457                                 } else {
2458                                         $sources = true;
2459                                 }
2460                         } else {
2461                                 // Trigger lazy purge of expired restrictions from the db
2462                                 $purgeExpired = true;
2463                         }
2464                 }
2465                 if ( $purgeExpired ) {
2466                         Title::purgeExpiredRestrictions();
2467                 }
2468
2469                 if ( $getPages ) {
2470                         $this->mCascadeSources = $sources;
2471                         $this->mCascadingRestrictions = $pagerestrictions;
2472                 } else {
2473                         $this->mHasCascadingRestrictions = $sources;
2474                 }
2475
2476                 wfProfileOut( __METHOD__ );
2477                 return array( $sources, $pagerestrictions );
2478         }
2479
2480         /**
2481          * Accessor/initialisation for mRestrictions
2482          *
2483          * @param $action String action that permission needs to be checked for
2484          * @return Array of Strings the array of groups allowed to edit this article
2485          */
2486         public function getRestrictions( $action ) {
2487                 if ( !$this->mRestrictionsLoaded ) {
2488                         $this->loadRestrictions();
2489                 }
2490                 return isset( $this->mRestrictions[$action] )
2491                                 ? $this->mRestrictions[$action]
2492                                 : array();
2493         }
2494
2495         /**
2496          * Get the expiry time for the restriction against a given action
2497          *
2498          * @param $action
2499          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2500          *     or not protected at all, or false if the action is not recognised.
2501          */
2502         public function getRestrictionExpiry( $action ) {
2503                 if ( !$this->mRestrictionsLoaded ) {
2504                         $this->loadRestrictions();
2505                 }
2506                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2507         }
2508
2509         /**
2510          * Returns cascading restrictions for the current article
2511          *
2512          * @return Boolean
2513          */
2514         function areRestrictionsCascading() {
2515                 if ( !$this->mRestrictionsLoaded ) {
2516                         $this->loadRestrictions();
2517                 }
2518
2519                 return $this->mCascadeRestriction;
2520         }
2521
2522         /**
2523          * Loads a string into mRestrictions array
2524          *
2525          * @param $res Resource restrictions as an SQL result.
2526          * @param $oldFashionedRestrictions String comma-separated list of page
2527          *        restrictions from page table (pre 1.10)
2528          */
2529         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2530                 $rows = array();
2531
2532                 foreach ( $res as $row ) {
2533                         $rows[] = $row;
2534                 }
2535
2536                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2537         }
2538
2539         /**
2540          * Compiles list of active page restrictions from both page table (pre 1.10)
2541          * and page_restrictions table for this existing page.
2542          * Public for usage by LiquidThreads.
2543          *
2544          * @param $rows array of db result objects
2545          * @param $oldFashionedRestrictions string comma-separated list of page
2546          *        restrictions from page table (pre 1.10)
2547          */
2548         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2549                 global $wgContLang;
2550                 $dbr = wfGetDB( DB_SLAVE );
2551
2552                 $restrictionTypes = $this->getRestrictionTypes();
2553
2554                 foreach ( $restrictionTypes as $type ) {
2555                         $this->mRestrictions[$type] = array();
2556                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2557                 }
2558
2559                 $this->mCascadeRestriction = false;
2560
2561                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2562
2563                 if ( $oldFashionedRestrictions === null ) {
2564                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2565                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2566                 }
2567
2568                 if ( $oldFashionedRestrictions != '' ) {
2569
2570                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2571                                 $temp = explode( '=', trim( $restrict ) );
2572                                 if ( count( $temp ) == 1 ) {
2573                                         // old old format should be treated as edit/move restriction
2574                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2575                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2576                                 } else {
2577                                         $restriction = trim( $temp[1] );
2578                                         if( $restriction != '' ) { //some old entries are empty
2579                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2580                                         }
2581                                 }
2582                         }
2583
2584                         $this->mOldRestrictions = true;
2585
2586                 }
2587
2588                 if ( count( $rows ) ) {
2589                         # Current system - load second to make them override.
2590                         $now = wfTimestampNow();
2591                         $purgeExpired = false;
2592
2593                         # Cycle through all the restrictions.
2594                         foreach ( $rows as $row ) {
2595
2596                                 // Don't take care of restrictions types that aren't allowed
2597                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2598                                         continue;
2599
2600                                 // This code should be refactored, now that it's being used more generally,
2601                                 // But I don't really see any harm in leaving it in Block for now -werdna
2602                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2603
2604                                 // Only apply the restrictions if they haven't expired!
2605                                 if ( !$expiry || $expiry > $now ) {
2606                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2607                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2608
2609                                         $this->mCascadeRestriction |= $row->pr_cascade;
2610                                 } else {
2611                                         // Trigger a lazy purge of expired restrictions
2612                                         $purgeExpired = true;
2613                                 }
2614                         }
2615
2616                         if ( $purgeExpired ) {
2617                                 Title::purgeExpiredRestrictions();
2618                         }
2619                 }
2620
2621                 $this->mRestrictionsLoaded = true;
2622         }
2623
2624         /**
2625          * Load restrictions from the page_restrictions table
2626          *
2627          * @param $oldFashionedRestrictions String comma-separated list of page
2628          *        restrictions from page table (pre 1.10)
2629          */
2630         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2631                 global $wgContLang;
2632                 if ( !$this->mRestrictionsLoaded ) {
2633                         if ( $this->exists() ) {
2634                                 $dbr = wfGetDB( DB_SLAVE );
2635
2636                                 $res = $dbr->select(
2637                                         'page_restrictions',
2638                                         '*',
2639                                         array( 'pr_page' => $this->getArticleID() ),
2640                                         __METHOD__
2641                                 );
2642
2643                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2644                         } else {
2645                                 $title_protection = $this->getTitleProtection();
2646
2647                                 if ( $title_protection ) {
2648                                         $now = wfTimestampNow();
2649                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2650
2651                                         if ( !$expiry || $expiry > $now ) {
2652                                                 // Apply the restrictions
2653                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2654                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2655                                         } else { // Get rid of the old restrictions
2656                                                 Title::purgeExpiredRestrictions();
2657                                                 $this->mTitleProtection = false;
2658                                         }
2659                                 } else {
2660                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2661                                 }
2662                                 $this->mRestrictionsLoaded = true;
2663                         }
2664                 }
2665         }
2666
2667         /**
2668          * Flush the protection cache in this object and force reload from the database.
2669          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2670          */
2671         public function flushRestrictions() {
2672                 $this->mRestrictionsLoaded = false;
2673                 $this->mTitleProtection = null;
2674         }
2675
2676         /**
2677          * Purge expired restrictions from the page_restrictions table
2678          */
2679         static function purgeExpiredRestrictions() {
2680                 $dbw = wfGetDB( DB_MASTER );
2681                 $dbw->delete(
2682                         'page_restrictions',
2683                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2684                         __METHOD__
2685                 );
2686
2687                 $dbw->delete(
2688                         'protected_titles',
2689                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2690                         __METHOD__
2691                 );
2692         }
2693
2694         /**
2695          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2696          *
2697          * @return Bool
2698          */
2699         public function hasSubpages() {
2700                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2701                         # Duh
2702                         return false;
2703                 }
2704
2705                 # We dynamically add a member variable for the purpose of this method
2706                 # alone to cache the result.  There's no point in having it hanging
2707                 # around uninitialized in every Title object; therefore we only add it
2708                 # if needed and don't declare it statically.
2709                 if ( isset( $this->mHasSubpages ) ) {
2710                         return $this->mHasSubpages;
2711                 }
2712
2713                 $subpages = $this->getSubpages( 1 );
2714                 if ( $subpages instanceof TitleArray ) {
2715                         return $this->mHasSubpages = (bool)$subpages->count();
2716                 }
2717                 return $this->mHasSubpages = false;
2718         }
2719
2720         /**
2721          * Get all subpages of this page.
2722          *
2723          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2724          * @return mixed TitleArray, or empty array if this page's namespace
2725          *  doesn't allow subpages
2726          */
2727         public function getSubpages( $limit = -1 ) {
2728                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2729                         return array();
2730                 }
2731
2732                 $dbr = wfGetDB( DB_SLAVE );
2733                 $conds['page_namespace'] = $this->getNamespace();
2734                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2735                 $options = array();
2736                 if ( $limit > -1 ) {
2737                         $options['LIMIT'] = $limit;
2738                 }
2739                 return $this->mSubpages = TitleArray::newFromResult(
2740                         $dbr->select( 'page',
2741                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2742                                 $conds,
2743                                 __METHOD__,
2744                                 $options
2745                         )
2746                 );
2747         }
2748
2749         /**
2750          * Is there a version of this page in the deletion archive?
2751          *
2752          * @return Int the number of archived revisions
2753          */
2754         public function isDeleted() {
2755                 if ( $this->getNamespace() < 0 ) {
2756                         $n = 0;
2757                 } else {
2758                         $dbr = wfGetDB( DB_SLAVE );
2759
2760                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2761                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2762                                 __METHOD__
2763                         );
2764                         if ( $this->getNamespace() == NS_FILE ) {
2765                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2766                                         array( 'fa_name' => $this->getDBkey() ),
2767                                         __METHOD__
2768                                 );
2769                         }
2770                 }
2771                 return (int)$n;
2772         }
2773
2774         /**
2775          * Is there a version of this page in the deletion archive?
2776          *
2777          * @return Boolean
2778          */
2779         public function isDeletedQuick() {
2780                 if ( $this->getNamespace() < 0 ) {
2781                         return false;
2782                 }
2783                 $dbr = wfGetDB( DB_SLAVE );
2784                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2785                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2786                         __METHOD__
2787                 );
2788                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2789                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2790                                 array( 'fa_name' => $this->getDBkey() ),
2791                                 __METHOD__
2792                         );
2793                 }
2794                 return $deleted;
2795         }
2796
2797         /**
2798          * Get the article ID for this Title from the link cache,
2799          * adding it if necessary
2800          *
2801          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2802          *  for update
2803          * @return Int the ID
2804          */
2805         public function getArticleID( $flags = 0 ) {
2806                 if ( $this->getNamespace() < 0 ) {
2807                         return $this->mArticleID = 0;
2808                 }
2809                 $linkCache = LinkCache::singleton();
2810                 if ( $flags & self::GAID_FOR_UPDATE ) {
2811                         $oldUpdate = $linkCache->forUpdate( true );
2812                         $linkCache->clearLink( $this );
2813                         $this->mArticleID = $linkCache->addLinkObj( $this );
2814                         $linkCache->forUpdate( $oldUpdate );
2815                 } else {
2816                         if ( -1 == $this->mArticleID ) {
2817                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2818                         }
2819                 }
2820                 return $this->mArticleID;
2821         }
2822
2823         /**
2824          * Is this an article that is a redirect page?
2825          * Uses link cache, adding it if necessary
2826          *
2827          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2828          * @return Bool
2829          */
2830         public function isRedirect( $flags = 0 ) {
2831                 if ( !is_null( $this->mRedirect ) ) {
2832                         return $this->mRedirect;
2833                 }
2834                 # Calling getArticleID() loads the field from cache as needed
2835                 if ( !$this->getArticleID( $flags ) ) {
2836                         return $this->mRedirect = false;
2837                 }
2838
2839                 $linkCache = LinkCache::singleton();
2840                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2841                 assert( $cached !== null ); # assert the assumption that the cache actually knows about this title #XXX breaks stuff #TODO: use exception
2842
2843                 $this->mRedirect = (bool)$cached;
2844
2845                 return $this->mRedirect;
2846         }
2847
2848         /**
2849          * What is the length of this page?
2850          * Uses link cache, adding it if necessary
2851          *
2852          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2853          * @return Int
2854          */
2855         public function getLength( $flags = 0 ) {
2856                 if ( $this->mLength != -1 ) {
2857                         return $this->mLength;
2858                 }
2859                 # Calling getArticleID() loads the field from cache as needed
2860                 if ( !$this->getArticleID( $flags ) ) {
2861                         return $this->mLength = 0;
2862                 }
2863                 $linkCache = LinkCache::singleton();
2864                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
2865                 assert( $cached !== null ); # assert the assumption that the cache actually knows about this title #TODO: use exception
2866
2867                 $this->mLength = intval( $cached );
2868
2869                 return $this->mLength;
2870         }
2871
2872         /**
2873          * What is the page_latest field for this page?
2874          *
2875          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2876          * @return Int or 0 if the page doesn't exist
2877          */
2878         public function getLatestRevID( $flags = 0 ) {
2879                 if ( $this->mLatestID !== false ) {
2880                         return intval( $this->mLatestID );
2881                 }
2882                 # Calling getArticleID() loads the field from cache as needed
2883                 if ( !$this->getArticleID( $flags ) ) {
2884                         return $this->mLatestID = 0;
2885                 }
2886                 $linkCache = LinkCache::singleton();
2887                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
2888                 assert( $cached !== null ); # assert the assumption that the cache actually knows about this title #TODO: use exception
2889
2890                 $this->mLatestID = intval( $cached );
2891
2892                 return $this->mLatestID;
2893         }
2894
2895         /**
2896          * This clears some fields in this object, and clears any associated
2897          * keys in the "bad links" section of the link cache.
2898          *
2899          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2900          * loading of the new page_id. It's also called from
2901          * WikiPage::doDeleteArticle()
2902          *
2903          * @param $newid Int the new Article ID
2904          */
2905         public function resetArticleID( $newid ) {
2906                 $linkCache = LinkCache::singleton();
2907                 $linkCache->clearLink( $this );
2908
2909                 if ( $newid === false ) {
2910                         $this->mArticleID = -1;
2911                 } else {
2912                         $this->mArticleID = intval( $newid );
2913                 }
2914                 $this->mRestrictionsLoaded = false;
2915                 $this->mRestrictions = array();
2916                 $this->mRedirect = null;
2917                 $this->mLength = -1;
2918                 $this->mLatestID = false;
2919                 $this->mContentModel = false;
2920                 $this->mEstimateRevisions = null;
2921         }
2922
2923         /**
2924          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2925          *
2926          * @param $text String containing title to capitalize
2927          * @param $ns int namespace index, defaults to NS_MAIN
2928          * @return String containing capitalized title
2929          */
2930         public static function capitalize( $text, $ns = NS_MAIN ) {
2931                 global $wgContLang;
2932
2933                 if ( MWNamespace::isCapitalized( $ns ) ) {
2934                         return $wgContLang->ucfirst( $text );
2935                 } else {
2936                         return $text;
2937                 }
2938         }
2939
2940         /**
2941          * Secure and split - main initialisation function for this object
2942          *
2943          * Assumes that mDbkeyform has been set, and is urldecoded
2944          * and uses underscores, but not otherwise munged.  This function
2945          * removes illegal characters, splits off the interwiki and
2946          * namespace prefixes, sets the other forms, and canonicalizes
2947          * everything.
2948          *
2949          * @return Bool true on success
2950          */
2951         private function secureAndSplit() {
2952                 global $wgContLang, $wgLocalInterwiki;
2953
2954                 # Initialisation
2955                 $this->mInterwiki = $this->mFragment = '';
2956                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2957
2958                 $dbkey = $this->mDbkeyform;
2959
2960                 # Strip Unicode bidi override characters.
2961                 # Sometimes they slip into cut-n-pasted page titles, where the
2962                 # override chars get included in list displays.
2963                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2964
2965                 # Clean up whitespace
2966                 # Note: use of the /u option on preg_replace here will cause
2967                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2968                 # conveniently disabling them.
2969                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2970                 $dbkey = trim( $dbkey, '_' );
2971
2972                 if ( $dbkey == '' ) {
2973                         return false;
2974                 }
2975
2976                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2977                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2978                         return false;
2979                 }
2980
2981                 $this->mDbkeyform = $dbkey;
2982
2983                 # Initial colon indicates main namespace rather than specified default
2984                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2985                 if ( ':' == $dbkey[0] ) {
2986                         $this->mNamespace = NS_MAIN;
2987                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2988                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2989                 }
2990
2991                 # Namespace or interwiki prefix
2992                 $firstPass = true;
2993                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2994                 do {
2995                         $m = array();
2996                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2997                                 $p = $m[1];
2998                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2999                                         # Ordinary namespace
3000                                         $dbkey = $m[2];
3001                                         $this->mNamespace = $ns;
3002                                         # For Talk:X pages, check if X has a "namespace" prefix
3003                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3004                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3005                                                         # Disallow Talk:File:x type titles...
3006                                                         return false;
3007                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3008                                                         # Disallow Talk:Interwiki:x type titles...
3009                                                         return false;
3010                                                 }
3011                                         }
3012                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3013                                         if ( !$firstPass ) {
3014                                                 # Can't make a local interwiki link to an interwiki link.
3015                                                 # That's just crazy!
3016                                                 return false;
3017                                         }
3018
3019                                         # Interwiki link
3020                                         $dbkey = $m[2];
3021                                         $this->mInterwiki = $wgContLang->lc( $p );
3022
3023                                         # Redundant interwiki prefix to the local wiki
3024                                         if ( $wgLocalInterwiki !== false
3025                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3026                                         {
3027                                                 if ( $dbkey == '' ) {
3028                                                         # Can't have an empty self-link
3029                                                         return false;
3030                                                 }
3031                                                 $this->mInterwiki = '';
3032                                                 $firstPass = false;
3033                                                 # Do another namespace split...
3034                                                 continue;
3035                                         }
3036
3037                                         # If there's an initial colon after the interwiki, that also
3038                                         # resets the default namespace
3039                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3040                                                 $this->mNamespace = NS_MAIN;
3041                                                 $dbkey = substr( $dbkey, 1 );
3042                                         }
3043                                 }
3044                                 # If there's no recognized interwiki or namespace,
3045                                 # then let the colon expression be part of the title.
3046                         }
3047                         break;
3048                 } while ( true );
3049
3050                 # We already know that some pages won't be in the database!
3051                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3052                         $this->mArticleID = 0;
3053                 }
3054                 $fragment = strstr( $dbkey, '#' );
3055                 if ( false !== $fragment ) {
3056                         $this->setFragment( $fragment );
3057                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3058                         # remove whitespace again: prevents "Foo_bar_#"
3059                         # becoming "Foo_bar_"
3060                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3061                 }
3062
3063                 # Reject illegal characters.
3064                 $rxTc = self::getTitleInvalidRegex();
3065                 if ( preg_match( $rxTc, $dbkey ) ) {
3066                         return false;
3067                 }
3068
3069                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3070                 # reachable due to the way web browsers deal with 'relative' URLs.
3071                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3072                 if ( strpos( $dbkey, '.' ) !== false &&
3073                          ( $dbkey === '.' || $dbkey === '..' ||
3074                            strpos( $dbkey, './' ) === 0  ||
3075                            strpos( $dbkey, '../' ) === 0 ||
3076                            strpos( $dbkey, '/./' ) !== false ||
3077                            strpos( $dbkey, '/../' ) !== false  ||
3078                            substr( $dbkey, -2 ) == '/.' ||
3079                            substr( $dbkey, -3 ) == '/..' ) )
3080                 {
3081                         return false;
3082                 }
3083
3084                 # Magic tilde sequences? Nu-uh!
3085                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3086                         return false;
3087                 }
3088
3089                 # Limit the size of titles to 255 bytes. This is typically the size of the
3090                 # underlying database field. We make an exception for special pages, which
3091                 # don't need to be stored in the database, and may edge over 255 bytes due
3092                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3093                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3094                   strlen( $dbkey ) > 512 )
3095                 {
3096                         return false;
3097                 }
3098
3099                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3100                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3101                 # other site might be case-sensitive.
3102                 $this->mUserCaseDBKey = $dbkey;
3103                 if ( $this->mInterwiki == '' ) {
3104                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3105                 }
3106
3107                 # Can't make a link to a namespace alone... "empty" local links can only be
3108                 # self-links with a fragment identifier.
3109                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3110                         return false;
3111                 }
3112
3113                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3114                 // IP names are not allowed for accounts, and can only be referring to
3115                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3116                 // there are numerous ways to present the same IP. Having sp:contribs scan
3117                 // them all is silly and having some show the edits and others not is
3118                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3119                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3120                         ? IP::sanitizeIP( $dbkey )
3121                         : $dbkey;
3122
3123                 // Any remaining initial :s are illegal.
3124                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3125                         return false;
3126                 }
3127
3128                 # Fill fields
3129                 $this->mDbkeyform = $dbkey;
3130                 $this->mUrlform = wfUrlencode( $dbkey );
3131
3132                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3133
3134                 return true;
3135         }
3136
3137         /**
3138          * Get an array of Title objects linking to this Title
3139          * Also stores the IDs in the link cache.
3140          *
3141          * WARNING: do not use this function on arbitrary user-supplied titles!
3142          * On heavily-used templates it will max out the memory.
3143          *
3144          * @param $options Array: may be FOR UPDATE
3145          * @param $table String: table name
3146          * @param $prefix String: fields prefix
3147          * @return Array of Title objects linking here
3148          */
3149         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3150                 if ( count( $options ) > 0 ) {
3151                         $db = wfGetDB( DB_MASTER );
3152                 } else {
3153                         $db = wfGetDB( DB_SLAVE );
3154                 }
3155
3156                 $res = $db->select(
3157                         array( 'page', $table ),
3158                         self::getSelectFields(),
3159                         array(
3160                                 "{$prefix}_from=page_id",
3161                                 "{$prefix}_namespace" => $this->getNamespace(),
3162                                 "{$prefix}_title"     => $this->getDBkey() ),
3163                         __METHOD__,
3164                         $options
3165                 );
3166
3167                 $retVal = array();
3168                 if ( $res->numRows() ) {
3169                         $linkCache = LinkCache::singleton();
3170                         foreach ( $res as $row ) {
3171                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3172                                 if ( $titleObj ) {
3173                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3174                                         $retVal[] = $titleObj;
3175                                 }
3176                         }
3177                 }
3178                 return $retVal;
3179         }
3180
3181         /**
3182          * Get an array of Title objects using this Title as a template
3183          * Also stores the IDs in the link cache.
3184          *
3185          * WARNING: do not use this function on arbitrary user-supplied titles!
3186          * On heavily-used templates it will max out the memory.
3187          *
3188          * @param $options Array: may be FOR UPDATE
3189          * @return Array of Title the Title objects linking here
3190          */
3191         public function getTemplateLinksTo( $options = array() ) {
3192                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3193         }
3194
3195         /**
3196          * Get an array of Title objects linked from this Title
3197          * Also stores the IDs in the link cache.
3198          *
3199          * WARNING: do not use this function on arbitrary user-supplied titles!
3200          * On heavily-used templates it will max out the memory.
3201          *
3202          * @param $options Array: may be FOR UPDATE
3203          * @param $table String: table name
3204          * @param $prefix String: fields prefix
3205          * @return Array of Title objects linking here
3206          */
3207         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3208                 global $wgContentHandlerUseDB;
3209
3210                 $id = $this->getArticleID();
3211
3212                 # If the page doesn't exist; there can't be any link from this page
3213                 if ( !$id ) {
3214                         return array();
3215                 }
3216
3217                 if ( count( $options ) > 0 ) {
3218                         $db = wfGetDB( DB_MASTER );
3219                 } else {
3220                         $db = wfGetDB( DB_SLAVE );
3221                 }
3222
3223                 $namespaceFiled = "{$prefix}_namespace";
3224                 $titleField = "{$prefix}_title";
3225
3226                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3227                 if ( $wgContentHandlerUseDB ) $fields[] = 'page_content_model';
3228
3229                 $res = $db->select(
3230                         array( $table, 'page' ),
3231                         $fields,
3232                         array( "{$prefix}_from" => $id ),
3233                         __METHOD__,
3234                         $options,
3235                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3236                 );
3237
3238                 $retVal = array();
3239                 if ( $res->numRows() ) {
3240                         $linkCache = LinkCache::singleton();
3241                         foreach ( $res as $row ) {
3242                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3243                                 if ( $titleObj ) {
3244                                         if ( $row->page_id ) {
3245                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3246                                         } else {
3247                                                 $linkCache->addBadLinkObj( $titleObj );
3248                                         }
3249                                         $retVal[] = $titleObj;
3250                                 }
3251                         }
3252                 }
3253                 return $retVal;
3254         }
3255
3256         /**
3257          * Get an array of Title objects used on this Title as a template
3258          * Also stores the IDs in the link cache.
3259          *
3260          * WARNING: do not use this function on arbitrary user-supplied titles!
3261          * On heavily-used templates it will max out the memory.
3262          *
3263          * @param $options Array: may be FOR UPDATE
3264          * @return Array of Title the Title objects used here
3265          */
3266         public function getTemplateLinksFrom( $options = array() ) {
3267                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3268         }
3269
3270         /**
3271          * Get an array of Title objects referring to non-existent articles linked from this page
3272          *
3273          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3274          * @return Array of Title the Title objects
3275          */
3276         public function getBrokenLinksFrom() {
3277                 if ( $this->getArticleID() == 0 ) {
3278                         # All links from article ID 0 are false positives
3279                         return array();
3280                 }
3281
3282                 $dbr = wfGetDB( DB_SLAVE );
3283                 $res = $dbr->select(
3284                         array( 'page', 'pagelinks' ),
3285                         array( 'pl_namespace', 'pl_title' ),
3286                         array(
3287                                 'pl_from' => $this->getArticleID(),
3288                                 'page_namespace IS NULL'
3289                         ),
3290                         __METHOD__, array(),
3291                         array(
3292                                 'page' => array(
3293                                         'LEFT JOIN',
3294                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3295                                 )
3296                         )
3297                 );
3298
3299                 $retVal = array();
3300                 foreach ( $res as $row ) {
3301                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3302                 }
3303                 return $retVal;
3304         }
3305
3306
3307         /**
3308          * Get a list of URLs to purge from the Squid cache when this
3309          * page changes
3310          *
3311          * @return Array of String the URLs
3312          */
3313         public function getSquidURLs() {
3314                 global $wgContLang;
3315
3316                 $urls = array(
3317                         $this->getInternalURL(),
3318                         $this->getInternalURL( 'action=history' )
3319                 );
3320
3321                 // purge variant urls as well
3322                 if ( $wgContLang->hasVariants() ) {
3323                         $variants = $wgContLang->getVariants();
3324                         foreach ( $variants as $vCode ) {
3325                                 $urls[] = $this->getInternalURL( '', $vCode );
3326                         }
3327                 }
3328
3329                 return $urls;
3330         }
3331
3332         /**
3333          * Purge all applicable Squid URLs
3334          */
3335         public function purgeSquid() {
3336                 global $wgUseSquid;
3337                 if ( $wgUseSquid ) {
3338                         $urls = $this->getSquidURLs();
3339                         $u = new SquidUpdate( $urls );
3340                         $u->doUpdate();
3341                 }
3342         }
3343
3344         /**
3345          * Move this page without authentication
3346          *
3347          * @param $nt Title the new page Title
3348          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3349          */
3350         public function moveNoAuth( &$nt ) {
3351                 return $this->moveTo( $nt, false );
3352         }
3353
3354         /**
3355          * Check whether a given move operation would be valid.
3356          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3357          *
3358          * @param $nt Title the new title
3359          * @param $auth Bool indicates whether $wgUser's permissions
3360          *  should be checked
3361          * @param $reason String is the log summary of the move, used for spam checking
3362          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3363          */
3364         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3365                 global $wgUser;
3366
3367                 $errors = array();
3368                 if ( !$nt ) {
3369                         // Normally we'd add this to $errors, but we'll get
3370                         // lots of syntax errors if $nt is not an object
3371                         return array( array( 'badtitletext' ) );
3372                 }
3373                 if ( $this->equals( $nt ) ) {
3374                         $errors[] = array( 'selfmove' );
3375                 }
3376                 if ( !$this->isMovable() ) {
3377                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3378                 }
3379                 if ( $nt->getInterwiki() != '' ) {
3380                         $errors[] = array( 'immobile-target-namespace-iw' );
3381                 }
3382                 if ( !$nt->isMovable() ) {
3383                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3384                 }
3385
3386                 $oldid = $this->getArticleID();
3387                 $newid = $nt->getArticleID();
3388
3389                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3390                         $errors[] = array( 'articleexists' );
3391                 }
3392                 if ( ( $this->getDBkey() == '' ) ||
3393                          ( !$oldid ) ||
3394                          ( $nt->getDBkey() == '' ) ) {
3395                         $errors[] = array( 'badarticleerror' );
3396                 }
3397
3398                 // Image-specific checks
3399                 if ( $this->getNamespace() == NS_FILE ) {
3400                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3401                 }
3402
3403                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3404                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3405                 }
3406
3407                 if ( $auth ) {
3408                         $errors = wfMergeErrorArrays( $errors,
3409                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3410                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3411                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3412                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3413                 }
3414
3415                 $match = EditPage::matchSummarySpamRegex( $reason );
3416                 if ( $match !== false ) {
3417                         // This is kind of lame, won't display nice
3418                         $errors[] = array( 'spamprotectiontext' );
3419                 }
3420
3421                 $err = null;
3422                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3423                         $errors[] = array( 'hookaborted', $err );
3424                 }
3425
3426                 # The move is allowed only if (1) the target doesn't exist, or
3427                 # (2) the target is a redirect to the source, and has no history
3428                 # (so we can undo bad moves right after they're done).
3429
3430                 if ( 0 != $newid ) { # Target exists; check for validity
3431                         if ( !$this->isValidMoveTarget( $nt ) ) {
3432                                 $errors[] = array( 'articleexists' );
3433                         }
3434                 } else {
3435                         $tp = $nt->getTitleProtection();
3436                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3437                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3438                                 $errors[] = array( 'cantmove-titleprotected' );
3439                         }
3440                 }
3441                 if ( empty( $errors ) ) {
3442                         return true;
3443                 }
3444                 return $errors;
3445         }
3446
3447         /**
3448          * Check if the requested move target is a valid file move target
3449          * @param Title $nt Target title
3450          * @return array List of errors
3451          */
3452         protected function validateFileMoveOperation( $nt ) {
3453                 global $wgUser;
3454
3455                 $errors = array();
3456
3457                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3458
3459                 $file = wfLocalFile( $this );
3460                 if ( $file->exists() ) {
3461                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3462                                 $errors[] = array( 'imageinvalidfilename' );
3463                         }
3464                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3465                                 $errors[] = array( 'imagetypemismatch' );
3466                         }
3467                 }
3468
3469                 if ( $nt->getNamespace() != NS_FILE ) {
3470                         $errors[] = array( 'imagenocrossnamespace' );
3471                         // From here we want to do checks on a file object, so if we can't
3472                         // create one, we must return.
3473                         return $errors;
3474                 }
3475
3476                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3477
3478                 $destFile = wfLocalFile( $nt );
3479                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3480                         $errors[] = array( 'file-exists-sharedrepo' );
3481                 }
3482
3483                 return $errors;
3484         }
3485
3486         /**
3487          * Move a title to a new location
3488          *
3489          * @param $nt Title the new title
3490          * @param $auth Bool indicates whether $wgUser's permissions
3491          *  should be checked
3492          * @param $reason String the reason for the move
3493          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3494          *  Ignored if the user doesn't have the suppressredirect right.
3495          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3496          */
3497         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3498                 global $wgUser;
3499                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3500                 if ( is_array( $err ) ) {
3501                         // Auto-block user's IP if the account was "hard" blocked
3502                         $wgUser->spreadAnyEditBlock();
3503                         return $err;
3504                 }
3505
3506                 // If it is a file, move it first.
3507                 // It is done before all other moving stuff is done because it's hard to revert.
3508                 $dbw = wfGetDB( DB_MASTER );
3509                 if ( $this->getNamespace() == NS_FILE ) {
3510                         $file = wfLocalFile( $this );
3511                         if ( $file->exists() ) {
3512                                 $status = $file->move( $nt );
3513                                 if ( !$status->isOk() ) {
3514                                         return $status->getErrorsArray();
3515                                 }
3516                         }
3517                         // Clear RepoGroup process cache
3518                         RepoGroup::singleton()->clearCache( $this );
3519                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3520                 }
3521
3522                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3523                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3524                 $protected = $this->isProtected();
3525
3526                 // Do the actual move
3527                 $this->moveToInternal( $nt, $reason, $createRedirect );
3528
3529                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3530                 // cl_timestamp, which may disturb time-based lists on some sites.
3531                 $prefixes = $dbw->select(
3532                         'categorylinks',
3533                         array( 'cl_sortkey_prefix', 'cl_to' ),
3534                         array( 'cl_from' => $pageid ),
3535                         __METHOD__
3536                 );
3537                 foreach ( $prefixes as $prefixRow ) {
3538                         $prefix = $prefixRow->cl_sortkey_prefix;
3539                         $catTo = $prefixRow->cl_to;
3540                         $dbw->update( 'categorylinks',
3541                                 array(
3542                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3543                                                 $nt->getCategorySortkey( $prefix ) ),
3544                                         'cl_timestamp=cl_timestamp' ),
3545                                 array(
3546                                         'cl_from' => $pageid,
3547                                         'cl_to' => $catTo ),
3548                                 __METHOD__
3549                         );
3550                 }
3551
3552                 $redirid = $this->getArticleID();
3553
3554                 if ( $protected ) {
3555                         # Protect the redirect title as the title used to be...
3556                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3557                                 array(
3558                                         'pr_page'    => $redirid,
3559                                         'pr_type'    => 'pr_type',
3560                                         'pr_level'   => 'pr_level',
3561                                         'pr_cascade' => 'pr_cascade',
3562                                         'pr_user'    => 'pr_user',
3563                                         'pr_expiry'  => 'pr_expiry'
3564                                 ),
3565                                 array( 'pr_page' => $pageid ),
3566                                 __METHOD__,
3567                                 array( 'IGNORE' )
3568                         );
3569                         # Update the protection log
3570                         $log = new LogPage( 'protect' );
3571                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3572                         if ( $reason ) {
3573                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3574                         }
3575                         // @todo FIXME: $params?
3576                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3577                 }
3578
3579                 # Update watchlists
3580                 $oldnamespace = $this->getNamespace() & ~1;
3581                 $newnamespace = $nt->getNamespace() & ~1;
3582                 $oldtitle = $this->getDBkey();
3583                 $newtitle = $nt->getDBkey();
3584
3585                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3586                         WatchedItem::duplicateEntries( $this, $nt );
3587                 }
3588
3589                 $dbw->commit( __METHOD__ );
3590
3591                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3592                 return true;
3593         }
3594
3595         /**
3596          * Move page to a title which is either a redirect to the
3597          * source page or nonexistent
3598          *
3599          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3600          * @param $reason String The reason for the move
3601          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3602          *   if the user doesn't have the suppressredirect right
3603          * @throws MWException
3604          */
3605         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3606                 global $wgUser, $wgContLang;
3607
3608                 if ( $nt->exists() ) {
3609                         $moveOverRedirect = true;
3610                         $logType = 'move_redir';
3611                 } else {
3612                         $moveOverRedirect = false;
3613                         $logType = 'move';
3614                 }
3615
3616                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3617
3618                 $logEntry = new ManualLogEntry( 'move', $logType );
3619                 $logEntry->setPerformer( $wgUser );
3620                 $logEntry->setTarget( $this );
3621                 $logEntry->setComment( $reason );
3622                 $logEntry->setParameters( array(
3623                         '4::target' => $nt->getPrefixedText(),
3624                         '5::noredir' => $redirectSuppressed ? '1': '0',
3625                 ) );
3626
3627                 $formatter = LogFormatter::newFromEntry( $logEntry );
3628                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3629                 $comment = $formatter->getPlainActionText();
3630                 if ( $reason ) {
3631                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3632                 }
3633                 # Truncate for whole multibyte characters.
3634                 $comment = $wgContLang->truncate( $comment, 255 );
3635
3636                 $oldid = $this->getArticleID();
3637
3638                 $dbw = wfGetDB( DB_MASTER );
3639
3640                 $newpage = WikiPage::factory( $nt );
3641
3642                 if ( $moveOverRedirect ) {
3643                         $newid = $nt->getArticleID();
3644
3645                         # Delete the old redirect. We don't save it to history since
3646                         # by definition if we've got here it's rather uninteresting.
3647                         # We have to remove it so that the next step doesn't trigger
3648                         # a conflict on the unique namespace+title index...
3649                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3650
3651                         $newpage->doDeleteUpdates( $newid );
3652                 }
3653
3654                 # Save a null revision in the page's history notifying of the move
3655                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3656                 if ( !is_object( $nullRevision ) ) {
3657                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3658                 }
3659                 $nullRevId = $nullRevision->insertOn( $dbw );
3660
3661                 # Change the name of the target page:
3662                 $dbw->update( 'page',
3663                         /* SET */ array(
3664                                 'page_namespace' => $nt->getNamespace(),
3665                                 'page_title'     => $nt->getDBkey(),
3666                         ),
3667                         /* WHERE */ array( 'page_id' => $oldid ),
3668                         __METHOD__
3669                 );
3670
3671                 $this->resetArticleID( 0 );
3672                 $nt->resetArticleID( $oldid );
3673
3674                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3675
3676                 wfRunHooks( 'NewRevisionFromEditComplete',
3677                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3678
3679                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3680
3681                 if ( !$moveOverRedirect ) {
3682                         WikiPage::onArticleCreate( $nt );
3683                 }
3684
3685                 # Recreate the redirect, this time in the other direction.
3686                 if ( $redirectSuppressed ) {
3687                         WikiPage::onArticleDelete( $this );
3688                 } else {
3689                         $mwRedir = MagicWord::get( 'redirect' );
3690                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3691                         $redirectArticle = WikiPage::factory( $this );
3692                         $newid = $redirectArticle->insertOn( $dbw );
3693                         if ( $newid ) { // sanity
3694                                 $redirectRevision = new Revision( array(
3695                                         'page'    => $newid,
3696                                         'comment' => $comment,
3697                                         'text'    => $redirectText ) );
3698                                 $redirectRevision->insertOn( $dbw );
3699                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3700
3701                                 wfRunHooks( 'NewRevisionFromEditComplete',
3702                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3703
3704                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3705                         }
3706                 }
3707
3708                 # Log the move
3709                 $logid = $logEntry->insert();
3710                 $logEntry->publish( $logid );
3711         }
3712
3713         /**
3714          * Move this page's subpages to be subpages of $nt
3715          *
3716          * @param $nt Title Move target
3717          * @param $auth bool Whether $wgUser's permissions should be checked
3718          * @param $reason string The reason for the move
3719          * @param $createRedirect bool Whether to create redirects from the old subpages to
3720          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3721          * @return mixed array with old page titles as keys, and strings (new page titles) or
3722          *     arrays (errors) as values, or an error array with numeric indices if no pages
3723          *     were moved
3724          */
3725         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3726                 global $wgMaximumMovedPages;
3727                 // Check permissions
3728                 if ( !$this->userCan( 'move-subpages' ) ) {
3729                         return array( 'cant-move-subpages' );
3730                 }
3731                 // Do the source and target namespaces support subpages?
3732                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3733                         return array( 'namespace-nosubpages',
3734                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3735                 }
3736                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3737                         return array( 'namespace-nosubpages',
3738                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3739                 }
3740
3741                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3742                 $retval = array();
3743                 $count = 0;
3744                 foreach ( $subpages as $oldSubpage ) {
3745                         $count++;
3746                         if ( $count > $wgMaximumMovedPages ) {
3747                                 $retval[$oldSubpage->getPrefixedTitle()] =
3748                                                 array( 'movepage-max-pages',
3749                                                         $wgMaximumMovedPages );
3750                                 break;
3751                         }
3752
3753                         // We don't know whether this function was called before
3754                         // or after moving the root page, so check both
3755                         // $this and $nt
3756                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3757                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3758                         {
3759                                 // When moving a page to a subpage of itself,
3760                                 // don't move it twice
3761                                 continue;
3762                         }
3763                         $newPageName = preg_replace(
3764                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3765                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3766                                         $oldSubpage->getDBkey() );
3767                         if ( $oldSubpage->isTalkPage() ) {
3768                                 $newNs = $nt->getTalkPage()->getNamespace();
3769                         } else {
3770                                 $newNs = $nt->getSubjectPage()->getNamespace();
3771                         }
3772                         # Bug 14385: we need makeTitleSafe because the new page names may
3773                         # be longer than 255 characters.
3774                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3775
3776                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3777                         if ( $success === true ) {
3778                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3779                         } else {
3780                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3781                         }
3782                 }
3783                 return $retval;
3784         }
3785
3786         /**
3787          * Checks if this page is just a one-rev redirect.
3788          * Adds lock, so don't use just for light purposes.
3789          *
3790          * @return Bool
3791          */
3792         public function isSingleRevRedirect() {
3793                 global $wgContentHandlerUseDB;
3794
3795                 $dbw = wfGetDB( DB_MASTER );
3796
3797                 # Is it a redirect?
3798                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3799                 if ( $wgContentHandlerUseDB ) $fields[] = 'page_content_model';
3800
3801                 $row = $dbw->selectRow( 'page',
3802                         $fields,
3803                         $this->pageCond(),
3804                         __METHOD__,
3805                         array( 'FOR UPDATE' )
3806                 );
3807                 # Cache some fields we may want
3808                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3809                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3810                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3811                 $this->mContentModel = $row && isset( $row->page_content_model ) ? intval( $row->page_content_model ) : false;
3812                 if ( !$this->mRedirect ) {
3813                         return false;
3814                 }
3815                 # Does the article have a history?
3816                 $row = $dbw->selectField( array( 'page', 'revision' ),
3817                         'rev_id',
3818                         array( 'page_namespace' => $this->getNamespace(),
3819                                 'page_title' => $this->getDBkey(),
3820                                 'page_id=rev_page',
3821                                 'page_latest != rev_id'
3822                         ),
3823                         __METHOD__,
3824                         array( 'FOR UPDATE' )
3825                 );
3826                 # Return true if there was no history
3827                 return ( $row === false );
3828         }
3829
3830         /**
3831          * Checks if $this can be moved to a given Title
3832          * - Selects for update, so don't call it unless you mean business
3833          *
3834          * @param $nt Title the new title to check
3835          * @return Bool
3836          */
3837         public function isValidMoveTarget( $nt ) {
3838                 # Is it an existing file?
3839                 if ( $nt->getNamespace() == NS_FILE ) {
3840                         $file = wfLocalFile( $nt );
3841                         if ( $file->exists() ) {
3842                                 wfDebug( __METHOD__ . ": file exists\n" );
3843                                 return false;
3844                         }
3845                 }
3846                 # Is it a redirect with no history?
3847                 if ( !$nt->isSingleRevRedirect() ) {
3848                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3849                         return false;
3850                 }
3851                 # Get the article text
3852                 $rev = Revision::newFromTitle( $nt );
3853                 if( !is_object( $rev ) ){
3854                         return false;
3855                 }
3856                 $content = $rev->getContent();
3857                 # Does the redirect point to the source?
3858                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3859                 $redirTitle = $content->getRedirectTarget();
3860
3861                 if ( $redirTitle ) {
3862                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3863                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
3864                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3865                                 return false;
3866                         } else {
3867                                 return true;
3868                         }
3869                 } else {
3870                         # Fail safe (not a redirect after all. strange.)
3871                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() . " is a redirect, but it doesn't contain a valid redirect.\n" );
3872                         return false;
3873                 }
3874         }
3875
3876         /**
3877          * Get categories to which this Title belongs and return an array of
3878          * categories' names.
3879          *
3880          * @return Array of parents in the form:
3881          *        $parent => $currentarticle
3882          */
3883         public function getParentCategories() {
3884                 global $wgContLang;
3885
3886                 $data = array();
3887
3888                 $titleKey = $this->getArticleID();
3889
3890                 if ( $titleKey === 0 ) {
3891                         return $data;
3892                 }
3893
3894                 $dbr = wfGetDB( DB_SLAVE );
3895
3896                 $res = $dbr->select( 'categorylinks', '*',
3897                         array(
3898                                 'cl_from' => $titleKey,
3899                         ),
3900                         __METHOD__,
3901                         array()
3902                 );
3903
3904                 if ( $dbr->numRows( $res ) > 0 ) {
3905                         foreach ( $res as $row ) {
3906                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3907                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3908                         }
3909                 }
3910                 return $data;
3911         }
3912
3913         /**
3914          * Get a tree of parent categories
3915          *
3916          * @param $children Array with the children in the keys, to check for circular refs
3917          * @return Array Tree of parent categories
3918          */
3919         public function getParentCategoryTree( $children = array() ) {
3920                 $stack = array();
3921                 $parents = $this->getParentCategories();
3922
3923                 if ( $parents ) {
3924                         foreach ( $parents as $parent => $current ) {
3925                                 if ( array_key_exists( $parent, $children ) ) {
3926                                         # Circular reference
3927                                         $stack[$parent] = array();
3928                                 } else {
3929                                         $nt = Title::newFromText( $parent );
3930                                         if ( $nt ) {
3931                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3932                                         }
3933                                 }
3934                         }
3935                 }
3936
3937                 return $stack;
3938         }
3939
3940         /**
3941          * Get an associative array for selecting this title from
3942          * the "page" table
3943          *
3944          * @return Array suitable for the $where parameter of DB::select()
3945          */
3946         public function pageCond() {
3947                 if ( $this->mArticleID > 0 ) {
3948                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3949                         return array( 'page_id' => $this->mArticleID );
3950                 } else {
3951                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3952                 }
3953         }
3954
3955         /**
3956          * Get the revision ID of the previous revision
3957          *
3958          * @param $revId Int Revision ID. Get the revision that was before this one.
3959          * @param $flags Int Title::GAID_FOR_UPDATE
3960          * @return Int|Bool Old revision ID, or FALSE if none exists
3961          */
3962         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3963                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3964                 $revId = $db->selectField( 'revision', 'rev_id',
3965                         array(
3966                                 'rev_page' => $this->getArticleID( $flags ),
3967                                 'rev_id < ' . intval( $revId )
3968                         ),
3969                         __METHOD__,
3970                         array( 'ORDER BY' => 'rev_id DESC' )
3971                 );
3972
3973                 if ( $revId === false ) {
3974                         return false;
3975                 } else {
3976                         return intval( $revId );
3977                 }
3978         }
3979
3980         /**
3981          * Get the revision ID of the next revision
3982          *
3983          * @param $revId Int Revision ID. Get the revision that was after this one.
3984          * @param $flags Int Title::GAID_FOR_UPDATE
3985          * @return Int|Bool Next revision ID, or FALSE if none exists
3986          */
3987         public function getNextRevisionID( $revId, $flags = 0 ) {
3988                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3989                 $revId = $db->selectField( 'revision', 'rev_id',
3990                         array(
3991                                 'rev_page' => $this->getArticleID( $flags ),
3992                                 'rev_id > ' . intval( $revId )
3993                         ),
3994                         __METHOD__,
3995                         array( 'ORDER BY' => 'rev_id' )
3996                 );
3997
3998                 if ( $revId === false ) {
3999                         return false;
4000                 } else {
4001                         return intval( $revId );
4002                 }
4003         }
4004
4005         /**
4006          * Get the first revision of the page
4007          *
4008          * @param $flags Int Title::GAID_FOR_UPDATE
4009          * @return Revision|Null if page doesn't exist
4010          */
4011         public function getFirstRevision( $flags = 0 ) {
4012                 $pageId = $this->getArticleID( $flags );
4013                 if ( $pageId ) {
4014                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4015                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4016                                 array( 'rev_page' => $pageId ),
4017                                 __METHOD__,
4018                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4019                         );
4020                         if ( $row ) {
4021                                 return new Revision( $row );
4022                         }
4023                 }
4024                 return null;
4025         }
4026
4027         /**
4028          * Get the oldest revision timestamp of this page
4029          *
4030          * @param $flags Int Title::GAID_FOR_UPDATE
4031          * @return String: MW timestamp
4032          */
4033         public function getEarliestRevTime( $flags = 0 ) {
4034                 $rev = $this->getFirstRevision( $flags );
4035                 return $rev ? $rev->getTimestamp() : null;
4036         }
4037
4038         /**
4039          * Check if this is a new page
4040          *
4041          * @return bool
4042          */
4043         public function isNewPage() {
4044                 $dbr = wfGetDB( DB_SLAVE );
4045                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4046         }
4047
4048         /**
4049          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4050          *
4051          * @return bool
4052          */
4053         public function isBigDeletion() {
4054                 global $wgDeleteRevisionsLimit;
4055
4056                 if ( !$wgDeleteRevisionsLimit ) {
4057                         return false;
4058                 }
4059
4060                 $revCount = $this->estimateRevisionCount();
4061                 return $revCount > $wgDeleteRevisionsLimit;
4062         }
4063
4064         /**
4065          * Get the  approximate revision count of this page.
4066          *
4067          * @return int
4068          */
4069         public function estimateRevisionCount() {
4070                 if ( !$this->exists() ) {
4071                         return 0;
4072                 }
4073
4074                 if ( $this->mEstimateRevisions === null ) {
4075                         $dbr = wfGetDB( DB_SLAVE );
4076                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4077                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4078                 }
4079
4080                 return $this->mEstimateRevisions;
4081         }
4082
4083         /**
4084          * Get the number of revisions between the given revision.
4085          * Used for diffs and other things that really need it.
4086          *
4087          * @param $old int|Revision Old revision or rev ID (first before range)
4088          * @param $new int|Revision New revision or rev ID (first after range)
4089          * @return Int Number of revisions between these revisions.
4090          */
4091         public function countRevisionsBetween( $old, $new ) {
4092                 if ( !( $old instanceof Revision ) ) {
4093                         $old = Revision::newFromTitle( $this, (int)$old );
4094                 }
4095                 if ( !( $new instanceof Revision ) ) {
4096                         $new = Revision::newFromTitle( $this, (int)$new );
4097                 }
4098                 if ( !$old || !$new ) {
4099                         return 0; // nothing to compare
4100                 }
4101                 $dbr = wfGetDB( DB_SLAVE );
4102                 return (int)$dbr->selectField( 'revision', 'count(*)',
4103                         array(
4104                                 'rev_page' => $this->getArticleID(),
4105                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4106                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4107                         ),
4108                         __METHOD__
4109                 );
4110         }
4111
4112         /**
4113          * Get the number of authors between the given revision IDs.
4114          * Used for diffs and other things that really need it.
4115          *
4116          * @param $old int|Revision Old revision or rev ID (first before range)
4117          * @param $new int|Revision New revision or rev ID (first after range)
4118          * @param $limit Int Maximum number of authors
4119          * @return Int Number of revision authors between these revisions.
4120          */
4121         public function countAuthorsBetween( $old, $new, $limit ) {
4122                 if ( !( $old instanceof Revision ) ) {
4123                         $old = Revision::newFromTitle( $this, (int)$old );
4124                 }
4125                 if ( !( $new instanceof Revision ) ) {
4126                         $new = Revision::newFromTitle( $this, (int)$new );
4127                 }
4128                 if ( !$old || !$new ) {
4129                         return 0; // nothing to compare
4130                 }
4131                 $dbr = wfGetDB( DB_SLAVE );
4132                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4133                         array(
4134                                 'rev_page' => $this->getArticleID(),
4135                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4136                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4137                         ), __METHOD__,
4138                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4139                 );
4140                 return (int)$dbr->numRows( $res );
4141         }
4142
4143         /**
4144          * Compare with another title.
4145          *
4146          * @param $title Title
4147          * @return Bool
4148          */
4149         public function equals( Title $title ) {
4150                 // Note: === is necessary for proper matching of number-like titles.
4151                 return $this->getInterwiki() === $title->getInterwiki()
4152                         && $this->getNamespace() == $title->getNamespace()
4153                         && $this->getDBkey() === $title->getDBkey();
4154         }
4155
4156         /**
4157          * Check if this title is a subpage of another title
4158          *
4159          * @param $title Title
4160          * @return Bool
4161          */
4162         public function isSubpageOf( Title $title ) {
4163                 return $this->getInterwiki() === $title->getInterwiki()
4164                         && $this->getNamespace() == $title->getNamespace()
4165                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4166         }
4167
4168         /**
4169          * Check if page exists.  For historical reasons, this function simply
4170          * checks for the existence of the title in the page table, and will
4171          * thus return false for interwiki links, special pages and the like.
4172          * If you want to know if a title can be meaningfully viewed, you should
4173          * probably call the isKnown() method instead.
4174          *
4175          * @return Bool
4176          */
4177         public function exists() {
4178                 return $this->getArticleID() != 0;
4179         }
4180
4181         /**
4182          * Should links to this title be shown as potentially viewable (i.e. as
4183          * "bluelinks"), even if there's no record by this title in the page
4184          * table?
4185          *
4186          * This function is semi-deprecated for public use, as well as somewhat
4187          * misleadingly named.  You probably just want to call isKnown(), which
4188          * calls this function internally.
4189          *
4190          * (ISSUE: Most of these checks are cheap, but the file existence check
4191          * can potentially be quite expensive.  Including it here fixes a lot of
4192          * existing code, but we might want to add an optional parameter to skip
4193          * it and any other expensive checks.)
4194          *
4195          * @return Bool
4196          */
4197         public function isAlwaysKnown() {
4198                 $isKnown = null;
4199
4200                 /**
4201                  * Allows overriding default behaviour for determining if a page exists.
4202                  * If $isKnown is kept as null, regular checks happen. If it's
4203                  * a boolean, this value is returned by the isKnown method.
4204                  *
4205                  * @since 1.20
4206                  *
4207                  * @param Title $title
4208                  * @param boolean|null $isKnown
4209                  */
4210                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4211
4212                 if ( !is_null( $isKnown ) ) {
4213                         return $isKnown;
4214                 }
4215
4216                 if ( $this->mInterwiki != '' ) {
4217                         return true;  // any interwiki link might be viewable, for all we know
4218                 }
4219
4220                 switch( $this->mNamespace ) {
4221                         case NS_MEDIA:
4222                         case NS_FILE:
4223                                 // file exists, possibly in a foreign repo
4224                                 return (bool)wfFindFile( $this );
4225                         case NS_SPECIAL:
4226                                 // valid special page
4227                                 return SpecialPageFactory::exists( $this->getDBkey() );
4228                         case NS_MAIN:
4229                                 // selflink, possibly with fragment
4230                                 return $this->mDbkeyform == '';
4231                         case NS_MEDIAWIKI:
4232                                 // known system message
4233                                 return $this->hasSourceText() !== false;
4234                         default:
4235                                 return false;
4236                 }
4237         }
4238
4239         /**
4240          * Does this title refer to a page that can (or might) be meaningfully
4241          * viewed?  In particular, this function may be used to determine if
4242          * links to the title should be rendered as "bluelinks" (as opposed to
4243          * "redlinks" to non-existent pages).
4244          * Adding something else to this function will cause inconsistency
4245          * since LinkHolderArray calls isAlwaysKnown() and does its own
4246          * page existence check.
4247          *
4248          * @return Bool
4249          */
4250         public function isKnown() {
4251                 return $this->isAlwaysKnown() || $this->exists();
4252         }
4253
4254         /**
4255          * Does this page have source text?
4256          *
4257          * @return Boolean
4258          */
4259         public function hasSourceText() {
4260                 if ( $this->exists() ) {
4261                         return true;
4262                 }
4263
4264                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4265                         // If the page doesn't exist but is a known system message, default
4266                         // message content will be displayed, same for language subpages-
4267                         // Use always content language to avoid loading hundreds of languages
4268                         // to get the link color.
4269                         global $wgContLang;
4270                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4271                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4272                         return $message->exists();
4273                 }
4274
4275                 return false;
4276         }
4277
4278         /**
4279          * Get the default message text or false if the message doesn't exist
4280          *
4281          * @return String or false
4282          */
4283         public function getDefaultMessageText() {
4284                 global $wgContLang;
4285
4286                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4287                         return false;
4288                 }
4289
4290                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4291                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4292
4293                 if ( $message->exists() ) {
4294                         return $message->plain();
4295                 } else {
4296                         return false;
4297                 }
4298         }
4299
4300         /**
4301          * Updates page_touched for this page; called from LinksUpdate.php
4302          *
4303          * @return Bool true if the update succeded
4304          */
4305         public function invalidateCache() {
4306                 if ( wfReadOnly() ) {
4307                         return false;
4308                 }
4309                 $dbw = wfGetDB( DB_MASTER );
4310                 $success = $dbw->update(
4311                         'page',
4312                         array( 'page_touched' => $dbw->timestamp() ),
4313                         $this->pageCond(),
4314                         __METHOD__
4315                 );
4316                 HTMLFileCache::clearFileCache( $this );
4317                 return $success;
4318         }
4319
4320         /**
4321          * Update page_touched timestamps and send squid purge messages for
4322          * pages linking to this title. May be sent to the job queue depending
4323          * on the number of links. Typically called on create and delete.
4324          */
4325         public function touchLinks() {
4326                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4327                 $u->doUpdate();
4328
4329                 if ( $this->getNamespace() == NS_CATEGORY ) {
4330                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4331                         $u->doUpdate();
4332                 }
4333         }
4334
4335         /**
4336          * Get the last touched timestamp
4337          *
4338          * @param $db DatabaseBase: optional db
4339          * @return String last-touched timestamp
4340          */
4341         public function getTouched( $db = null ) {
4342                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4343                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4344                 return $touched;
4345         }
4346
4347         /**
4348          * Get the timestamp when this page was updated since the user last saw it.
4349          *
4350          * @param $user User
4351          * @return String|Null
4352          */
4353         public function getNotificationTimestamp( $user = null ) {
4354                 global $wgUser, $wgShowUpdatedMarker;
4355                 // Assume current user if none given
4356                 if ( !$user ) {
4357                         $user = $wgUser;
4358                 }
4359                 // Check cache first
4360                 $uid = $user->getId();
4361                 // avoid isset here, as it'll return false for null entries
4362                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4363                         return $this->mNotificationTimestamp[$uid];
4364                 }
4365                 if ( !$uid || !$wgShowUpdatedMarker ) {
4366                         return $this->mNotificationTimestamp[$uid] = false;
4367                 }
4368                 // Don't cache too much!
4369                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4370                         $this->mNotificationTimestamp = array();
4371                 }
4372                 $dbr = wfGetDB( DB_SLAVE );
4373                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4374                         'wl_notificationtimestamp',
4375                         array(
4376                                 'wl_user' => $user->getId(),
4377                                 'wl_namespace' => $this->getNamespace(),
4378                                 'wl_title' => $this->getDBkey(),
4379                         ),
4380                         __METHOD__
4381                 );
4382                 return $this->mNotificationTimestamp[$uid];
4383         }
4384
4385         /**
4386          * Generate strings used for xml 'id' names in monobook tabs
4387          *
4388          * @param $prepend string defaults to 'nstab-'
4389          * @return String XML 'id' name
4390          */
4391         public function getNamespaceKey( $prepend = 'nstab-' ) {
4392                 global $wgContLang;
4393                 // Gets the subject namespace if this title
4394                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4395                 // Checks if cononical namespace name exists for namespace
4396                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4397                         // Uses canonical namespace name
4398                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4399                 } else {
4400                         // Uses text of namespace
4401                         $namespaceKey = $this->getSubjectNsText();
4402                 }
4403                 // Makes namespace key lowercase
4404                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4405                 // Uses main
4406                 if ( $namespaceKey == '' ) {
4407                         $namespaceKey = 'main';
4408                 }
4409                 // Changes file to image for backwards compatibility
4410                 if ( $namespaceKey == 'file' ) {
4411                         $namespaceKey = 'image';
4412                 }
4413                 return $prepend . $namespaceKey;
4414         }
4415
4416         /**
4417          * Get all extant redirects to this Title
4418          *
4419          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4420          * @return Array of Title redirects to this title
4421          */
4422         public function getRedirectsHere( $ns = null ) {
4423                 $redirs = array();
4424
4425                 $dbr = wfGetDB( DB_SLAVE );
4426                 $where = array(
4427                         'rd_namespace' => $this->getNamespace(),
4428                         'rd_title' => $this->getDBkey(),
4429                         'rd_from = page_id'
4430                 );
4431                 if ( !is_null( $ns ) ) {
4432                         $where['page_namespace'] = $ns;
4433                 }
4434
4435                 $res = $dbr->select(
4436                         array( 'redirect', 'page' ),
4437                         array( 'page_namespace', 'page_title' ),
4438                         $where,
4439                         __METHOD__
4440                 );
4441
4442                 foreach ( $res as $row ) {
4443                         $redirs[] = self::newFromRow( $row );
4444                 }
4445                 return $redirs;
4446         }
4447
4448         /**
4449          * Check if this Title is a valid redirect target
4450          *
4451          * @return Bool
4452          */
4453         public function isValidRedirectTarget() {
4454                 global $wgInvalidRedirectTargets;
4455
4456                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4457                 if ( $this->isSpecial( 'Userlogout' ) ) {
4458                         return false;
4459                 }
4460
4461                 foreach ( $wgInvalidRedirectTargets as $target ) {
4462                         if ( $this->isSpecial( $target ) ) {
4463                                 return false;
4464                         }
4465                 }
4466
4467                 return true;
4468         }
4469
4470         /**
4471          * Get a backlink cache object
4472          *
4473          * @return BacklinkCache
4474          */
4475         function getBacklinkCache() {
4476                 if ( is_null( $this->mBacklinkCache ) ) {
4477                         $this->mBacklinkCache = new BacklinkCache( $this );
4478                 }
4479                 return $this->mBacklinkCache;
4480         }
4481
4482         /**
4483          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4484          *
4485          * @return Boolean
4486          */
4487         public function canUseNoindex() {
4488                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4489
4490                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4491                         ? $wgContentNamespaces
4492                         : $wgExemptFromUserRobotsControl;
4493
4494                 return !in_array( $this->mNamespace, $bannedNamespaces );
4495
4496         }
4497
4498         /**
4499          * Returns the raw sort key to be used for categories, with the specified
4500          * prefix.  This will be fed to Collation::getSortKey() to get a
4501          * binary sortkey that can be used for actual sorting.
4502          *
4503          * @param $prefix string The prefix to be used, specified using
4504          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4505          *   prefix.
4506          * @return string
4507          */
4508         public function getCategorySortkey( $prefix = '' ) {
4509                 $unprefixed = $this->getText();
4510
4511                 // Anything that uses this hook should only depend
4512                 // on the Title object passed in, and should probably
4513                 // tell the users to run updateCollations.php --force
4514                 // in order to re-sort existing category relations.
4515                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4516                 if ( $prefix !== '' ) {
4517                         # Separate with a line feed, so the unprefixed part is only used as
4518                         # a tiebreaker when two pages have the exact same prefix.
4519                         # In UCA, tab is the only character that can sort above LF
4520                         # so we strip both of them from the original prefix.
4521                         $prefix = strtr( $prefix, "\n\t", '  ' );
4522                         return "$prefix\n$unprefixed";
4523                 }
4524                 return $unprefixed;
4525         }
4526
4527         /**
4528          * Get the language in which the content of this page is written.
4529          * Defaults to $wgContLang, but in certain cases it can be e.g.
4530          * $wgLang (such as special pages, which are in the user language).
4531          *
4532          * @since 1.18
4533          * @return Language
4534          */
4535         public function getPageLanguage() {
4536                 global $wgLang;
4537                 if ( $this->isSpecialPage() ) {
4538                         // special pages are in the user language
4539                         return $wgLang;
4540                 } elseif ( $this->isCssOrJsPage() || $this->isCssJsSubpage() ) {
4541                         // css/js should always be LTR and is, in fact, English
4542                         return wfGetLangObj( 'en' );
4543                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4544                         // Parse mediawiki messages with correct target language
4545                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4546                         return wfGetLangObj( $lang );
4547                 }
4548                 global $wgContLang;
4549                 // If nothing special, it should be in the wiki content language
4550                 $pageLang = $wgContLang;
4551                 // Hook at the end because we don't want to override the above stuff
4552                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4553                 return wfGetLangObj( $pageLang );
4554         }
4555 }