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          * Create a new Title from an article ID
 206          *
 207          * @param $id Int the page_id corresponding to the Title to create
 208          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 209          * @return Title the new object, or NULL on an error
 210          */
 211         public static function newFromID( $id, $flags = 0 ) {
 212                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 213                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 214                 if ( $row !== false ) {
 215                         $title = Title::newFromRow( $row );
 216                 } else {
 217                         $title = null;
 218                 }
 219                 return $title;
 220         }
 221
 222         /**
 223          * Make an array of titles from an array of IDs
 224          *
 225          * @param $ids Array of Int Array of IDs
 226          * @return Array of Titles
 227          */
 228         public static function newFromIDs( $ids ) {
 229                 if ( !count( $ids ) ) {
 230                         return array();
 231                 }
 232                 $dbr = wfGetDB( DB_SLAVE );
 233
 234                 $res = $dbr->select(
 235                         'page',
 236                         array(
 237                                 'page_namespace', 'page_title', 'page_id',
 238                                 'page_len', 'page_is_redirect', 'page_latest',
 239                         ),
 240                         array( 'page_id' => $ids ),
 241                         __METHOD__
 242                 );
 243
 244                 $titles = array();
 245                 foreach ( $res as $row ) {
 246                         $titles[] = Title::newFromRow( $row );
 247                 }
 248                 return $titles;
 249         }
 250
 251         /**
 252          * Make a Title object from a DB row
 253          *
 254          * @param $row Object database row (needs at least page_title,page_namespace)
 255          * @return Title corresponding Title
 256          */
 257         public static function newFromRow( $row ) {
 258                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 259                 $t->loadFromRow( $row );
 260                 return $t;
 261         }
 262
 263         /**
 264          * Load Title object fields from a DB row.
 265          * If false is given, the title will be treated as non-existing.
 266          *
 267          * @param $row Object|bool database row
 268          */
 269         public function loadFromRow( $row ) {
 270                 if ( $row ) { // page found
 271                         if ( isset( $row->page_id ) )
 272                                 $this->mArticleID = (int)$row->page_id;
 273                         if ( isset( $row->page_len ) )
 274                                 $this->mLength = (int)$row->page_len;
 275                         if ( isset( $row->page_is_redirect ) )
 276                                 $this->mRedirect = (bool)$row->page_is_redirect;
 277                         if ( isset( $row->page_latest ) )
 278                                 $this->mLatestID = (int)$row->page_latest; # FIXME: whene3ver page_latest is updated, also update page_content_model
 279                         if ( isset( $row->page_content_model ) )
 280                                 $this->mContentModel = $row->page_content_model;
 281                         else
 282                                 $this->mContentModel = null; # initialized lazily in getContentModel()
 283                 } else { // page not found
 284                         $this->mArticleID = 0;
 285                         $this->mLength = 0;
 286                         $this->mRedirect = false;
 287                         $this->mLatestID = 0;
 288                         $this->mContentModel = null; # initialized lazily in getContentModel()
 289                 }
 290         }
 291
 292         /**
 293          * Create a new Title from a namespace index and a DB key.
 294          * It's assumed that $ns and $title are *valid*, for instance when
 295          * they came directly from the database or a special page name.
 296          * For convenience, spaces are converted to underscores so that
 297          * eg user_text fields can be used directly.
 298          *
 299          * @param $ns Int the namespace of the article
 300          * @param $title String the unprefixed database key form
 301          * @param $fragment String the link fragment (after the "#")
 302          * @param $interwiki String the interwiki prefix
 303          * @return Title the new object
 304          */
 305         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 306                 $t = new Title();
 307                 $t->mInterwiki = $interwiki;
 308                 $t->mFragment = $fragment;
 309                 $t->mNamespace = $ns = intval( $ns );
 310                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 311                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 312                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 313                 $t->mTextform = str_replace( '_', ' ', $title );
 314                 $t->mContentModel = null; # initialized lazily in getContentModel()
 315                 return $t;
 316         }
 317
 318         /**
 319          * Create a new Title from a namespace index and a DB key.
 320          * The parameters will be checked for validity, which is a bit slower
 321          * than makeTitle() but safer for user-provided data.
 322          *
 323          * @param $ns Int the namespace of the article
 324          * @param $title String database key form
 325          * @param $fragment String the link fragment (after the "#")
 326          * @param $interwiki String interwiki prefix
 327          * @return Title the new object, or NULL on an error
 328          */
 329         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 330                 if ( !MWNamespace::exists( $ns ) ) {
 331                         return null;
 332                 }
 333
 334                 $t = new Title();
 335                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 336                 if ( $t->secureAndSplit() ) {
 337                         return $t;
 338                 } else {
 339                         return null;
 340                 }
 341         }
 342
 343         /**
 344          * Create a new Title for the Main Page
 345          *
 346          * @return Title the new object
 347          */
 348         public static function newMainPage() {
 349                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 350                 // Don't give fatal errors if the message is broken
 351                 if ( !$title ) {
 352                         $title = Title::newFromText( 'Main Page' );
 353                 }
 354                 return $title;
 355         }
 356
 357         /**
 358          * Extract a redirect destination from a string and return the
 359          * Title, or null if the text doesn't contain a valid redirect
 360          * This will only return the very next target, useful for
 361          * the redirect table and other checks that don't need full recursion
 362          *
 363          * @param $text String: Text with possible redirect
 364          * @return Title: The corresponding Title
 365          */
 366         public static function newFromRedirect( $text ) {
 367                 return self::newFromRedirectInternal( $text );
 368         }
 369
 370         /**
 371          * Extract a redirect destination from a string and return the
 372          * Title, or null if the text doesn't contain a valid redirect
 373          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 374          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 375          *
 376          * @param $text String Text with possible redirect
 377          * @return Title
 378          */
 379         public static function newFromRedirectRecurse( $text ) {
 380                 $titles = self::newFromRedirectArray( $text );
 381                 return $titles ? array_pop( $titles ) : null;
 382         }
 383
 384         /**
 385          * Extract a redirect destination from a string and return an
 386          * array of Titles, or null if the text doesn't contain a valid redirect
 387          * The last element in the array is the final destination after all redirects
 388          * have been resolved (up to $wgMaxRedirects times)
 389          *
 390          * @param $text String Text with possible redirect
 391          * @return Array of Titles, with the destination last
 392          */
 393         public static function newFromRedirectArray( $text ) {
 394                 global $wgMaxRedirects;
 395                 $title = self::newFromRedirectInternal( $text );
 396                 if ( is_null( $title ) ) {
 397                         return null;
 398                 }
 399                 // recursive check to follow double redirects
 400                 $recurse = $wgMaxRedirects;
 401                 $titles = array( $title );
 402                 while ( --$recurse > 0 ) {
 403                         if ( $title->isRedirect() ) {
 404                                 $page = WikiPage::factory( $title );
 405                                 $newtitle = $page->getRedirectTarget();
 406                         } else {
 407                                 break;
 408                         }
 409                         // Redirects to some special pages are not permitted
 410                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 411                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 412                                 $title = $newtitle;
 413                                 $titles[] = $newtitle;
 414                         } else {
 415                                 break;
 416                         }
 417                 }
 418                 return $titles;
 419         }
 420
 421         /**
 422          * Really extract the redirect destination
 423          * Do not call this function directly, use one of the newFromRedirect* functions above
 424          *
 425          * @param $text String Text with possible redirect
 426          * @return Title
 427          */
 428         protected static function newFromRedirectInternal( $text ) {
 429                 global $wgMaxRedirects;
 430                 if ( $wgMaxRedirects < 1 ) {
 431                         //redirects are disabled, so quit early
 432                         return null;
 433                 }
 434                 $redir = MagicWord::get( 'redirect' );
 435                 $text = trim( $text );
 436                 if ( $redir->matchStartAndRemove( $text ) ) {
 437                         // Extract the first link and see if it's usable
 438                         // Ensure that it really does come directly after #REDIRECT
 439                         // Some older redirects included a colon, so don't freak about that!
 440                         $m = array();
 441                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 442                                 // Strip preceding colon used to "escape" categories, etc.
 443                                 // and URL-decode links
 444                                 if ( strpos( $m[1], '%' ) !== false ) {
 445                                         // Match behavior of inline link parsing here;
 446                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 447                                 }
 448                                 $title = Title::newFromText( $m[1] );
 449                                 // If the title is a redirect to bad special pages or is invalid, return null
 450                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 451                                         return null;
 452                                 }
 453                                 return $title;
 454                         }
 455                 }
 456                 return null;
 457         }
 458
 459         /**
 460          * Get the prefixed DB key associated with an ID
 461          *
 462          * @param $id Int the page_id of the article
 463          * @return Title an object representing the article, or NULL if no such article was found
 464          */
 465         public static function nameOf( $id ) {
 466                 $dbr = wfGetDB( DB_SLAVE );
 467
 468                 $s = $dbr->selectRow(
 469                         'page',
 470                         array( 'page_namespace', 'page_title' ),
 471                         array( 'page_id' => $id ),
 472                         __METHOD__
 473                 );
 474                 if ( $s === false ) {
 475                         return null;
 476                 }
 477
 478                 $n = self::makeName( $s->page_namespace, $s->page_title );
 479                 return $n;
 480         }
 481
 482         /**
 483          * Get a regex character class describing the legal characters in a link
 484          *
 485          * @return String the list of characters, not delimited
 486          */
 487         public static function legalChars() {
 488                 global $wgLegalTitleChars;
 489                 return $wgLegalTitleChars;
 490         }
 491
 492         /**
 493          * Returns a simple regex that will match on characters and sequences invalid in titles.
 494          * Note that this doesn't pick up many things that could be wrong with titles, but that
 495          * replacing this regex with something valid will make many titles valid.
 496          *
 497          * @return String regex string
 498          */
 499         static function getTitleInvalidRegex() {
 500                 static $rxTc = false;
 501                 if ( !$rxTc ) {
 502                         # Matching titles will be held as illegal.
 503                         $rxTc = '/' .
 504                                 # Any character not allowed is forbidden...
 505                                 '[^' . self::legalChars() . ']' .
 506                                 # URL percent encoding sequences interfere with the ability
 507                                 # to round-trip titles -- you can't link to them consistently.
 508                                 '|%[0-9A-Fa-f]{2}' .
 509                                 # XML/HTML character references produce similar issues.
 510                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 511                                 '|&#[0-9]+;' .
 512                                 '|&#x[0-9A-Fa-f]+;' .
 513                                 '/S';
 514                 }
 515
 516                 return $rxTc;
 517         }
 518
 519         /**
 520          * Get a string representation of a title suitable for
 521          * including in a search index
 522          *
 523          * @param $ns Int a namespace index
 524          * @param $title String text-form main part
 525          * @return String a stripped-down title string ready for the search index
 526          */
 527         public static function indexTitle( $ns, $title ) {
 528                 global $wgContLang;
 529
 530                 $lc = SearchEngine::legalSearchChars() . '&#;';
 531                 $t = $wgContLang->normalizeForSearch( $title );
 532                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 533                 $t = $wgContLang->lc( $t );
 534
 535                 # Handle 's, s'
 536                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 537                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 538
 539                 $t = preg_replace( "/\\s+/", ' ', $t );
 540
 541                 if ( $ns == NS_FILE ) {
 542                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 543                 }
 544                 return trim( $t );
 545         }
 546
 547         /**
 548          * Make a prefixed DB key from a DB key and a namespace index
 549          *
 550          * @param $ns Int numerical representation of the namespace
 551          * @param $title String the DB key form the title
 552          * @param $fragment String The link fragment (after the "#")
 553          * @param $interwiki String The interwiki prefix
 554          * @return String the prefixed form of the title
 555          */
 556         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 557                 global $wgContLang;
 558
 559                 $namespace = $wgContLang->getNsText( $ns );
 560                 $name = $namespace == '' ? $title : "$namespace:$title";
 561                 if ( strval( $interwiki ) != '' ) {
 562                         $name = "$interwiki:$name";
 563                 }
 564                 if ( strval( $fragment ) != '' ) {
 565                         $name .= '#' . $fragment;
 566                 }
 567                 return $name;
 568         }
 569
 570         /**
 571          * Escape a text fragment, say from a link, for a URL
 572          *
 573          * @param $fragment string containing a URL or link fragment (after the "#")
 574          * @return String: escaped string
 575          */
 576         static function escapeFragmentForURL( $fragment ) {
 577                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 578                 # fragments appear not to work in IE (at least up to 7) or in at least
 579                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 580                 # to care if they aren't encoded.
 581                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 582         }
 583
 584         /**
 585          * Callback for usort() to do title sorts by (namespace, title)
 586          *
 587          * @param $a Title
 588          * @param $b Title
 589          *
 590          * @return Integer: result of string comparison, or namespace comparison
 591          */
 592         public static function compare( $a, $b ) {
 593                 if ( $a->getNamespace() == $b->getNamespace() ) {
 594                         return strcmp( $a->getText(), $b->getText() );
 595                 } else {
 596                         return $a->getNamespace() - $b->getNamespace();
 597                 }
 598         }
 599
 600         /**
 601          * Determine whether the object refers to a page within
 602          * this project.
 603          *
 604          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 605          */
 606         public function isLocal() {
 607                 if ( $this->mInterwiki != '' ) {
 608                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 609                 } else {
 610                         return true;
 611                 }
 612         }
 613
 614         /**
 615          * Is this Title interwiki?
 616          *
 617          * @return Bool
 618          */
 619         public function isExternal() {
 620                 return ( $this->mInterwiki != '' );
 621         }
 622
 623         /**
 624          * Get the interwiki prefix (or null string)
 625          *
 626          * @return String Interwiki prefix
 627          */
 628         public function getInterwiki() {
 629                 return $this->mInterwiki;
 630         }
 631
 632         /**
 633          * Determine whether the object refers to a page within
 634          * this project and is transcludable.
 635          *
 636          * @return Bool TRUE if this is transcludable
 637          */
 638         public function isTrans() {
 639                 if ( $this->mInterwiki == '' ) {
 640                         return false;
 641                 }
 642
 643                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 644         }
 645
 646         /**
 647          * Returns the DB name of the distant wiki which owns the object.
 648          *
 649          * @return String the DB name
 650          */
 651         public function getTransWikiID() {
 652                 if ( $this->mInterwiki == '' ) {
 653                         return false;
 654                 }
 655
 656                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 657         }
 658
 659         /**
 660          * Get the text form (spaces not underscores) of the main part
 661          *
 662          * @return String Main part of the title
 663          */
 664         public function getText() {
 665                 return $this->mTextform;
 666         }
 667
 668         /**
 669          * Get the URL-encoded form of the main part
 670          *
 671          * @return String Main part of the title, URL-encoded
 672          */
 673         public function getPartialURL() {
 674                 return $this->mUrlform;
 675         }
 676
 677         /**
 678          * Get the main part with underscores
 679          *
 680          * @return String: Main part of the title, with underscores
 681          */
 682         public function getDBkey() {
 683                 return $this->mDbkeyform;
 684         }
 685
 686         /**
 687          * Get the DB key with the initial letter case as specified by the user
 688          *
 689          * @return String DB key
 690          */
 691         function getUserCaseDBKey() {
 692                 return $this->mUserCaseDBKey;
 693         }
 694
 695         /**
 696          * Get the namespace index, i.e. one of the NS_xxxx constants.
 697          *
 698          * @return Integer: Namespace index
 699          */
 700         public function getNamespace() {
 701                 return $this->mNamespace;
 702         }
 703
 704         /**
 705          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 706          *
 707          * @return Integer: Content model id
 708          */
 709         public function getContentModel() {
 710                 if ( empty( $this->mContentModel ) ) {
 711                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 712                 }
 713
 714                 assert( !empty( $this->mContentModel ) );
 715                 return $this->mContentModel;
 716         }
 717
 718         /**
 719          * Conveniance method for checking a title's content model name
 720          *
 721          * @param int $id
 722          * @return true if $this->getContentModel() == $id
 723          */
 724         public function hasContentModel( $id ) {
 725                 return $this->getContentModel() == $id;
 726         }
 727
 728         /**
 729          * Get the namespace text
 730          *
 731          * @return String: Namespace text
 732          */
 733         public function getNsText() {
 734                 global $wgContLang;
 735
 736                 if ( $this->mInterwiki != '' ) {
 737                         // This probably shouldn't even happen. ohh man, oh yuck.
 738                         // But for interwiki transclusion it sometimes does.
 739                         // Shit. Shit shit shit.
 740                         //
 741                         // Use the canonical namespaces if possible to try to
 742                         // resolve a foreign namespace.
 743                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 744                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 745                         }
 746                 }
 747
 748                 if ( $wgContLang->needsGenderDistinction() &&
 749                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 750                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 751                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 752                 }
 753
 754                 return $wgContLang->getNsText( $this->mNamespace );
 755         }
 756
 757         /**
 758          * Get the namespace text of the subject (rather than talk) page
 759          *
 760          * @return String Namespace text
 761          */
 762         public function getSubjectNsText() {
 763                 global $wgContLang;
 764                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 765         }
 766
 767         /**
 768          * Get the namespace text of the talk page
 769          *
 770          * @return String Namespace text
 771          */
 772         public function getTalkNsText() {
 773                 global $wgContLang;
 774                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 775         }
 776
 777         /**
 778          * Could this title have a corresponding talk page?
 779          *
 780          * @return Bool TRUE or FALSE
 781          */
 782         public function canTalk() {
 783                 return( MWNamespace::canTalk( $this->mNamespace ) );
 784         }
 785
 786         /**
 787          * Is this in a namespace that allows actual pages?
 788          *
 789          * @return Bool
 790          * @internal note -- uses hardcoded namespace index instead of constants
 791          */
 792         public function canExist() {
 793                 return $this->mNamespace >= NS_MAIN;
 794         }
 795
 796         /**
 797          * Can this title be added to a user's watchlist?
 798          *
 799          * @return Bool TRUE or FALSE
 800          */
 801         public function isWatchable() {
 802                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 803         }
 804
 805         /**
 806          * Returns true if this is a special page.
 807          *
 808          * @return boolean
 809          */
 810         public function isSpecialPage() {
 811                 return $this->getNamespace() == NS_SPECIAL;
 812         }
 813
 814         /**
 815          * Returns true if this title resolves to the named special page
 816          *
 817          * @param $name String The special page name
 818          * @return boolean
 819          */
 820         public function isSpecial( $name ) {
 821                 if ( $this->isSpecialPage() ) {
 822                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 823                         if ( $name == $thisName ) {
 824                                 return true;
 825                         }
 826                 }
 827                 return false;
 828         }
 829
 830         /**
 831          * If the Title refers to a special page alias which is not the local default, resolve
 832          * the alias, and localise the name as necessary.  Otherwise, return $this
 833          *
 834          * @return Title
 835          */
 836         public function fixSpecialName() {
 837                 if ( $this->isSpecialPage() ) {
 838                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 839                         if ( $canonicalName ) {
 840                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 841                                 if ( $localName != $this->mDbkeyform ) {
 842                                         return Title::makeTitle( NS_SPECIAL, $localName );
 843                                 }
 844                         }
 845                 }
 846                 return $this;
 847         }
 848
 849         /**
 850          * Returns true if the title is inside the specified namespace.
 851          *
 852          * Please make use of this instead of comparing to getNamespace()
 853          * This function is much more resistant to changes we may make
 854          * to namespaces than code that makes direct comparisons.
 855          * @param $ns int The namespace
 856          * @return bool
 857          * @since 1.19
 858          */
 859         public function inNamespace( $ns ) {
 860                 return MWNamespace::equals( $this->getNamespace(), $ns );
 861         }
 862
 863         /**
 864          * Returns true if the title is inside one of the specified namespaces.
 865          *
 866          * @param ...$namespaces The namespaces to check for
 867          * @return bool
 868          * @since 1.19
 869          */
 870         public function inNamespaces( /* ... */ ) {
 871                 $namespaces = func_get_args();
 872                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 873                         $namespaces = $namespaces[0];
 874                 }
 875
 876                 foreach ( $namespaces as $ns ) {
 877                         if ( $this->inNamespace( $ns ) ) {
 878                                 return true;
 879                         }
 880                 }
 881
 882                 return false;
 883         }
 884
 885         /**
 886          * Returns true if the title has the same subject namespace as the
 887          * namespace specified.
 888          * For example this method will take NS_USER and return true if namespace
 889          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 890          * as their subject namespace.
 891          *
 892          * This is MUCH simpler than individually testing for equivilance
 893          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 894          * @since 1.19
 895          * @param $ns int
 896          * @return bool
 897          */
 898         public function hasSubjectNamespace( $ns ) {
 899                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 900         }
 901
 902         /**
 903          * Is this Title in a namespace which contains content?
 904          * In other words, is this a content page, for the purposes of calculating
 905          * statistics, etc?
 906          *
 907          * @return Boolean
 908          */
 909         public function isContentPage() {
 910                 return MWNamespace::isContent( $this->getNamespace() );
 911         }
 912
 913         /**
 914          * Would anybody with sufficient privileges be able to move this page?
 915          * Some pages just aren't movable.
 916          *
 917          * @return Bool TRUE or FALSE
 918          */
 919         public function isMovable() {
 920                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 921                         // Interwiki title or immovable namespace. Hooks don't get to override here
 922                         return false;
 923                 }
 924
 925                 $result = true;
 926                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 927                 return $result;
 928         }
 929
 930         /**
 931          * Is this the mainpage?
 932          * @note Title::newFromText seams to be sufficiently optimized by the title
 933          * cache that we don't need to over-optimize by doing direct comparisons and
 934          * acidentally creating new bugs where $title->equals( Title::newFromText() )
 935          * ends up reporting something differently than $title->isMainPage();
 936          *
 937          * @since 1.18
 938          * @return Bool
 939          */
 940         public function isMainPage() {
 941                 return $this->equals( Title::newMainPage() );
 942         }
 943
 944         /**
 945          * Is this a subpage?
 946          *
 947          * @return Bool
 948          */
 949         public function isSubpage() {
 950                 return MWNamespace::hasSubpages( $this->mNamespace )
 951                         ? strpos( $this->getText(), '/' ) !== false
 952                         : false;
 953         }
 954
 955         /**
 956          * Is this a conversion table for the LanguageConverter?
 957          *
 958          * @return Bool
 959          */
 960         public function isConversionTable() {
 961                 return $this->getNamespace() == NS_MEDIAWIKI &&
 962                         strpos( $this->getText(), 'Conversiontable' ) !== false;
 963         }
 964
 965         /**
 966          * Does that page contain wikitext, or it is JS, CSS or whatever?
 967          *
 968          * @return Bool
 969          */
 970         public function isWikitextPage() {
 971                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
 972         }
 973
 974         /**
 975          * Could this page contain custom CSS or JavaScript for the global UI.
 976          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
 977          * or CONTENT_MODEL_JAVASCRIPT.
 978          *
 979          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
 980          *
 981          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
 982          *
 983          * @return Bool
 984          */
 985         public function isCssOrJsPage() {
 986                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
 987                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 988                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
 989
 990                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
 991                 #      hook funktions can force this method to return true even outside the mediawiki namespace.
 992
 993                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
 994
 995                 return $isCssOrJsPage;
 996         }
 997
 998         /**
 999          * Is this a .css or .js subpage of a user page?
1000          * @return Bool
1001          */
1002         public function isCssJsSubpage() {
1003                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1004                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
1005                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
1006         }
1007
1008         /**
1009          * Trim down a .css or .js subpage title to get the corresponding skin name
1010          *
1011          * @return string containing skin name from .css or .js subpage title
1012          */
1013         public function getSkinFromCssJsSubpage() {
1014                 $subpage = explode( '/', $this->mTextform );
1015                 $subpage = $subpage[ count( $subpage ) - 1 ];
1016                 $lastdot = strrpos( $subpage, '.' );
1017                 if ( $lastdot === false )
1018                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1019                 return substr( $subpage, 0, $lastdot );
1020         }
1021
1022         /**
1023          * Is this a .css subpage of a user page?
1024          *
1025          * @return Bool
1026          */
1027         public function isCssSubpage() {
1028                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1029                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1030         }
1031
1032         /**
1033          * Is this a .js subpage of a user page?
1034          *
1035          * @return Bool
1036          */
1037         public function isJsSubpage() {
1038                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1039                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1040         }
1041
1042         /**
1043          * Is this a talk page of some sort?
1044          *
1045          * @return Bool
1046          */
1047         public function isTalkPage() {
1048                 return MWNamespace::isTalk( $this->getNamespace() );
1049         }
1050
1051         /**
1052          * Get a Title object associated with the talk page of this article
1053          *
1054          * @return Title the object for the talk page
1055          */
1056         public function getTalkPage() {
1057                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1058         }
1059
1060         /**
1061          * Get a title object associated with the subject page of this
1062          * talk page
1063          *
1064          * @return Title the object for the subject page
1065          */
1066         public function getSubjectPage() {
1067                 // Is this the same title?
1068                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1069                 if ( $this->getNamespace() == $subjectNS ) {
1070                         return $this;
1071                 }
1072                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1073         }
1074
1075         /**
1076          * Get the default namespace index, for when there is no namespace
1077          *
1078          * @return Int Default namespace index
1079          */
1080         public function getDefaultNamespace() {
1081                 return $this->mDefaultNamespace;
1082         }
1083
1084         /**
1085          * Get title for search index
1086          *
1087          * @return String a stripped-down title string ready for the
1088          *  search index
1089          */
1090         public function getIndexTitle() {
1091                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1092         }
1093
1094         /**
1095          * Get the Title fragment (i.e.\ the bit after the #) in text form
1096          *
1097          * @return String Title fragment
1098          */
1099         public function getFragment() {
1100                 return $this->mFragment;
1101         }
1102
1103         /**
1104          * Get the fragment in URL form, including the "#" character if there is one
1105          * @return String Fragment in URL form
1106          */
1107         public function getFragmentForURL() {
1108                 if ( $this->mFragment == '' ) {
1109                         return '';
1110                 } else {
1111                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1112                 }
1113         }
1114
1115         /**
1116          * Set the fragment for this title. Removes the first character from the
1117          * specified fragment before setting, so it assumes you're passing it with
1118          * an initial "#".
1119          *
1120          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1121          * Still in active use privately.
1122          *
1123          * @param $fragment String text
1124          */
1125         public function setFragment( $fragment ) {
1126                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1127         }
1128
1129         /**
1130          * Prefix some arbitrary text with the namespace or interwiki prefix
1131          * of this object
1132          *
1133          * @param $name String the text
1134          * @return String the prefixed text
1135          * @private
1136          */
1137         private function prefix( $name ) {
1138                 $p = '';
1139                 if ( $this->mInterwiki != '' ) {
1140                         $p = $this->mInterwiki . ':';
1141                 }
1142
1143                 if ( 0 != $this->mNamespace ) {
1144                         $p .= $this->getNsText() . ':';
1145                 }
1146                 return $p . $name;
1147         }
1148
1149         /**
1150          * Get the prefixed database key form
1151          *
1152          * @return String the prefixed title, with underscores and
1153          *  any interwiki and namespace prefixes
1154          */
1155         public function getPrefixedDBkey() {
1156                 $s = $this->prefix( $this->mDbkeyform );
1157                 $s = str_replace( ' ', '_', $s );
1158                 return $s;
1159         }
1160
1161         /**
1162          * Get the prefixed title with spaces.
1163          * This is the form usually used for display
1164          *
1165          * @return String the prefixed title, with spaces
1166          */
1167         public function getPrefixedText() {
1168                 // @todo FIXME: Bad usage of empty() ?
1169                 if ( empty( $this->mPrefixedText ) ) {
1170                         $s = $this->prefix( $this->mTextform );
1171                         $s = str_replace( '_', ' ', $s );
1172                         $this->mPrefixedText = $s;
1173                 }
1174                 return $this->mPrefixedText;
1175         }
1176
1177         /**
1178          * Return a string representation of this title
1179          *
1180          * @return String representation of this title
1181          */
1182         public function __toString() {
1183                 return $this->getPrefixedText();
1184         }
1185
1186         /**
1187          * Get the prefixed title with spaces, plus any fragment
1188          * (part beginning with '#')
1189          *
1190          * @return String the prefixed title, with spaces and the fragment, including '#'
1191          */
1192         public function getFullText() {
1193                 $text = $this->getPrefixedText();
1194                 if ( $this->mFragment != '' ) {
1195                         $text .= '#' . $this->mFragment;
1196                 }
1197                 return $text;
1198         }
1199
1200         /**
1201          * Get the base page name, i.e. the leftmost part before any slashes
1202          *
1203          * @return String Base name
1204          */
1205         public function getBaseText() {
1206                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1207                         return $this->getText();
1208                 }
1209
1210                 $parts = explode( '/', $this->getText() );
1211                 # Don't discard the real title if there's no subpage involved
1212                 if ( count( $parts ) > 1 ) {
1213                         unset( $parts[count( $parts ) - 1] );
1214                 }
1215                 return implode( '/', $parts );
1216         }
1217
1218         /**
1219          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1220          *
1221          * @return String Subpage name
1222          */
1223         public function getSubpageText() {
1224                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1225                         return( $this->mTextform );
1226                 }
1227                 $parts = explode( '/', $this->mTextform );
1228                 return( $parts[count( $parts ) - 1] );
1229         }
1230
1231         /**
1232          * Get the HTML-escaped displayable text form.
1233          * Used for the title field in <a> tags.
1234          *
1235          * @return String the text, including any prefixes
1236          */
1237         public function getEscapedText() {
1238                 wfDeprecated( __METHOD__, '1.19' );
1239                 return htmlspecialchars( $this->getPrefixedText() );
1240         }
1241
1242         /**
1243          * Get a URL-encoded form of the subpage text
1244          *
1245          * @return String URL-encoded subpage name
1246          */
1247         public function getSubpageUrlForm() {
1248                 $text = $this->getSubpageText();
1249                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1250                 return( $text );
1251         }
1252
1253         /**
1254          * Get a URL-encoded title (not an actual URL) including interwiki
1255          *
1256          * @return String the URL-encoded form
1257          */
1258         public function getPrefixedURL() {
1259                 $s = $this->prefix( $this->mDbkeyform );
1260                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1261                 return $s;
1262         }
1263
1264         /**
1265          * Helper to fix up the get{Local,Full,Link,Canonical}URL args
1266          * get{Canonical,Full,Link,Local}URL methods accepted an optional
1267          * second argument named variant. This was deprecated in favor
1268          * of passing an array of option with a "variant" key
1269          * Once $query2 is removed for good, this helper can be dropped
1270          * andthe wfArrayToCGI moved to getLocalURL();
1271          *
1272          * @since 1.19 (r105919)
1273          * @param $query
1274          * @param $query2 bool
1275          * @return String
1276          */
1277         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1278                 if( $query2 !== false ) {
1279                         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" );
1280                 }
1281                 if ( is_array( $query ) ) {
1282                         $query = wfArrayToCGI( $query );
1283                 }
1284                 if ( $query2 ) {
1285                         if ( is_string( $query2 ) ) {
1286                                 // $query2 is a string, we will consider this to be
1287                                 // a deprecated $variant argument and add it to the query
1288                                 $query2 = wfArrayToCGI( array( 'variant' => $query2 ) );
1289                         } else {
1290                                 $query2 = wfArrayToCGI( $query2 );
1291                         }
1292                         // If we have $query content add a & to it first
1293                         if ( $query ) {
1294                                 $query .= '&';
1295                         }
1296                         // Now append the queries together
1297                         $query .= $query2;
1298                 }
1299                 return $query;
1300         }
1301
1302         /**
1303          * Get a real URL referring to this title, with interwiki link and
1304          * fragment
1305          *
1306          * See getLocalURL for the arguments.
1307          *
1308          * @see self::getLocalURL
1309          * @return String the URL
1310          */
1311         public function getFullURL( $query = '', $query2 = false ) {
1312                 $query = self::fixUrlQueryArgs( $query, $query2 );
1313
1314                 # Hand off all the decisions on urls to getLocalURL
1315                 $url = $this->getLocalURL( $query );
1316
1317                 # Expand the url to make it a full url. Note that getLocalURL has the
1318                 # potential to output full urls for a variety of reasons, so we use
1319                 # wfExpandUrl instead of simply prepending $wgServer
1320                 $url = wfExpandUrl( $url, PROTO_RELATIVE );
1321
1322                 # Finally, add the fragment.
1323                 $url .= $this->getFragmentForURL();
1324
1325                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1326                 return $url;
1327         }
1328
1329         /**
1330          * Get a URL with no fragment or server name.  If this page is generated
1331          * with action=render, $wgServer is prepended.
1332          *
1333
1334          * @param $query string|array an optional query string,
1335          *   not used for interwiki     links. Can be specified as an associative array as well,
1336          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1337          *   Some query patterns will trigger various shorturl path replacements.
1338          * @param $query2 Mixed: An optional secondary query array. This one MUST
1339          *   be an array. If a string is passed it will be interpreted as a deprecated
1340          *   variant argument and urlencoded into a variant= argument.
1341          *   This second query argument will be added to the $query
1342          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1343          *   pair in the first parameter array instead.
1344          *
1345          * @return String the URL
1346          */
1347         public function getLocalURL( $query = '', $query2 = false ) {
1348                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1349
1350                 $query = self::fixUrlQueryArgs( $query, $query2 );
1351
1352                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1353                 if ( $interwiki ) {
1354                         $namespace = $this->getNsText();
1355                         if ( $namespace != '' ) {
1356                                 # Can this actually happen? Interwikis shouldn't be parsed.
1357                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1358                                 $namespace .= ':';
1359                         }
1360                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1361                         $url = wfAppendQuery( $url, $query );
1362                 } else {
1363                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1364                         if ( $query == '' ) {
1365                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1366                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1367                         } else {
1368                                 global $wgVariantArticlePath, $wgActionPaths;
1369                                 $url = false;
1370                                 $matches = array();
1371
1372                                 if ( !empty( $wgActionPaths ) &&
1373                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1374                                 {
1375                                         $action = urldecode( $matches[2] );
1376                                         if ( isset( $wgActionPaths[$action] ) ) {
1377                                                 $query = $matches[1];
1378                                                 if ( isset( $matches[4] ) ) {
1379                                                         $query .= $matches[4];
1380                                                 }
1381                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1382                                                 if ( $query != '' ) {
1383                                                         $url = wfAppendQuery( $url, $query );
1384                                                 }
1385                                         }
1386                                 }
1387
1388                                 if ( $url === false &&
1389                                         $wgVariantArticlePath &&
1390                                         $this->getPageLanguage()->hasVariants() &&
1391                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1392                                 {
1393                                         $variant = urldecode( $matches[1] );
1394                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1395                                                 // Only do the variant replacement if the given variant is a valid
1396                                                 // variant for the page's language.
1397                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1398                                                 $url = str_replace( '$1', $dbkey, $url );
1399                                         }
1400                                 }
1401
1402                                 if ( $url === false ) {
1403                                         if ( $query == '-' ) {
1404                                                 $query = '';
1405                                         }
1406                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1407                                 }
1408                         }
1409
1410                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1411
1412                         // @todo FIXME: This causes breakage in various places when we
1413                         // actually expected a local URL and end up with dupe prefixes.
1414                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1415                                 $url = $wgServer . $url;
1416                         }
1417                 }
1418                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1419                 return $url;
1420         }
1421
1422         /**
1423          * Get a URL that's the simplest URL that will be valid to link, locally,
1424          * to the current Title.  It includes the fragment, but does not include
1425          * the server unless action=render is used (or the link is external).  If
1426          * there's a fragment but the prefixed text is empty, we just return a link
1427          * to the fragment.
1428          *
1429          * The result obviously should not be URL-escaped, but does need to be
1430          * HTML-escaped if it's being output in HTML.
1431          *
1432          * See getLocalURL for the arguments.
1433          *
1434          * @see self::getLocalURL
1435          * @return String the URL
1436          */
1437         public function getLinkURL( $query = '', $query2 = false ) {
1438                 wfProfileIn( __METHOD__ );
1439                 if ( $this->isExternal() ) {
1440                         $ret = $this->getFullURL( $query, $query2 );
1441                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1442                         $ret = $this->getFragmentForURL();
1443                 } else {
1444                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1445                 }
1446                 wfProfileOut( __METHOD__ );
1447                 return $ret;
1448         }
1449
1450         /**
1451          * Get an HTML-escaped version of the URL form, suitable for
1452          * using in a link, without a server name or fragment
1453          *
1454          * See getLocalURL for the arguments.
1455          *
1456          * @see self::getLocalURL
1457          * @param $query string
1458          * @param $query2 bool|string
1459          * @return String the URL
1460          */
1461         public function escapeLocalURL( $query = '', $query2 = false ) {
1462                 wfDeprecated( __METHOD__, '1.19' );
1463                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1464         }
1465
1466         /**
1467          * Get an HTML-escaped version of the URL form, suitable for
1468          * using in a link, including the server name and fragment
1469          *
1470          * See getLocalURL for the arguments.
1471          *
1472          * @see self::getLocalURL
1473          * @return String the URL
1474          */
1475         public function escapeFullURL( $query = '', $query2 = false ) {
1476                 wfDeprecated( __METHOD__, '1.19' );
1477                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1478         }
1479
1480         /**
1481          * Get the URL form for an internal link.
1482          * - Used in various Squid-related code, in case we have a different
1483          * internal hostname for the server from the exposed one.
1484          *
1485          * This uses $wgInternalServer to qualify the path, or $wgServer
1486          * if $wgInternalServer is not set. If the server variable used is
1487          * protocol-relative, the URL will be expanded to http://
1488          *
1489          * See getLocalURL for the arguments.
1490          *
1491          * @see self::getLocalURL
1492          * @return String the URL
1493          */
1494         public function getInternalURL( $query = '', $query2 = false ) {
1495                 global $wgInternalServer, $wgServer;
1496                 $query = self::fixUrlQueryArgs( $query, $query2 );
1497                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1498                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1499                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1500                 return $url;
1501         }
1502
1503         /**
1504          * Get the URL for a canonical link, for use in things like IRC and
1505          * e-mail notifications. Uses $wgCanonicalServer and the
1506          * GetCanonicalURL hook.
1507          *
1508          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1509          *
1510          * See getLocalURL for the arguments.
1511          *
1512          * @see self::getLocalURL
1513          * @return string The URL
1514          * @since 1.18
1515          */
1516         public function getCanonicalURL( $query = '', $query2 = false ) {
1517                 $query = self::fixUrlQueryArgs( $query, $query2 );
1518                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1519                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1520                 return $url;
1521         }
1522
1523         /**
1524          * HTML-escaped version of getCanonicalURL()
1525          *
1526          * See getLocalURL for the arguments.
1527          *
1528          * @see self::getLocalURL
1529          * @since 1.18
1530          * @return string
1531          */
1532         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1533                 wfDeprecated( __METHOD__, '1.19' );
1534                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1535         }
1536
1537         /**
1538          * Get the edit URL for this Title
1539          *
1540          * @return String the URL, or a null string if this is an
1541          *  interwiki link
1542          */
1543         public function getEditURL() {
1544                 if ( $this->mInterwiki != '' ) {
1545                         return '';
1546                 }
1547                 $s = $this->getLocalURL( 'action=edit' );
1548
1549                 return $s;
1550         }
1551
1552         /**
1553          * Is $wgUser watching this page?
1554          *
1555          * @return Bool
1556          */
1557         public function userIsWatching() {
1558                 global $wgUser;
1559
1560                 if ( is_null( $this->mWatched ) ) {
1561                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1562                                 $this->mWatched = false;
1563                         } else {
1564                                 $this->mWatched = $wgUser->isWatched( $this );
1565                         }
1566                 }
1567                 return $this->mWatched;
1568         }
1569
1570         /**
1571          * Can $wgUser read this page?
1572          *
1573          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1574          * @return Bool
1575          * @todo fold these checks into userCan()
1576          */
1577         public function userCanRead() {
1578                 wfDeprecated( __METHOD__, '1.19' );
1579                 return $this->userCan( 'read' );
1580         }
1581
1582         /**
1583          * Can $user perform $action on this page?
1584          * This skips potentially expensive cascading permission checks
1585          * as well as avoids expensive error formatting
1586          *
1587          * Suitable for use for nonessential UI controls in common cases, but
1588          * _not_ for functional access control.
1589          *
1590          * May provide false positives, but should never provide a false negative.
1591          *
1592          * @param $action String action that permission needs to be checked for
1593          * @param $user User to check (since 1.19); $wgUser will be used if not
1594          *              provided.
1595          * @return Bool
1596          */
1597         public function quickUserCan( $action, $user = null ) {
1598                 return $this->userCan( $action, $user, false );
1599         }
1600
1601         /**
1602          * Can $user perform $action on this page?
1603          *
1604          * @param $action String action that permission needs to be checked for
1605          * @param $user User to check (since 1.19); $wgUser will be used if not
1606          *   provided.
1607          * @param $doExpensiveQueries Bool Set this to false to avoid doing
1608          *   unnecessary queries.
1609          * @return Bool
1610          */
1611         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1612                 if ( !$user instanceof User ) {
1613                         global $wgUser;
1614                         $user = $wgUser;
1615                 }
1616                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1617         }
1618
1619         /**
1620          * Can $user perform $action on this page?
1621          *
1622          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1623          *
1624          * @param $action String action that permission needs to be checked for
1625          * @param $user User to check
1626          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary
1627          *   queries by skipping checks for cascading protections and user blocks.
1628          * @param $ignoreErrors Array of Strings Set this to a list of message keys
1629          *   whose corresponding errors may be ignored.
1630          * @return Array of arguments to wfMsg to explain permissions problems.
1631          */
1632         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1633                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1634
1635                 // Remove the errors being ignored.
1636                 foreach ( $errors as $index => $error ) {
1637                         $error_key = is_array( $error ) ? $error[0] : $error;
1638
1639                         if ( in_array( $error_key, $ignoreErrors ) ) {
1640                                 unset( $errors[$index] );
1641                         }
1642                 }
1643
1644                 return $errors;
1645         }
1646
1647         /**
1648          * Permissions checks that fail most often, and which are easiest to test.
1649          *
1650          * @param $action String the action to check
1651          * @param $user User user to check
1652          * @param $errors Array list of current errors
1653          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1654          * @param $short Boolean short circuit on first error
1655          *
1656          * @return Array list of errors
1657          */
1658         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1659                 if ( $action == 'create' ) {
1660                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1661                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1662                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1663                         }
1664                 } elseif ( $action == 'move' ) {
1665                         if ( !$user->isAllowed( 'move-rootuserpages' )
1666                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1667                                 // Show user page-specific message only if the user can move other pages
1668                                 $errors[] = array( 'cant-move-user-page' );
1669                         }
1670
1671                         // Check if user is allowed to move files if it's a file
1672                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1673                                 $errors[] = array( 'movenotallowedfile' );
1674                         }
1675
1676                         if ( !$user->isAllowed( 'move' ) ) {
1677                                 // User can't move anything
1678                                 global $wgGroupPermissions;
1679                                 $userCanMove = false;
1680                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1681                                         $userCanMove = $wgGroupPermissions['user']['move'];
1682                                 }
1683                                 $autoconfirmedCanMove = false;
1684                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1685                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1686                                 }
1687                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1688                                         // custom message if logged-in users without any special rights can move
1689                                         $errors[] = array( 'movenologintext' );
1690                                 } else {
1691                                         $errors[] = array( 'movenotallowed' );
1692                                 }
1693                         }
1694                 } elseif ( $action == 'move-target' ) {
1695                         if ( !$user->isAllowed( 'move' ) ) {
1696                                 // User can't move anything
1697                                 $errors[] = array( 'movenotallowed' );
1698                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1699                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1700                                 // Show user page-specific message only if the user can move other pages
1701                                 $errors[] = array( 'cant-move-to-user-page' );
1702                         }
1703                 } elseif ( !$user->isAllowed( $action ) ) {
1704                         $errors[] = $this->missingPermissionError( $action, $short );
1705                 }
1706
1707                 return $errors;
1708         }
1709
1710         /**
1711          * Add the resulting error code to the errors array
1712          *
1713          * @param $errors Array list of current errors
1714          * @param $result Mixed result of errors
1715          *
1716          * @return Array list of errors
1717          */
1718         private function resultToError( $errors, $result ) {
1719                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1720                         // A single array representing an error
1721                         $errors[] = $result;
1722                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1723                         // A nested array representing multiple errors
1724                         $errors = array_merge( $errors, $result );
1725                 } elseif ( $result !== '' && is_string( $result ) ) {
1726                         // A string representing a message-id
1727                         $errors[] = array( $result );
1728                 } elseif ( $result === false ) {
1729                         // a generic "We don't want them to do that"
1730                         $errors[] = array( 'badaccess-group0' );
1731                 }
1732                 return $errors;
1733         }
1734
1735         /**
1736          * Check various permission hooks
1737          *
1738          * @param $action String the action to check
1739          * @param $user User user to check
1740          * @param $errors Array list of current errors
1741          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1742          * @param $short Boolean short circuit on first error
1743          *
1744          * @return Array list of errors
1745          */
1746         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1747                 // Use getUserPermissionsErrors instead
1748                 $result = '';
1749                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1750                         return $result ? array() : array( array( 'badaccess-group0' ) );
1751                 }
1752                 // Check getUserPermissionsErrors hook
1753                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1754                         $errors = $this->resultToError( $errors, $result );
1755                 }
1756                 // Check getUserPermissionsErrorsExpensive hook
1757                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1758                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1759                         $errors = $this->resultToError( $errors, $result );
1760                 }
1761
1762                 return $errors;
1763         }
1764
1765         /**
1766          * Check permissions on special pages & namespaces
1767          *
1768          * @param $action String the action to check
1769          * @param $user User user to check
1770          * @param $errors Array list of current errors
1771          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1772          * @param $short Boolean short circuit on first error
1773          *
1774          * @return Array list of errors
1775          */
1776         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1777                 # Only 'createaccount' and 'execute' can be performed on
1778                 # special pages, which don't actually exist in the DB.
1779                 $specialOKActions = array( 'createaccount', 'execute', 'read' );
1780                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1781                         $errors[] = array( 'ns-specialprotected' );
1782                 }
1783
1784                 # Check $wgNamespaceProtection for restricted namespaces
1785                 if ( $this->isNamespaceProtected( $user ) ) {
1786                         $ns = $this->mNamespace == NS_MAIN ?
1787                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1788                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1789                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1790                 }
1791
1792                 return $errors;
1793         }
1794
1795         /**
1796          * Check CSS/JS sub-page permissions
1797          *
1798          * @param $action String the action to check
1799          * @param $user User user to check
1800          * @param $errors Array list of current errors
1801          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1802          * @param $short Boolean short circuit on first error
1803          *
1804          * @return Array list of errors
1805          */
1806         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1807                 # Protect css/js subpages of user pages
1808                 # XXX: this might be better using restrictions
1809                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1810                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1811                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1812                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1813                                 $errors[] = array( 'customcssprotected' );
1814                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1815                                 $errors[] = array( 'customjsprotected' );
1816                         }
1817                 }
1818
1819                 return $errors;
1820         }
1821
1822         /**
1823          * Check against page_restrictions table requirements on this
1824          * page. The user must possess all required rights for this
1825          * action.
1826          *
1827          * @param $action String the action to check
1828          * @param $user User user to check
1829          * @param $errors Array list of current errors
1830          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1831          * @param $short Boolean short circuit on first error
1832          *
1833          * @return Array list of errors
1834          */
1835         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1836                 foreach ( $this->getRestrictions( $action ) as $right ) {
1837                         // Backwards compatibility, rewrite sysop -> protect
1838                         if ( $right == 'sysop' ) {
1839                                 $right = 'protect';
1840                         }
1841                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1842                                 // Users with 'editprotected' permission can edit protected pages
1843                                 // without cascading option turned on.
1844                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1845                                         || $this->mCascadeRestriction )
1846                                 {
1847                                         $errors[] = array( 'protectedpagetext', $right );
1848                                 }
1849                         }
1850                 }
1851
1852                 return $errors;
1853         }
1854
1855         /**
1856          * Check restrictions on cascading pages.
1857          *
1858          * @param $action String the action to check
1859          * @param $user User to check
1860          * @param $errors Array list of current errors
1861          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1862          * @param $short Boolean short circuit on first error
1863          *
1864          * @return Array list of errors
1865          */
1866         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1867                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1868                         # We /could/ use the protection level on the source page, but it's
1869                         # fairly ugly as we have to establish a precedence hierarchy for pages
1870                         # included by multiple cascade-protected pages. So just restrict
1871                         # it to people with 'protect' permission, as they could remove the
1872                         # protection anyway.
1873                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1874                         # Cascading protection depends on more than this page...
1875                         # Several cascading protected pages may include this page...
1876                         # Check each cascading level
1877                         # This is only for protection restrictions, not for all actions
1878                         if ( isset( $restrictions[$action] ) ) {
1879                                 foreach ( $restrictions[$action] as $right ) {
1880                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1881                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1882                                                 $pages = '';
1883                                                 foreach ( $cascadingSources as $page )
1884                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1885                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1886                                         }
1887                                 }
1888                         }
1889                 }
1890
1891                 return $errors;
1892         }
1893
1894         /**
1895          * Check action permissions not already checked in checkQuickPermissions
1896          *
1897          * @param $action String the action to check
1898          * @param $user User to check
1899          * @param $errors Array list of current errors
1900          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1901          * @param $short Boolean short circuit on first error
1902          *
1903          * @return Array list of errors
1904          */
1905         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1906                 global $wgDeleteRevisionsLimit, $wgLang;
1907
1908                 if ( $action == 'protect' ) {
1909                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1910                                 // If they can't edit, they shouldn't protect.
1911                                 $errors[] = array( 'protect-cantedit' );
1912                         }
1913                 } elseif ( $action == 'create' ) {
1914                         $title_protection = $this->getTitleProtection();
1915                         if( $title_protection ) {
1916                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1917                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1918                                 }
1919                                 if( $title_protection['pt_create_perm'] == '' ||
1920                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1921                                 {
1922                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1923                                 }
1924                         }
1925                 } elseif ( $action == 'move' ) {
1926                         // Check for immobile pages
1927                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1928                                 // Specific message for this case
1929                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1930                         } elseif ( !$this->isMovable() ) {
1931                                 // Less specific message for rarer cases
1932                                 $errors[] = array( 'immobile-source-page' );
1933                         }
1934                 } elseif ( $action == 'move-target' ) {
1935                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1936                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1937                         } elseif ( !$this->isMovable() ) {
1938                                 $errors[] = array( 'immobile-target-page' );
1939                         }
1940                 } elseif ( $action == 'delete' ) {
1941                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
1942                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
1943                         {
1944                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
1945                         }
1946                 }
1947                 return $errors;
1948         }
1949
1950         /**
1951          * Check that the user isn't blocked from editting.
1952          *
1953          * @param $action String the action to check
1954          * @param $user User to check
1955          * @param $errors Array list of current errors
1956          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1957          * @param $short Boolean short circuit on first error
1958          *
1959          * @return Array list of errors
1960          */
1961         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1962                 // Account creation blocks handled at userlogin.
1963                 // Unblocking handled in SpecialUnblock
1964                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
1965                         return $errors;
1966                 }
1967
1968                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1969
1970                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
1971                         $errors[] = array( 'confirmedittext' );
1972                 }
1973
1974                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
1975                         // Don't block the user from editing their own talk page unless they've been
1976                         // explicitly blocked from that too.
1977                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1978                         $block = $user->getBlock();
1979
1980                         // This is from OutputPage::blockedPage
1981                         // Copied at r23888 by werdna
1982
1983                         $id = $user->blockedBy();
1984                         $reason = $user->blockedFor();
1985                         if ( $reason == '' ) {
1986                                 $reason = wfMsg( 'blockednoreason' );
1987                         }
1988                         $ip = $user->getRequest()->getIP();
1989
1990                         if ( is_numeric( $id ) ) {
1991                                 $name = User::whoIs( $id );
1992                         } else {
1993                                 $name = $id;
1994                         }
1995
1996                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1997                         $blockid = $block->getId();
1998                         $blockExpiry = $block->getExpiry();
1999                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
2000                         if ( $blockExpiry == 'infinity' ) {
2001                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
2002                         } else {
2003                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
2004                         }
2005
2006                         $intended = strval( $block->getTarget() );
2007
2008                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
2009                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
2010                 }
2011
2012                 return $errors;
2013         }
2014
2015         /**
2016          * Check that the user is allowed to read this page.
2017          *
2018          * @param $action String the action to check
2019          * @param $user User to check
2020          * @param $errors Array list of current errors
2021          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2022          * @param $short Boolean short circuit on first error
2023          *
2024          * @return Array list of errors
2025          */
2026         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2027                 global $wgWhitelistRead, $wgGroupPermissions, $wgRevokePermissions;
2028                 static $useShortcut = null;
2029
2030                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2031                 if ( is_null( $useShortcut ) ) {
2032                         $useShortcut = true;
2033                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
2034                                 # Not a public wiki, so no shortcut
2035                                 $useShortcut = false;
2036                         } elseif ( !empty( $wgRevokePermissions ) ) {
2037                                 /**
2038                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2039                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2040                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2041                                  * reading is allowed.
2042                                  */
2043                                 foreach ( $wgRevokePermissions as $perms ) {
2044                                         if ( !empty( $perms['read'] ) ) {
2045                                                 # We might be removing the read right from the user, so no shortcut
2046                                                 $useShortcut = false;
2047                                                 break;
2048                                         }
2049                                 }
2050                         }
2051                 }
2052
2053                 $whitelisted = false;
2054                 if ( $useShortcut ) {
2055                         # Shortcut for public wikis, allows skipping quite a bit of code
2056                         $whitelisted = true;
2057                 } elseif ( $user->isAllowed( 'read' ) ) {
2058                         # If the user is allowed to read pages, he is allowed to read all pages
2059                         $whitelisted = true;
2060                 } elseif ( $this->isSpecial( 'Userlogin' )
2061                         || $this->isSpecial( 'ChangePassword' )
2062                         || $this->isSpecial( 'PasswordReset' )
2063                 ) {
2064                         # Always grant access to the login page.
2065                         # Even anons need to be able to log in.
2066                         $whitelisted = true;
2067                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2068                         # Time to check the whitelist
2069                         # Only do these checks is there's something to check against
2070                         $name = $this->getPrefixedText();
2071                         $dbName = $this->getPrefixedDBKey();
2072
2073                         // Check for explicit whitelisting with and without underscores
2074                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2075                                 $whitelisted = true;
2076                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2077                                 # Old settings might have the title prefixed with
2078                                 # a colon for main-namespace pages
2079                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2080                                         $whitelisted = true;
2081                                 }
2082                         } elseif ( $this->isSpecialPage() ) {
2083                                 # If it's a special page, ditch the subpage bit and check again
2084                                 $name = $this->getDBkey();
2085                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2086                                 if ( $name !== false ) {
2087                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2088                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2089                                                 $whitelisted = true;
2090                                         }
2091                                 }
2092                         }
2093                 }
2094
2095                 if ( !$whitelisted ) {
2096                         # If the title is not whitelisted, give extensions a chance to do so...
2097                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2098                         if ( !$whitelisted ) {
2099                                 $errors[] = $this->missingPermissionError( $action, $short );
2100                         }
2101                 }
2102
2103                 return $errors;
2104         }
2105
2106         /**
2107          * Get a description array when the user doesn't have the right to perform
2108          * $action (i.e. when User::isAllowed() returns false)
2109          *
2110          * @param $action String the action to check
2111          * @param $short Boolean short circuit on first error
2112          * @return Array list of errors
2113          */
2114         private function missingPermissionError( $action, $short ) {
2115                 // We avoid expensive display logic for quickUserCan's and such
2116                 if ( $short ) {
2117                         return array( 'badaccess-group0' );
2118                 }
2119
2120                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2121                         User::getGroupsWithPermission( $action ) );
2122
2123                 if ( count( $groups ) ) {
2124                         global $wgLang;
2125                         return array(
2126                                 'badaccess-groups',
2127                                 $wgLang->commaList( $groups ),
2128                                 count( $groups )
2129                         );
2130                 } else {
2131                         return array( 'badaccess-group0' );
2132                 }
2133         }
2134
2135         /**
2136          * Can $user perform $action on this page? This is an internal function,
2137          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2138          * checks on wfReadOnly() and blocks)
2139          *
2140          * @param $action String action that permission needs to be checked for
2141          * @param $user User to check
2142          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
2143          * @param $short Bool Set this to true to stop after the first permission error.
2144          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
2145          */
2146         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2147                 wfProfileIn( __METHOD__ );
2148
2149                 # Read has special handling
2150                 if ( $action == 'read' ) {
2151                         $checks = array(
2152                                 'checkPermissionHooks',
2153                                 'checkReadPermissions',
2154                         );
2155                 } else {
2156                         $checks = array(
2157                                 'checkQuickPermissions',
2158                                 'checkPermissionHooks',
2159                                 'checkSpecialsAndNSPermissions',
2160                                 'checkCSSandJSPermissions',
2161                                 'checkPageRestrictions',
2162                                 'checkCascadingSourcesRestrictions',
2163                                 'checkActionPermissions',
2164                                 'checkUserBlock'
2165                         );
2166                 }
2167
2168                 $errors = array();
2169                 while( count( $checks ) > 0 &&
2170                                 !( $short && count( $errors ) > 0 ) ) {
2171                         $method = array_shift( $checks );
2172                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2173                 }
2174
2175                 wfProfileOut( __METHOD__ );
2176                 return $errors;
2177         }
2178
2179         /**
2180          * Protect css subpages of user pages: can $wgUser edit
2181          * this page?
2182          *
2183          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2184          * @return Bool
2185          */
2186         public function userCanEditCssSubpage() {
2187                 global $wgUser;
2188                 wfDeprecated( __METHOD__, '1.19' );
2189                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2190                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2191         }
2192
2193         /**
2194          * Protect js subpages of user pages: can $wgUser edit
2195          * this page?
2196          *
2197          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2198          * @return Bool
2199          */
2200         public function userCanEditJsSubpage() {
2201                 global $wgUser;
2202                 wfDeprecated( __METHOD__, '1.19' );
2203                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2204                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2205         }
2206
2207         /**
2208          * Get a filtered list of all restriction types supported by this wiki.
2209          * @param bool $exists True to get all restriction types that apply to
2210          * titles that do exist, False for all restriction types that apply to
2211          * titles that do not exist
2212          * @return array
2213          */
2214         public static function getFilteredRestrictionTypes( $exists = true ) {
2215                 global $wgRestrictionTypes;
2216                 $types = $wgRestrictionTypes;
2217                 if ( $exists ) {
2218                         # Remove the create restriction for existing titles
2219                         $types = array_diff( $types, array( 'create' ) );
2220                 } else {
2221                         # Only the create and upload restrictions apply to non-existing titles
2222                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2223                 }
2224                 return $types;
2225         }
2226
2227         /**
2228          * Returns restriction types for the current Title
2229          *
2230          * @return array applicable restriction types
2231          */
2232         public function getRestrictionTypes() {
2233                 if ( $this->isSpecialPage() ) {
2234                         return array();
2235                 }
2236
2237                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2238
2239                 if ( $this->getNamespace() != NS_FILE ) {
2240                         # Remove the upload restriction for non-file titles
2241                         $types = array_diff( $types, array( 'upload' ) );
2242                 }
2243
2244                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2245
2246                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2247                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2248
2249                 return $types;
2250         }
2251
2252         /**
2253          * Is this title subject to title protection?
2254          * Title protection is the one applied against creation of such title.
2255          *
2256          * @return Mixed An associative array representing any existent title
2257          *   protection, or false if there's none.
2258          */
2259         private function getTitleProtection() {
2260                 // Can't protect pages in special namespaces
2261                 if ( $this->getNamespace() < 0 ) {
2262                         return false;
2263                 }
2264
2265                 // Can't protect pages that exist.
2266                 if ( $this->exists() ) {
2267                         return false;
2268                 }
2269
2270                 if ( !isset( $this->mTitleProtection ) ) {
2271                         $dbr = wfGetDB( DB_SLAVE );
2272                         $res = $dbr->select( 'protected_titles', '*',
2273                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2274                                 __METHOD__ );
2275
2276                         // fetchRow returns false if there are no rows.
2277                         $this->mTitleProtection = $dbr->fetchRow( $res );
2278                 }
2279                 return $this->mTitleProtection;
2280         }
2281
2282         /**
2283          * Update the title protection status
2284          *
2285          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2286          * @param $create_perm String Permission required for creation
2287          * @param $reason String Reason for protection
2288          * @param $expiry String Expiry timestamp
2289          * @return boolean true
2290          */
2291         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2292                 wfDeprecated( __METHOD__, '1.19' );
2293
2294                 global $wgUser;
2295
2296                 $limit = array( 'create' => $create_perm );
2297                 $expiry = array( 'create' => $expiry );
2298
2299                 $page = WikiPage::factory( $this );
2300                 $status = $page->doUpdateRestrictions( $limit, $expiry, false, $reason, $wgUser );
2301
2302                 return $status->isOK();
2303         }
2304
2305         /**
2306          * Remove any title protection due to page existing
2307          */
2308         public function deleteTitleProtection() {
2309                 $dbw = wfGetDB( DB_MASTER );
2310
2311                 $dbw->delete(
2312                         'protected_titles',
2313                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2314                         __METHOD__
2315                 );
2316                 $this->mTitleProtection = false;
2317         }
2318
2319         /**
2320          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2321          *
2322          * @param $action String Action to check (default: edit)
2323          * @return Bool
2324          */
2325         public function isSemiProtected( $action = 'edit' ) {
2326                 if ( $this->exists() ) {
2327                         $restrictions = $this->getRestrictions( $action );
2328                         if ( count( $restrictions ) > 0 ) {
2329                                 foreach ( $restrictions as $restriction ) {
2330                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2331                                                 return false;
2332                                         }
2333                                 }
2334                         } else {
2335                                 # Not protected
2336                                 return false;
2337                         }
2338                         return true;
2339                 } else {
2340                         # If it doesn't exist, it can't be protected
2341                         return false;
2342                 }
2343         }
2344
2345         /**
2346          * Does the title correspond to a protected article?
2347          *
2348          * @param $action String the action the page is protected from,
2349          * by default checks all actions.
2350          * @return Bool
2351          */
2352         public function isProtected( $action = '' ) {
2353                 global $wgRestrictionLevels;
2354
2355                 $restrictionTypes = $this->getRestrictionTypes();
2356
2357                 # Special pages have inherent protection
2358                 if( $this->isSpecialPage() ) {
2359                         return true;
2360                 }
2361
2362                 # Check regular protection levels
2363                 foreach ( $restrictionTypes as $type ) {
2364                         if ( $action == $type || $action == '' ) {
2365                                 $r = $this->getRestrictions( $type );
2366                                 foreach ( $wgRestrictionLevels as $level ) {
2367                                         if ( in_array( $level, $r ) && $level != '' ) {
2368                                                 return true;
2369                                         }
2370                                 }
2371                         }
2372                 }
2373
2374                 return false;
2375         }
2376
2377         /**
2378          * Determines if $user is unable to edit this page because it has been protected
2379          * by $wgNamespaceProtection.
2380          *
2381          * @param $user User object to check permissions
2382          * @return Bool
2383          */
2384         public function isNamespaceProtected( User $user ) {
2385                 global $wgNamespaceProtection;
2386
2387                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2388                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2389                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2390                                         return true;
2391                                 }
2392                         }
2393                 }
2394                 return false;
2395         }
2396
2397         /**
2398          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2399          *
2400          * @return Bool If the page is subject to cascading restrictions.
2401          */
2402         public function isCascadeProtected() {
2403                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2404                 return ( $sources > 0 );
2405         }
2406
2407         /**
2408          * Cascading protection: Get the source of any cascading restrictions on this page.
2409          *
2410          * @param $getPages Bool Whether or not to retrieve the actual pages
2411          *        that the restrictions have come from.
2412          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2413          *     have come, false for none, or true if such restrictions exist, but $getPages
2414          *     was not set.  The restriction array is an array of each type, each of which
2415          *     contains a array of unique groups.
2416          */
2417         public function getCascadeProtectionSources( $getPages = true ) {
2418                 global $wgContLang;
2419                 $pagerestrictions = array();
2420
2421                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2422                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2423                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2424                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2425                 }
2426
2427                 wfProfileIn( __METHOD__ );
2428
2429                 $dbr = wfGetDB( DB_SLAVE );
2430
2431                 if ( $this->getNamespace() == NS_FILE ) {
2432                         $tables = array( 'imagelinks', 'page_restrictions' );
2433                         $where_clauses = array(
2434                                 'il_to' => $this->getDBkey(),
2435                                 'il_from=pr_page',
2436                                 'pr_cascade' => 1
2437                         );
2438                 } else {
2439                         $tables = array( 'templatelinks', 'page_restrictions' );
2440                         $where_clauses = array(
2441                                 'tl_namespace' => $this->getNamespace(),
2442                                 'tl_title' => $this->getDBkey(),
2443                                 'tl_from=pr_page',
2444                                 'pr_cascade' => 1
2445                         );
2446                 }
2447
2448                 if ( $getPages ) {
2449                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2450                                                    'pr_expiry', 'pr_type', 'pr_level' );
2451                         $where_clauses[] = 'page_id=pr_page';
2452                         $tables[] = 'page';
2453                 } else {
2454                         $cols = array( 'pr_expiry' );
2455                 }
2456
2457                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2458
2459                 $sources = $getPages ? array() : false;
2460                 $now = wfTimestampNow();
2461                 $purgeExpired = false;
2462
2463                 foreach ( $res as $row ) {
2464                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2465                         if ( $expiry > $now ) {
2466                                 if ( $getPages ) {
2467                                         $page_id = $row->pr_page;
2468                                         $page_ns = $row->page_namespace;
2469                                         $page_title = $row->page_title;
2470                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2471                                         # Add groups needed for each restriction type if its not already there
2472                                         # Make sure this restriction type still exists
2473
2474                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2475                                                 $pagerestrictions[$row->pr_type] = array();
2476                                         }
2477
2478                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2479                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2480                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2481                                         }
2482                                 } else {
2483                                         $sources = true;
2484                                 }
2485                         } else {
2486                                 // Trigger lazy purge of expired restrictions from the db
2487                                 $purgeExpired = true;
2488                         }
2489                 }
2490                 if ( $purgeExpired ) {
2491                         Title::purgeExpiredRestrictions();
2492                 }
2493
2494                 if ( $getPages ) {
2495                         $this->mCascadeSources = $sources;
2496                         $this->mCascadingRestrictions = $pagerestrictions;
2497                 } else {
2498                         $this->mHasCascadingRestrictions = $sources;
2499                 }
2500
2501                 wfProfileOut( __METHOD__ );
2502                 return array( $sources, $pagerestrictions );
2503         }
2504
2505         /**
2506          * Accessor/initialisation for mRestrictions
2507          *
2508          * @param $action String action that permission needs to be checked for
2509          * @return Array of Strings the array of groups allowed to edit this article
2510          */
2511         public function getRestrictions( $action ) {
2512                 if ( !$this->mRestrictionsLoaded ) {
2513                         $this->loadRestrictions();
2514                 }
2515                 return isset( $this->mRestrictions[$action] )
2516                                 ? $this->mRestrictions[$action]
2517                                 : array();
2518         }
2519
2520         /**
2521          * Get the expiry time for the restriction against a given action
2522          *
2523          * @param $action
2524          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2525          *     or not protected at all, or false if the action is not recognised.
2526          */
2527         public function getRestrictionExpiry( $action ) {
2528                 if ( !$this->mRestrictionsLoaded ) {
2529                         $this->loadRestrictions();
2530                 }
2531                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2532         }
2533
2534         /**
2535          * Returns cascading restrictions for the current article
2536          *
2537          * @return Boolean
2538          */
2539         function areRestrictionsCascading() {
2540                 if ( !$this->mRestrictionsLoaded ) {
2541                         $this->loadRestrictions();
2542                 }
2543
2544                 return $this->mCascadeRestriction;
2545         }
2546
2547         /**
2548          * Loads a string into mRestrictions array
2549          *
2550          * @param $res Resource restrictions as an SQL result.
2551          * @param $oldFashionedRestrictions String comma-separated list of page
2552          *        restrictions from page table (pre 1.10)
2553          */
2554         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2555                 $rows = array();
2556
2557                 foreach ( $res as $row ) {
2558                         $rows[] = $row;
2559                 }
2560
2561                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2562         }
2563
2564         /**
2565          * Compiles list of active page restrictions from both page table (pre 1.10)
2566          * and page_restrictions table for this existing page.
2567          * Public for usage by LiquidThreads.
2568          *
2569          * @param $rows array of db result objects
2570          * @param $oldFashionedRestrictions string comma-separated list of page
2571          *        restrictions from page table (pre 1.10)
2572          */
2573         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2574                 global $wgContLang;
2575                 $dbr = wfGetDB( DB_SLAVE );
2576
2577                 $restrictionTypes = $this->getRestrictionTypes();
2578
2579                 foreach ( $restrictionTypes as $type ) {
2580                         $this->mRestrictions[$type] = array();
2581                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2582                 }
2583
2584                 $this->mCascadeRestriction = false;
2585
2586                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2587
2588                 if ( $oldFashionedRestrictions === null ) {
2589                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2590                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2591                 }
2592
2593                 if ( $oldFashionedRestrictions != '' ) {
2594
2595                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2596                                 $temp = explode( '=', trim( $restrict ) );
2597                                 if ( count( $temp ) == 1 ) {
2598                                         // old old format should be treated as edit/move restriction
2599                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2600                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2601                                 } else {
2602                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2603                                 }
2604                         }
2605
2606                         $this->mOldRestrictions = true;
2607
2608                 }
2609
2610                 if ( count( $rows ) ) {
2611                         # Current system - load second to make them override.
2612                         $now = wfTimestampNow();
2613                         $purgeExpired = false;
2614
2615                         # Cycle through all the restrictions.
2616                         foreach ( $rows as $row ) {
2617
2618                                 // Don't take care of restrictions types that aren't allowed
2619                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2620                                         continue;
2621
2622                                 // This code should be refactored, now that it's being used more generally,
2623                                 // But I don't really see any harm in leaving it in Block for now -werdna
2624                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2625
2626                                 // Only apply the restrictions if they haven't expired!
2627                                 if ( !$expiry || $expiry > $now ) {
2628                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2629                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2630
2631                                         $this->mCascadeRestriction |= $row->pr_cascade;
2632                                 } else {
2633                                         // Trigger a lazy purge of expired restrictions
2634                                         $purgeExpired = true;
2635                                 }
2636                         }
2637
2638                         if ( $purgeExpired ) {
2639                                 Title::purgeExpiredRestrictions();
2640                         }
2641                 }
2642
2643                 $this->mRestrictionsLoaded = true;
2644         }
2645
2646         /**
2647          * Load restrictions from the page_restrictions table
2648          *
2649          * @param $oldFashionedRestrictions String comma-separated list of page
2650          *        restrictions from page table (pre 1.10)
2651          */
2652         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2653                 global $wgContLang;
2654                 if ( !$this->mRestrictionsLoaded ) {
2655                         if ( $this->exists() ) {
2656                                 $dbr = wfGetDB( DB_SLAVE );
2657
2658                                 $res = $dbr->select(
2659                                         'page_restrictions',
2660                                         '*',
2661                                         array( 'pr_page' => $this->getArticleID() ),
2662                                         __METHOD__
2663                                 );
2664
2665                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2666                         } else {
2667                                 $title_protection = $this->getTitleProtection();
2668
2669                                 if ( $title_protection ) {
2670                                         $now = wfTimestampNow();
2671                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2672
2673                                         if ( !$expiry || $expiry > $now ) {
2674                                                 // Apply the restrictions
2675                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2676                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2677                                         } else { // Get rid of the old restrictions
2678                                                 Title::purgeExpiredRestrictions();
2679                                                 $this->mTitleProtection = false;
2680                                         }
2681                                 } else {
2682                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2683                                 }
2684                                 $this->mRestrictionsLoaded = true;
2685                         }
2686                 }
2687         }
2688
2689         /**
2690          * Flush the protection cache in this object and force reload from the database.
2691          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2692          */
2693         public function flushRestrictions() {
2694                 $this->mRestrictionsLoaded = false;
2695                 $this->mTitleProtection = null;
2696         }
2697
2698         /**
2699          * Purge expired restrictions from the page_restrictions table
2700          */
2701         static function purgeExpiredRestrictions() {
2702                 $dbw = wfGetDB( DB_MASTER );
2703                 $dbw->delete(
2704                         'page_restrictions',
2705                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2706                         __METHOD__
2707                 );
2708
2709                 $dbw->delete(
2710                         'protected_titles',
2711                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2712                         __METHOD__
2713                 );
2714         }
2715
2716         /**
2717          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2718          *
2719          * @return Bool
2720          */
2721         public function hasSubpages() {
2722                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2723                         # Duh
2724                         return false;
2725                 }
2726
2727                 # We dynamically add a member variable for the purpose of this method
2728                 # alone to cache the result.  There's no point in having it hanging
2729                 # around uninitialized in every Title object; therefore we only add it
2730                 # if needed and don't declare it statically.
2731                 if ( isset( $this->mHasSubpages ) ) {
2732                         return $this->mHasSubpages;
2733                 }
2734
2735                 $subpages = $this->getSubpages( 1 );
2736                 if ( $subpages instanceof TitleArray ) {
2737                         return $this->mHasSubpages = (bool)$subpages->count();
2738                 }
2739                 return $this->mHasSubpages = false;
2740         }
2741
2742         /**
2743          * Get all subpages of this page.
2744          *
2745          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
2746          * @return mixed TitleArray, or empty array if this page's namespace
2747          *  doesn't allow subpages
2748          */
2749         public function getSubpages( $limit = -1 ) {
2750                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2751                         return array();
2752                 }
2753
2754                 $dbr = wfGetDB( DB_SLAVE );
2755                 $conds['page_namespace'] = $this->getNamespace();
2756                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2757                 $options = array();
2758                 if ( $limit > -1 ) {
2759                         $options['LIMIT'] = $limit;
2760                 }
2761                 return $this->mSubpages = TitleArray::newFromResult(
2762                         $dbr->select( 'page',
2763                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2764                                 $conds,
2765                                 __METHOD__,
2766                                 $options
2767                         )
2768                 );
2769         }
2770
2771         /**
2772          * Is there a version of this page in the deletion archive?
2773          *
2774          * @return Int the number of archived revisions
2775          */
2776         public function isDeleted() {
2777                 if ( $this->getNamespace() < 0 ) {
2778                         $n = 0;
2779                 } else {
2780                         $dbr = wfGetDB( DB_SLAVE );
2781
2782                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2783                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2784                                 __METHOD__
2785                         );
2786                         if ( $this->getNamespace() == NS_FILE ) {
2787                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2788                                         array( 'fa_name' => $this->getDBkey() ),
2789                                         __METHOD__
2790                                 );
2791                         }
2792                 }
2793                 return (int)$n;
2794         }
2795
2796         /**
2797          * Is there a version of this page in the deletion archive?
2798          *
2799          * @return Boolean
2800          */
2801         public function isDeletedQuick() {
2802                 if ( $this->getNamespace() < 0 ) {
2803                         return false;
2804                 }
2805                 $dbr = wfGetDB( DB_SLAVE );
2806                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2807                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2808                         __METHOD__
2809                 );
2810                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2811                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2812                                 array( 'fa_name' => $this->getDBkey() ),
2813                                 __METHOD__
2814                         );
2815                 }
2816                 return $deleted;
2817         }
2818
2819         /**
2820          * Get the article ID for this Title from the link cache,
2821          * adding it if necessary
2822          *
2823          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2824          *  for update
2825          * @return Int the ID
2826          */
2827         public function getArticleID( $flags = 0 ) {
2828                 if ( $this->getNamespace() < 0 ) {
2829                         return $this->mArticleID = 0;
2830                 }
2831                 $linkCache = LinkCache::singleton();
2832                 if ( $flags & self::GAID_FOR_UPDATE ) {
2833                         $oldUpdate = $linkCache->forUpdate( true );
2834                         $linkCache->clearLink( $this );
2835                         $this->mArticleID = $linkCache->addLinkObj( $this );
2836                         $linkCache->forUpdate( $oldUpdate );
2837                 } else {
2838                         if ( -1 == $this->mArticleID ) {
2839                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2840                         }
2841                 }
2842                 return $this->mArticleID;
2843         }
2844
2845         /**
2846          * Is this an article that is a redirect page?
2847          * Uses link cache, adding it if necessary
2848          *
2849          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2850          * @return Bool
2851          */
2852         public function isRedirect( $flags = 0 ) {
2853                 if ( !is_null( $this->mRedirect ) ) {
2854                         return $this->mRedirect;
2855                 }
2856                 # Calling getArticleID() loads the field from cache as needed
2857                 if ( !$this->getArticleID( $flags ) ) {
2858                         return $this->mRedirect = false;
2859                 }
2860                 $linkCache = LinkCache::singleton();
2861                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2862
2863                 return $this->mRedirect;
2864         }
2865
2866         /**
2867          * What is the length of this page?
2868          * Uses link cache, adding it if necessary
2869          *
2870          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2871          * @return Int
2872          */
2873         public function getLength( $flags = 0 ) {
2874                 if ( $this->mLength != -1 ) {
2875                         return $this->mLength;
2876                 }
2877                 # Calling getArticleID() loads the field from cache as needed
2878                 if ( !$this->getArticleID( $flags ) ) {
2879                         return $this->mLength = 0;
2880                 }
2881                 $linkCache = LinkCache::singleton();
2882                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2883
2884                 return $this->mLength;
2885         }
2886
2887         /**
2888          * What is the page_latest field for this page?
2889          *
2890          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2891          * @return Int or 0 if the page doesn't exist
2892          */
2893         public function getLatestRevID( $flags = 0 ) {
2894                 if ( $this->mLatestID !== false ) {
2895                         return intval( $this->mLatestID );
2896                 }
2897                 # Calling getArticleID() loads the field from cache as needed
2898                 if ( !$this->getArticleID( $flags ) ) {
2899                         return $this->mLatestID = 0;
2900                 }
2901                 $linkCache = LinkCache::singleton();
2902                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2903
2904                 return $this->mLatestID;
2905         }
2906
2907         /**
2908          * This clears some fields in this object, and clears any associated
2909          * keys in the "bad links" section of the link cache.
2910          *
2911          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
2912          * loading of the new page_id. It's also called from
2913          * WikiPage::doDeleteArticle()
2914          *
2915          * @param $newid Int the new Article ID
2916          */
2917         public function resetArticleID( $newid ) {
2918                 $linkCache = LinkCache::singleton();
2919                 $linkCache->clearLink( $this );
2920
2921                 if ( $newid === false ) {
2922                         $this->mArticleID = -1;
2923                 } else {
2924                         $this->mArticleID = intval( $newid );
2925                 }
2926                 $this->mRestrictionsLoaded = false;
2927                 $this->mRestrictions = array();
2928                 $this->mRedirect = null;
2929                 $this->mLength = -1;
2930                 $this->mLatestID = false;
2931                 $this->mEstimateRevisions = null;
2932         }
2933
2934         /**
2935          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2936          *
2937          * @param $text String containing title to capitalize
2938          * @param $ns int namespace index, defaults to NS_MAIN
2939          * @return String containing capitalized title
2940          */
2941         public static function capitalize( $text, $ns = NS_MAIN ) {
2942                 global $wgContLang;
2943
2944                 if ( MWNamespace::isCapitalized( $ns ) ) {
2945                         return $wgContLang->ucfirst( $text );
2946                 } else {
2947                         return $text;
2948                 }
2949         }
2950
2951         /**
2952          * Secure and split - main initialisation function for this object
2953          *
2954          * Assumes that mDbkeyform has been set, and is urldecoded
2955          * and uses underscores, but not otherwise munged.  This function
2956          * removes illegal characters, splits off the interwiki and
2957          * namespace prefixes, sets the other forms, and canonicalizes
2958          * everything.
2959          *
2960          * @return Bool true on success
2961          */
2962         private function secureAndSplit() {
2963                 global $wgContLang, $wgLocalInterwiki;
2964
2965                 # Initialisation
2966                 $this->mInterwiki = $this->mFragment = '';
2967                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2968
2969                 $dbkey = $this->mDbkeyform;
2970
2971                 # Strip Unicode bidi override characters.
2972                 # Sometimes they slip into cut-n-pasted page titles, where the
2973                 # override chars get included in list displays.
2974                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2975
2976                 # Clean up whitespace
2977                 # Note: use of the /u option on preg_replace here will cause
2978                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2979                 # conveniently disabling them.
2980                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2981                 $dbkey = trim( $dbkey, '_' );
2982
2983                 if ( $dbkey == '' ) {
2984                         return false;
2985                 }
2986
2987                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2988                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2989                         return false;
2990                 }
2991
2992                 $this->mDbkeyform = $dbkey;
2993
2994                 # Initial colon indicates main namespace rather than specified default
2995                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2996                 if ( ':' == $dbkey[0] ) {
2997                         $this->mNamespace = NS_MAIN;
2998                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2999                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
3000                 }
3001
3002                 # Namespace or interwiki prefix
3003                 $firstPass = true;
3004                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
3005                 do {
3006                         $m = array();
3007                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3008                                 $p = $m[1];
3009                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3010                                         # Ordinary namespace
3011                                         $dbkey = $m[2];
3012                                         $this->mNamespace = $ns;
3013                                         # For Talk:X pages, check if X has a "namespace" prefix
3014                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3015                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3016                                                         # Disallow Talk:File:x type titles...
3017                                                         return false;
3018                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3019                                                         # Disallow Talk:Interwiki:x type titles...
3020                                                         return false;
3021                                                 }
3022                                         }
3023                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3024                                         if ( !$firstPass ) {
3025                                                 # Can't make a local interwiki link to an interwiki link.
3026                                                 # That's just crazy!
3027                                                 return false;
3028                                         }
3029
3030                                         # Interwiki link
3031                                         $dbkey = $m[2];
3032                                         $this->mInterwiki = $wgContLang->lc( $p );
3033
3034                                         # Redundant interwiki prefix to the local wiki
3035                                         if ( $wgLocalInterwiki !== false
3036                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3037                                         {
3038                                                 if ( $dbkey == '' ) {
3039                                                         # Can't have an empty self-link
3040                                                         return false;
3041                                                 }
3042                                                 $this->mInterwiki = '';
3043                                                 $firstPass = false;
3044                                                 # Do another namespace split...
3045                                                 continue;
3046                                         }
3047
3048                                         # If there's an initial colon after the interwiki, that also
3049                                         # resets the default namespace
3050                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3051                                                 $this->mNamespace = NS_MAIN;
3052                                                 $dbkey = substr( $dbkey, 1 );
3053                                         }
3054                                 }
3055                                 # If there's no recognized interwiki or namespace,
3056                                 # then let the colon expression be part of the title.
3057                         }
3058                         break;
3059                 } while ( true );
3060
3061                 # We already know that some pages won't be in the database!
3062                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3063                         $this->mArticleID = 0;
3064                 }
3065                 $fragment = strstr( $dbkey, '#' );
3066                 if ( false !== $fragment ) {
3067                         $this->setFragment( $fragment );
3068                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3069                         # remove whitespace again: prevents "Foo_bar_#"
3070                         # becoming "Foo_bar_"
3071                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3072                 }
3073
3074                 # Reject illegal characters.
3075                 $rxTc = self::getTitleInvalidRegex();
3076                 if ( preg_match( $rxTc, $dbkey ) ) {
3077                         return false;
3078                 }
3079
3080                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3081                 # reachable due to the way web browsers deal with 'relative' URLs.
3082                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3083                 if ( strpos( $dbkey, '.' ) !== false &&
3084                          ( $dbkey === '.' || $dbkey === '..' ||
3085                            strpos( $dbkey, './' ) === 0  ||
3086                            strpos( $dbkey, '../' ) === 0 ||
3087                            strpos( $dbkey, '/./' ) !== false ||
3088                            strpos( $dbkey, '/../' ) !== false  ||
3089                            substr( $dbkey, -2 ) == '/.' ||
3090                            substr( $dbkey, -3 ) == '/..' ) )
3091                 {
3092                         return false;
3093                 }
3094
3095                 # Magic tilde sequences? Nu-uh!
3096                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3097                         return false;
3098                 }
3099
3100                 # Limit the size of titles to 255 bytes. This is typically the size of the
3101                 # underlying database field. We make an exception for special pages, which
3102                 # don't need to be stored in the database, and may edge over 255 bytes due
3103                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3104                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
3105                   strlen( $dbkey ) > 512 )
3106                 {
3107                         return false;
3108                 }
3109
3110                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3111                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3112                 # other site might be case-sensitive.
3113                 $this->mUserCaseDBKey = $dbkey;
3114                 if ( $this->mInterwiki == '' ) {
3115                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3116                 }
3117
3118                 # Can't make a link to a namespace alone... "empty" local links can only be
3119                 # self-links with a fragment identifier.
3120                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3121                         return false;
3122                 }
3123
3124                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3125                 // IP names are not allowed for accounts, and can only be referring to
3126                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3127                 // there are numerous ways to present the same IP. Having sp:contribs scan
3128                 // them all is silly and having some show the edits and others not is
3129                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3130                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3131                         ? IP::sanitizeIP( $dbkey )
3132                         : $dbkey;
3133
3134                 // Any remaining initial :s are illegal.
3135                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3136                         return false;
3137                 }
3138
3139                 # Fill fields
3140                 $this->mDbkeyform = $dbkey;
3141                 $this->mUrlform = wfUrlencode( $dbkey );
3142
3143                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3144
3145                 return true;
3146         }
3147
3148         /**
3149          * Get an array of Title objects linking to this Title
3150          * Also stores the IDs in the link cache.
3151          *
3152          * WARNING: do not use this function on arbitrary user-supplied titles!
3153          * On heavily-used templates it will max out the memory.
3154          *
3155          * @param $options Array: may be FOR UPDATE
3156          * @param $table String: table name
3157          * @param $prefix String: fields prefix
3158          * @return Array of Title objects linking here
3159          */
3160         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3161                 if ( count( $options ) > 0 ) {
3162                         $db = wfGetDB( DB_MASTER );
3163                 } else {
3164                         $db = wfGetDB( DB_SLAVE );
3165                 }
3166
3167                 $res = $db->select(
3168                         array( 'page', $table ),
3169                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3170                         array(
3171                                 "{$prefix}_from=page_id",
3172                                 "{$prefix}_namespace" => $this->getNamespace(),
3173                                 "{$prefix}_title"     => $this->getDBkey() ),
3174                         __METHOD__,
3175                         $options
3176                 );
3177
3178                 $retVal = array();
3179                 if ( $res->numRows() ) {
3180                         $linkCache = LinkCache::singleton();
3181                         foreach ( $res as $row ) {
3182                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3183                                 if ( $titleObj ) {
3184                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3185                                         $retVal[] = $titleObj;
3186                                 }
3187                         }
3188                 }
3189                 return $retVal;
3190         }
3191
3192         /**
3193          * Get an array of Title objects using this Title as a template
3194          * Also stores the IDs in the link cache.
3195          *
3196          * WARNING: do not use this function on arbitrary user-supplied titles!
3197          * On heavily-used templates it will max out the memory.
3198          *
3199          * @param $options Array: may be FOR UPDATE
3200          * @return Array of Title the Title objects linking here
3201          */
3202         public function getTemplateLinksTo( $options = array() ) {
3203                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3204         }
3205
3206         /**
3207          * Get an array of Title objects linked from this Title
3208          * Also stores the IDs in the link cache.
3209          *
3210          * WARNING: do not use this function on arbitrary user-supplied titles!
3211          * On heavily-used templates it will max out the memory.
3212          *
3213          * @param $options Array: may be FOR UPDATE
3214          * @param $table String: table name
3215          * @param $prefix String: fields prefix
3216          * @return Array of Title objects linking here
3217          */
3218         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3219                 $id = $this->getArticleID();
3220
3221                 # If the page doesn't exist; there can't be any link from this page
3222                 if ( !$id ) {
3223                         return array();
3224                 }
3225
3226                 if ( count( $options ) > 0 ) {
3227                         $db = wfGetDB( DB_MASTER );
3228                 } else {
3229                         $db = wfGetDB( DB_SLAVE );
3230                 }
3231
3232                 $namespaceFiled = "{$prefix}_namespace";
3233                 $titleField = "{$prefix}_title";
3234
3235                 $res = $db->select(
3236                         array( $table, 'page' ),
3237                         array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
3238                         array( "{$prefix}_from" => $id ),
3239                         __METHOD__,
3240                         $options,
3241                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3242                 );
3243
3244                 $retVal = array();
3245                 if ( $res->numRows() ) {
3246                         $linkCache = LinkCache::singleton();
3247                         foreach ( $res as $row ) {
3248                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3249                                 if ( $titleObj ) {
3250                                         if ( $row->page_id ) {
3251                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3252                                         } else {
3253                                                 $linkCache->addBadLinkObj( $titleObj );
3254                                         }
3255                                         $retVal[] = $titleObj;
3256                                 }
3257                         }
3258                 }
3259                 return $retVal;
3260         }
3261
3262         /**
3263          * Get an array of Title objects used on this Title as a template
3264          * Also stores the IDs in the link cache.
3265          *
3266          * WARNING: do not use this function on arbitrary user-supplied titles!
3267          * On heavily-used templates it will max out the memory.
3268          *
3269          * @param $options Array: may be FOR UPDATE
3270          * @return Array of Title the Title objects used here
3271          */
3272         public function getTemplateLinksFrom( $options = array() ) {
3273                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3274         }
3275
3276         /**
3277          * Get an array of Title objects referring to non-existent articles linked from this page
3278          *
3279          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3280          * @return Array of Title the Title objects
3281          */
3282         public function getBrokenLinksFrom() {
3283                 if ( $this->getArticleID() == 0 ) {
3284                         # All links from article ID 0 are false positives
3285                         return array();
3286                 }
3287
3288                 $dbr = wfGetDB( DB_SLAVE );
3289                 $res = $dbr->select(
3290                         array( 'page', 'pagelinks' ),
3291                         array( 'pl_namespace', 'pl_title' ),
3292                         array(
3293                                 'pl_from' => $this->getArticleID(),
3294                                 'page_namespace IS NULL'
3295                         ),
3296                         __METHOD__, array(),
3297                         array(
3298                                 'page' => array(
3299                                         'LEFT JOIN',
3300                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3301                                 )
3302                         )
3303                 );
3304
3305                 $retVal = array();
3306                 foreach ( $res as $row ) {
3307                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3308                 }
3309                 return $retVal;
3310         }
3311
3312
3313         /**
3314          * Get a list of URLs to purge from the Squid cache when this
3315          * page changes
3316          *
3317          * @return Array of String the URLs
3318          */
3319         public function getSquidURLs() {
3320                 global $wgContLang;
3321
3322                 $urls = array(
3323                         $this->getInternalURL(),
3324                         $this->getInternalURL( 'action=history' )
3325                 );
3326
3327                 // purge variant urls as well
3328                 if ( $wgContLang->hasVariants() ) {
3329                         $variants = $wgContLang->getVariants();
3330                         foreach ( $variants as $vCode ) {
3331                                 $urls[] = $this->getInternalURL( '', $vCode );
3332                         }
3333                 }
3334
3335                 return $urls;
3336         }
3337
3338         /**
3339          * Purge all applicable Squid URLs
3340          */
3341         public function purgeSquid() {
3342                 global $wgUseSquid;
3343                 if ( $wgUseSquid ) {
3344                         $urls = $this->getSquidURLs();
3345                         $u = new SquidUpdate( $urls );
3346                         $u->doUpdate();
3347                 }
3348         }
3349
3350         /**
3351          * Move this page without authentication
3352          *
3353          * @param $nt Title the new page Title
3354          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3355          */
3356         public function moveNoAuth( &$nt ) {
3357                 return $this->moveTo( $nt, false );
3358         }
3359
3360         /**
3361          * Check whether a given move operation would be valid.
3362          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3363          *
3364          * @param $nt Title the new title
3365          * @param $auth Bool indicates whether $wgUser's permissions
3366          *  should be checked
3367          * @param $reason String is the log summary of the move, used for spam checking
3368          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3369          */
3370         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3371                 global $wgUser;
3372
3373                 $errors = array();
3374                 if ( !$nt ) {
3375                         // Normally we'd add this to $errors, but we'll get
3376                         // lots of syntax errors if $nt is not an object
3377                         return array( array( 'badtitletext' ) );
3378                 }
3379                 if ( $this->equals( $nt ) ) {
3380                         $errors[] = array( 'selfmove' );
3381                 }
3382                 if ( !$this->isMovable() ) {
3383                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3384                 }
3385                 if ( $nt->getInterwiki() != '' ) {
3386                         $errors[] = array( 'immobile-target-namespace-iw' );
3387                 }
3388                 if ( !$nt->isMovable() ) {
3389                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3390                 }
3391
3392                 $oldid = $this->getArticleID();
3393                 $newid = $nt->getArticleID();
3394
3395                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3396                         $errors[] = array( 'articleexists' );
3397                 }
3398                 if ( ( $this->getDBkey() == '' ) ||
3399                          ( !$oldid ) ||
3400                          ( $nt->getDBkey() == '' ) ) {
3401                         $errors[] = array( 'badarticleerror' );
3402                 }
3403
3404                 // Image-specific checks
3405                 if ( $this->getNamespace() == NS_FILE ) {
3406                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3407                 }
3408
3409                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3410                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3411                 }
3412
3413                 if ( $auth ) {
3414                         $errors = wfMergeErrorArrays( $errors,
3415                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3416                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3417                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3418                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3419                 }
3420
3421                 $match = EditPage::matchSummarySpamRegex( $reason );
3422                 if ( $match !== false ) {
3423                         // This is kind of lame, won't display nice
3424                         $errors[] = array( 'spamprotectiontext' );
3425                 }
3426
3427                 $err = null;
3428                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3429                         $errors[] = array( 'hookaborted', $err );
3430                 }
3431
3432                 # The move is allowed only if (1) the target doesn't exist, or
3433                 # (2) the target is a redirect to the source, and has no history
3434                 # (so we can undo bad moves right after they're done).
3435
3436                 if ( 0 != $newid ) { # Target exists; check for validity
3437                         if ( !$this->isValidMoveTarget( $nt ) ) {
3438                                 $errors[] = array( 'articleexists' );
3439                         }
3440                 } else {
3441                         $tp = $nt->getTitleProtection();
3442                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3443                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3444                                 $errors[] = array( 'cantmove-titleprotected' );
3445                         }
3446                 }
3447                 if ( empty( $errors ) ) {
3448                         return true;
3449                 }
3450                 return $errors;
3451         }
3452
3453         /**
3454          * Check if the requested move target is a valid file move target
3455          * @param Title $nt Target title
3456          * @return array List of errors
3457          */
3458         protected function validateFileMoveOperation( $nt ) {
3459                 global $wgUser;
3460
3461                 $errors = array();
3462
3463                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3464
3465                 $file = wfLocalFile( $this );
3466                 if ( $file->exists() ) {
3467                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3468                                 $errors[] = array( 'imageinvalidfilename' );
3469                         }
3470                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3471                                 $errors[] = array( 'imagetypemismatch' );
3472                         }
3473                 }
3474
3475                 if ( $nt->getNamespace() != NS_FILE ) {
3476                         $errors[] = array( 'imagenocrossnamespace' );
3477                         // From here we want to do checks on a file object, so if we can't
3478                         // create one, we must return.
3479                         return $errors;
3480                 }
3481
3482                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3483
3484                 $destFile = wfLocalFile( $nt );
3485                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3486                         $errors[] = array( 'file-exists-sharedrepo' );
3487                 }
3488
3489                 return $errors;
3490         }
3491
3492         /**
3493          * Move a title to a new location
3494          *
3495          * @param $nt Title the new title
3496          * @param $auth Bool indicates whether $wgUser's permissions
3497          *  should be checked
3498          * @param $reason String the reason for the move
3499          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3500          *  Ignored if the user doesn't have the suppressredirect right.
3501          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3502          */
3503         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3504                 global $wgUser;
3505                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3506                 if ( is_array( $err ) ) {
3507                         // Auto-block user's IP if the account was "hard" blocked
3508                         $wgUser->spreadAnyEditBlock();
3509                         return $err;
3510                 }
3511
3512                 // If it is a file, move it first.
3513                 // It is done before all other moving stuff is done because it's hard to revert.
3514                 $dbw = wfGetDB( DB_MASTER );
3515                 if ( $this->getNamespace() == NS_FILE ) {
3516                         $file = wfLocalFile( $this );
3517                         if ( $file->exists() ) {
3518                                 $status = $file->move( $nt );
3519                                 if ( !$status->isOk() ) {
3520                                         return $status->getErrorsArray();
3521                                 }
3522                         }
3523                         // Clear RepoGroup process cache
3524                         RepoGroup::singleton()->clearCache( $this );
3525                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3526                 }
3527
3528                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3529                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3530                 $protected = $this->isProtected();
3531
3532                 // Do the actual move
3533                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3534                 if ( is_array( $err ) ) {
3535                         # @todo FIXME: What about the File we have already moved?
3536                         $dbw->rollback( __METHOD__ );
3537                         return $err;
3538                 }
3539
3540                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3541                 // cl_timestamp, which may disturb time-based lists on some sites.
3542                 $prefixes = $dbw->select(
3543                         'categorylinks',
3544                         array( 'cl_sortkey_prefix', 'cl_to' ),
3545                         array( 'cl_from' => $pageid ),
3546                         __METHOD__
3547                 );
3548                 foreach ( $prefixes as $prefixRow ) {
3549                         $prefix = $prefixRow->cl_sortkey_prefix;
3550                         $catTo = $prefixRow->cl_to;
3551                         $dbw->update( 'categorylinks',
3552                                 array(
3553                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3554                                                 $nt->getCategorySortkey( $prefix ) ),
3555                                         'cl_timestamp=cl_timestamp' ),
3556                                 array(
3557                                         'cl_from' => $pageid,
3558                                         'cl_to' => $catTo ),
3559                                 __METHOD__
3560                         );
3561                 }
3562
3563                 $redirid = $this->getArticleID();
3564
3565                 if ( $protected ) {
3566                         # Protect the redirect title as the title used to be...
3567                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3568                                 array(
3569                                         'pr_page'    => $redirid,
3570                                         'pr_type'    => 'pr_type',
3571                                         'pr_level'   => 'pr_level',
3572                                         'pr_cascade' => 'pr_cascade',
3573                                         'pr_user'    => 'pr_user',
3574                                         'pr_expiry'  => 'pr_expiry'
3575                                 ),
3576                                 array( 'pr_page' => $pageid ),
3577                                 __METHOD__,
3578                                 array( 'IGNORE' )
3579                         );
3580                         # Update the protection log
3581                         $log = new LogPage( 'protect' );
3582                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3583                         if ( $reason ) {
3584                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3585                         }
3586                         // @todo FIXME: $params?
3587                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3588                 }
3589
3590                 # Update watchlists
3591                 $oldnamespace = $this->getNamespace() & ~1;
3592                 $newnamespace = $nt->getNamespace() & ~1;
3593                 $oldtitle = $this->getDBkey();
3594                 $newtitle = $nt->getDBkey();
3595
3596                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3597                         WatchedItem::duplicateEntries( $this, $nt );
3598                 }
3599
3600                 $dbw->commit( __METHOD__ );
3601
3602                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3603                 return true;
3604         }
3605
3606         /**
3607          * Move page to a title which is either a redirect to the
3608          * source page or nonexistent
3609          *
3610          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3611          * @param $reason String The reason for the move
3612          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3613          *   if the user doesn't have the suppressredirect right
3614          */
3615         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3616                 global $wgUser, $wgContLang;
3617
3618                 if ( $nt->exists() ) {
3619                         $moveOverRedirect = true;
3620                         $logType = 'move_redir';
3621                 } else {
3622                         $moveOverRedirect = false;
3623                         $logType = 'move';
3624                 }
3625
3626                 $redirectSuppressed = !$createRedirect && $wgUser->isAllowed( 'suppressredirect' );
3627
3628                 $logEntry = new ManualLogEntry( 'move', $logType );
3629                 $logEntry->setPerformer( $wgUser );
3630                 $logEntry->setTarget( $this );
3631                 $logEntry->setComment( $reason );
3632                 $logEntry->setParameters( array(
3633                         '4::target' => $nt->getPrefixedText(),
3634                         '5::noredir' => $redirectSuppressed ? '1': '0',
3635                 ) );
3636
3637                 $formatter = LogFormatter::newFromEntry( $logEntry );
3638                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3639                 $comment = $formatter->getPlainActionText();
3640                 if ( $reason ) {
3641                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3642                 }
3643                 # Truncate for whole multibyte characters.
3644                 $comment = $wgContLang->truncate( $comment, 255 );
3645
3646                 $oldid = $this->getArticleID();
3647
3648                 $dbw = wfGetDB( DB_MASTER );
3649
3650                 $newpage = WikiPage::factory( $nt );
3651
3652                 if ( $moveOverRedirect ) {
3653                         $newid = $nt->getArticleID();
3654
3655                         # Delete the old redirect. We don't save it to history since
3656                         # by definition if we've got here it's rather uninteresting.
3657                         # We have to remove it so that the next step doesn't trigger
3658                         # a conflict on the unique namespace+title index...
3659                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3660
3661                         $newpage->doDeleteUpdates( $newid );
3662                 }
3663
3664                 # Save a null revision in the page's history notifying of the move
3665                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3666                 if ( !is_object( $nullRevision ) ) {
3667                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3668                 }
3669                 $nullRevId = $nullRevision->insertOn( $dbw );
3670
3671                 # Change the name of the target page:
3672                 $dbw->update( 'page',
3673                         /* SET */ array(
3674                                 'page_namespace' => $nt->getNamespace(),
3675                                 'page_title'     => $nt->getDBkey(),
3676                         ),
3677                         /* WHERE */ array( 'page_id' => $oldid ),
3678                         __METHOD__
3679                 );
3680
3681                 $this->resetArticleID( 0 );
3682                 $nt->resetArticleID( $oldid );
3683
3684                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3685
3686                 wfRunHooks( 'NewRevisionFromEditComplete',
3687                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3688
3689                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3690
3691                 if ( !$moveOverRedirect ) {
3692                         WikiPage::onArticleCreate( $nt );
3693                 }
3694
3695                 # Recreate the redirect, this time in the other direction.
3696                 if ( $redirectSuppressed ) {
3697                         WikiPage::onArticleDelete( $this );
3698                 } else {
3699                         $mwRedir = MagicWord::get( 'redirect' );
3700                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3701                         $redirectArticle = WikiPage::factory( $this );
3702                         $newid = $redirectArticle->insertOn( $dbw );
3703                         if ( $newid ) { // sanity
3704                                 $redirectRevision = new Revision( array(
3705                                         'page'    => $newid,
3706                                         'comment' => $comment,
3707                                         'text'    => $redirectText ) );
3708                                 $redirectRevision->insertOn( $dbw );
3709                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3710
3711                                 wfRunHooks( 'NewRevisionFromEditComplete',
3712                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3713
3714                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3715                         }
3716                 }
3717
3718                 # Log the move
3719                 $logid = $logEntry->insert();
3720                 $logEntry->publish( $logid );
3721         }
3722
3723         /**
3724          * Move this page's subpages to be subpages of $nt
3725          *
3726          * @param $nt Title Move target
3727          * @param $auth bool Whether $wgUser's permissions should be checked
3728          * @param $reason string The reason for the move
3729          * @param $createRedirect bool Whether to create redirects from the old subpages to
3730          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3731          * @return mixed array with old page titles as keys, and strings (new page titles) or
3732          *     arrays (errors) as values, or an error array with numeric indices if no pages
3733          *     were moved
3734          */
3735         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3736                 global $wgMaximumMovedPages;
3737                 // Check permissions
3738                 if ( !$this->userCan( 'move-subpages' ) ) {
3739                         return array( 'cant-move-subpages' );
3740                 }
3741                 // Do the source and target namespaces support subpages?
3742                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3743                         return array( 'namespace-nosubpages',
3744                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3745                 }
3746                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3747                         return array( 'namespace-nosubpages',
3748                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3749                 }
3750
3751                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3752                 $retval = array();
3753                 $count = 0;
3754                 foreach ( $subpages as $oldSubpage ) {
3755                         $count++;
3756                         if ( $count > $wgMaximumMovedPages ) {
3757                                 $retval[$oldSubpage->getPrefixedTitle()] =
3758                                                 array( 'movepage-max-pages',
3759                                                         $wgMaximumMovedPages );
3760                                 break;
3761                         }
3762
3763                         // We don't know whether this function was called before
3764                         // or after moving the root page, so check both
3765                         // $this and $nt
3766                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3767                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3768                         {
3769                                 // When moving a page to a subpage of itself,
3770                                 // don't move it twice
3771                                 continue;
3772                         }
3773                         $newPageName = preg_replace(
3774                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3775                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3776                                         $oldSubpage->getDBkey() );
3777                         if ( $oldSubpage->isTalkPage() ) {
3778                                 $newNs = $nt->getTalkPage()->getNamespace();
3779                         } else {
3780                                 $newNs = $nt->getSubjectPage()->getNamespace();
3781                         }
3782                         # Bug 14385: we need makeTitleSafe because the new page names may
3783                         # be longer than 255 characters.
3784                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3785
3786                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3787                         if ( $success === true ) {
3788                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3789                         } else {
3790                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3791                         }
3792                 }
3793                 return $retval;
3794         }
3795
3796         /**
3797          * Checks if this page is just a one-rev redirect.
3798          * Adds lock, so don't use just for light purposes.
3799          *
3800          * @return Bool
3801          */
3802         public function isSingleRevRedirect() {
3803                 $dbw = wfGetDB( DB_MASTER );
3804                 # Is it a redirect?
3805                 $row = $dbw->selectRow( 'page',
3806                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3807                         $this->pageCond(),
3808                         __METHOD__,
3809                         array( 'FOR UPDATE' )
3810                 );
3811                 # Cache some fields we may want
3812                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3813                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3814                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3815                 if ( !$this->mRedirect ) {
3816                         return false;
3817                 }
3818                 # Does the article have a history?
3819                 $row = $dbw->selectField( array( 'page', 'revision' ),
3820                         'rev_id',
3821                         array( 'page_namespace' => $this->getNamespace(),
3822                                 'page_title' => $this->getDBkey(),
3823                                 'page_id=rev_page',
3824                                 'page_latest != rev_id'
3825                         ),
3826                         __METHOD__,
3827                         array( 'FOR UPDATE' )
3828                 );
3829                 # Return true if there was no history
3830                 return ( $row === false );
3831         }
3832
3833         /**
3834          * Checks if $this can be moved to a given Title
3835          * - Selects for update, so don't call it unless you mean business
3836          *
3837          * @param $nt Title the new title to check
3838          * @return Bool
3839          */
3840         public function isValidMoveTarget( $nt ) {
3841                 # Is it an existing file?
3842                 if ( $nt->getNamespace() == NS_FILE ) {
3843                         $file = wfLocalFile( $nt );
3844                         if ( $file->exists() ) {
3845                                 wfDebug( __METHOD__ . ": file exists\n" );
3846                                 return false;
3847                         }
3848                 }
3849                 # Is it a redirect with no history?
3850                 if ( !$nt->isSingleRevRedirect() ) {
3851                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3852                         return false;
3853                 }
3854                 # Get the article text
3855                 $rev = Revision::newFromTitle( $nt );
3856                 if( !is_object( $rev ) ){
3857                         return false;
3858                 }
3859                 $text = $rev->getText();
3860                 # Does the redirect point to the source?
3861                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3862                 $m = array();
3863                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3864                         $redirTitle = Title::newFromText( $m[1] );
3865                         if ( !is_object( $redirTitle ) ||
3866                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3867                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3868                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3869                                 return false;
3870                         }
3871                 } else {
3872                         # Fail safe
3873                         wfDebug( __METHOD__ . ": failsafe\n" );
3874                         return false;
3875                 }
3876                 return true;
3877         }
3878
3879         /**
3880          * Get categories to which this Title belongs and return an array of
3881          * categories' names.
3882          *
3883          * @return Array of parents in the form:
3884          *        $parent => $currentarticle
3885          */
3886         public function getParentCategories() {
3887                 global $wgContLang;
3888
3889                 $data = array();
3890
3891                 $titleKey = $this->getArticleID();
3892
3893                 if ( $titleKey === 0 ) {
3894                         return $data;
3895                 }
3896
3897                 $dbr = wfGetDB( DB_SLAVE );
3898
3899                 $res = $dbr->select( 'categorylinks', '*',
3900                         array(
3901                                 'cl_from' => $titleKey,
3902                         ),
3903                         __METHOD__,
3904                         array()
3905                 );
3906
3907                 if ( $dbr->numRows( $res ) > 0 ) {
3908                         foreach ( $res as $row ) {
3909                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3910                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3911                         }
3912                 }
3913                 return $data;
3914         }
3915
3916         /**
3917          * Get a tree of parent categories
3918          *
3919          * @param $children Array with the children in the keys, to check for circular refs
3920          * @return Array Tree of parent categories
3921          */
3922         public function getParentCategoryTree( $children = array() ) {
3923                 $stack = array();
3924                 $parents = $this->getParentCategories();
3925
3926                 if ( $parents ) {
3927                         foreach ( $parents as $parent => $current ) {
3928                                 if ( array_key_exists( $parent, $children ) ) {
3929                                         # Circular reference
3930                                         $stack[$parent] = array();
3931                                 } else {
3932                                         $nt = Title::newFromText( $parent );
3933                                         if ( $nt ) {
3934                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3935                                         }
3936                                 }
3937                         }
3938                 }
3939
3940                 return $stack;
3941         }
3942
3943         /**
3944          * Get an associative array for selecting this title from
3945          * the "page" table
3946          *
3947          * @return Array suitable for the $where parameter of DB::select()
3948          */
3949         public function pageCond() {
3950                 if ( $this->mArticleID > 0 ) {
3951                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3952                         return array( 'page_id' => $this->mArticleID );
3953                 } else {
3954                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3955                 }
3956         }
3957
3958         /**
3959          * Get the revision ID of the previous revision
3960          *
3961          * @param $revId Int Revision ID. Get the revision that was before this one.
3962          * @param $flags Int Title::GAID_FOR_UPDATE
3963          * @return Int|Bool Old revision ID, or FALSE if none exists
3964          */
3965         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3966                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3967                 $revId = $db->selectField( 'revision', 'rev_id',
3968                         array(
3969                                 'rev_page' => $this->getArticleID( $flags ),
3970                                 'rev_id < ' . intval( $revId )
3971                         ),
3972                         __METHOD__,
3973                         array( 'ORDER BY' => 'rev_id DESC' )
3974                 );
3975
3976                 if ( $revId === false ) {
3977                         return false;
3978                 } else {
3979                         return intval( $revId );
3980                 }
3981         }
3982
3983         /**
3984          * Get the revision ID of the next revision
3985          *
3986          * @param $revId Int Revision ID. Get the revision that was after this one.
3987          * @param $flags Int Title::GAID_FOR_UPDATE
3988          * @return Int|Bool Next revision ID, or FALSE if none exists
3989          */
3990         public function getNextRevisionID( $revId, $flags = 0 ) {
3991                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3992                 $revId = $db->selectField( 'revision', 'rev_id',
3993                         array(
3994                                 'rev_page' => $this->getArticleID( $flags ),
3995                                 'rev_id > ' . intval( $revId )
3996                         ),
3997                         __METHOD__,
3998                         array( 'ORDER BY' => 'rev_id' )
3999                 );
4000
4001                 if ( $revId === false ) {
4002                         return false;
4003                 } else {
4004                         return intval( $revId );
4005                 }
4006         }
4007
4008         /**
4009          * Get the first revision of the page
4010          *
4011          * @param $flags Int Title::GAID_FOR_UPDATE
4012          * @return Revision|Null if page doesn't exist
4013          */
4014         public function getFirstRevision( $flags = 0 ) {
4015                 $pageId = $this->getArticleID( $flags );
4016                 if ( $pageId ) {
4017                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4018                         $row = $db->selectRow( 'revision', '*',
4019                                 array( 'rev_page' => $pageId ),
4020                                 __METHOD__,
4021                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4022                         );
4023                         if ( $row ) {
4024                                 return new Revision( $row );
4025                         }
4026                 }
4027                 return null;
4028         }
4029
4030         /**
4031          * Get the oldest revision timestamp of this page
4032          *
4033          * @param $flags Int Title::GAID_FOR_UPDATE
4034          * @return String: MW timestamp
4035          */
4036         public function getEarliestRevTime( $flags = 0 ) {
4037                 $rev = $this->getFirstRevision( $flags );
4038                 return $rev ? $rev->getTimestamp() : null;
4039         }
4040
4041         /**
4042          * Check if this is a new page
4043          *
4044          * @return bool
4045          */
4046         public function isNewPage() {
4047                 $dbr = wfGetDB( DB_SLAVE );
4048                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4049         }
4050
4051         /**
4052          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4053          *
4054          * @return bool
4055          */
4056         public function isBigDeletion() {
4057                 global $wgDeleteRevisionsLimit;
4058
4059                 if ( !$wgDeleteRevisionsLimit ) {
4060                         return false;
4061                 }
4062
4063                 $revCount = $this->estimateRevisionCount();
4064                 return $revCount > $wgDeleteRevisionsLimit;
4065         }
4066
4067         /**
4068          * Get the  approximate revision count of this page.
4069          *
4070          * @return int
4071          */
4072         public function estimateRevisionCount() {
4073                 if ( !$this->exists() ) {
4074                         return 0;
4075                 }
4076
4077                 if ( $this->mEstimateRevisions === null ) {
4078                         $dbr = wfGetDB( DB_SLAVE );
4079                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4080                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4081                 }
4082
4083                 return $this->mEstimateRevisions;
4084         }
4085
4086         /**
4087          * Get the number of revisions between the given revision.
4088          * Used for diffs and other things that really need it.
4089          *
4090          * @param $old int|Revision Old revision or rev ID (first before range)
4091          * @param $new int|Revision New revision or rev ID (first after range)
4092          * @return Int Number of revisions between these revisions.
4093          */
4094         public function countRevisionsBetween( $old, $new ) {
4095                 if ( !( $old instanceof Revision ) ) {
4096                         $old = Revision::newFromTitle( $this, (int)$old );
4097                 }
4098                 if ( !( $new instanceof Revision ) ) {
4099                         $new = Revision::newFromTitle( $this, (int)$new );
4100                 }
4101                 if ( !$old || !$new ) {
4102                         return 0; // nothing to compare
4103                 }
4104                 $dbr = wfGetDB( DB_SLAVE );
4105                 return (int)$dbr->selectField( 'revision', 'count(*)',
4106                         array(
4107                                 'rev_page' => $this->getArticleID(),
4108                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4109                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4110                         ),
4111                         __METHOD__
4112                 );
4113         }
4114
4115         /**
4116          * Get the number of authors between the given revision IDs.
4117          * Used for diffs and other things that really need it.
4118          *
4119          * @param $old int|Revision Old revision or rev ID (first before range)
4120          * @param $new int|Revision New revision or rev ID (first after range)
4121          * @param $limit Int Maximum number of authors
4122          * @return Int Number of revision authors between these revisions.
4123          */
4124         public function countAuthorsBetween( $old, $new, $limit ) {
4125                 if ( !( $old instanceof Revision ) ) {
4126                         $old = Revision::newFromTitle( $this, (int)$old );
4127                 }
4128                 if ( !( $new instanceof Revision ) ) {
4129                         $new = Revision::newFromTitle( $this, (int)$new );
4130                 }
4131                 if ( !$old || !$new ) {
4132                         return 0; // nothing to compare
4133                 }
4134                 $dbr = wfGetDB( DB_SLAVE );
4135                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4136                         array(
4137                                 'rev_page' => $this->getArticleID(),
4138                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4139                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4140                         ), __METHOD__,
4141                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4142                 );
4143                 return (int)$dbr->numRows( $res );
4144         }
4145
4146         /**
4147          * Compare with another title.
4148          *
4149          * @param $title Title
4150          * @return Bool
4151          */
4152         public function equals( Title $title ) {
4153                 // Note: === is necessary for proper matching of number-like titles.
4154                 return $this->getInterwiki() === $title->getInterwiki()
4155                         && $this->getNamespace() == $title->getNamespace()
4156                         && $this->getDBkey() === $title->getDBkey();
4157         }
4158
4159         /**
4160          * Check if this title is a subpage of another title
4161          *
4162          * @param $title Title
4163          * @return Bool
4164          */
4165         public function isSubpageOf( Title $title ) {
4166                 return $this->getInterwiki() === $title->getInterwiki()
4167                         && $this->getNamespace() == $title->getNamespace()
4168                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4169         }
4170
4171         /**
4172          * Check if page exists.  For historical reasons, this function simply
4173          * checks for the existence of the title in the page table, and will
4174          * thus return false for interwiki links, special pages and the like.
4175          * If you want to know if a title can be meaningfully viewed, you should
4176          * probably call the isKnown() method instead.
4177          *
4178          * @return Bool
4179          */
4180         public function exists() {
4181                 return $this->getArticleID() != 0;
4182         }
4183
4184         /**
4185          * Should links to this title be shown as potentially viewable (i.e. as
4186          * "bluelinks"), even if there's no record by this title in the page
4187          * table?
4188          *
4189          * This function is semi-deprecated for public use, as well as somewhat
4190          * misleadingly named.  You probably just want to call isKnown(), which
4191          * calls this function internally.
4192          *
4193          * (ISSUE: Most of these checks are cheap, but the file existence check
4194          * can potentially be quite expensive.  Including it here fixes a lot of
4195          * existing code, but we might want to add an optional parameter to skip
4196          * it and any other expensive checks.)
4197          *
4198          * @return Bool
4199          */
4200         public function isAlwaysKnown() {
4201                 $isKnown = null;
4202
4203                 /**
4204                  * Allows overriding default behaviour for determining if a page exists.
4205                  * If $isKnown is kept as null, regular checks happen. If it's
4206                  * a boolean, this value is returned by the isKnown method.
4207                  *
4208                  * @since 1.20
4209                  *
4210                  * @param Title $title
4211                  * @param boolean|null $isKnown
4212                  */
4213                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4214
4215                 if ( !is_null( $isKnown ) ) {
4216                         return $isKnown;
4217                 }
4218
4219                 if ( $this->mInterwiki != '' ) {
4220                         return true;  // any interwiki link might be viewable, for all we know
4221                 }
4222
4223                 switch( $this->mNamespace ) {
4224                         case NS_MEDIA:
4225                         case NS_FILE:
4226                                 // file exists, possibly in a foreign repo
4227                                 return (bool)wfFindFile( $this );
4228                         case NS_SPECIAL:
4229                                 // valid special page
4230                                 return SpecialPageFactory::exists( $this->getDBkey() );
4231                         case NS_MAIN:
4232                                 // selflink, possibly with fragment
4233                                 return $this->mDbkeyform == '';
4234                         case NS_MEDIAWIKI:
4235                                 // known system message
4236                                 return $this->hasSourceText() !== false;
4237                         default:
4238                                 return false;
4239                 }
4240         }
4241
4242         /**
4243          * Does this title refer to a page that can (or might) be meaningfully
4244          * viewed?  In particular, this function may be used to determine if
4245          * links to the title should be rendered as "bluelinks" (as opposed to
4246          * "redlinks" to non-existent pages).
4247          * Adding something else to this function will cause inconsistency
4248          * since LinkHolderArray calls isAlwaysKnown() and does its own
4249          * page existence check.
4250          *
4251          * @return Bool
4252          */
4253         public function isKnown() {
4254                 return $this->isAlwaysKnown() || $this->exists();
4255         }
4256
4257         /**
4258          * Does this page have source text?
4259          *
4260          * @return Boolean
4261          */
4262         public function hasSourceText() {
4263                 if ( $this->exists() ) {
4264                         return true;
4265                 }
4266
4267                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4268                         // If the page doesn't exist but is a known system message, default
4269                         // message content will be displayed, same for language subpages-
4270                         // Use always content language to avoid loading hundreds of languages
4271                         // to get the link color.
4272                         global $wgContLang;
4273                         list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4274                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4275                         return $message->exists();
4276                 }
4277
4278                 return false;
4279         }
4280
4281         /**
4282          * Get the default message text or false if the message doesn't exist
4283          *
4284          * @return String or false
4285          */
4286         public function getDefaultMessageText() {
4287                 global $wgContLang;
4288
4289                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4290                         return false;
4291                 }
4292
4293                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4294                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4295
4296                 if ( $message->exists() ) {
4297                         return $message->plain();
4298                 } else {
4299                         return false;
4300                 }
4301         }
4302
4303         /**
4304          * Updates page_touched for this page; called from LinksUpdate.php
4305          *
4306          * @return Bool true if the update succeded
4307          */
4308         public function invalidateCache() {
4309                 if ( wfReadOnly() ) {
4310                         return false;
4311                 }
4312                 $dbw = wfGetDB( DB_MASTER );
4313                 $success = $dbw->update(
4314                         'page',
4315                         array( 'page_touched' => $dbw->timestamp() ),
4316                         $this->pageCond(),
4317                         __METHOD__
4318                 );
4319                 HTMLFileCache::clearFileCache( $this );
4320                 return $success;
4321         }
4322
4323         /**
4324          * Update page_touched timestamps and send squid purge messages for
4325          * pages linking to this title. May be sent to the job queue depending
4326          * on the number of links. Typically called on create and delete.
4327          */
4328         public function touchLinks() {
4329                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4330                 $u->doUpdate();
4331
4332                 if ( $this->getNamespace() == NS_CATEGORY ) {
4333                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4334                         $u->doUpdate();
4335                 }
4336         }
4337
4338         /**
4339          * Get the last touched timestamp
4340          *
4341          * @param $db DatabaseBase: optional db
4342          * @return String last-touched timestamp
4343          */
4344         public function getTouched( $db = null ) {
4345                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4346                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4347                 return $touched;
4348         }
4349
4350         /**
4351          * Get the timestamp when this page was updated since the user last saw it.
4352          *
4353          * @param $user User
4354          * @return String|Null
4355          */
4356         public function getNotificationTimestamp( $user = null ) {
4357                 global $wgUser, $wgShowUpdatedMarker;
4358                 // Assume current user if none given
4359                 if ( !$user ) {
4360                         $user = $wgUser;
4361                 }
4362                 // Check cache first
4363                 $uid = $user->getId();
4364                 // avoid isset here, as it'll return false for null entries
4365                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4366                         return $this->mNotificationTimestamp[$uid];
4367                 }
4368                 if ( !$uid || !$wgShowUpdatedMarker ) {
4369                         return $this->mNotificationTimestamp[$uid] = false;
4370                 }
4371                 // Don't cache too much!
4372                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4373                         $this->mNotificationTimestamp = array();
4374                 }
4375                 $dbr = wfGetDB( DB_SLAVE );
4376                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4377                         'wl_notificationtimestamp',
4378                         array(
4379                                 'wl_user' => $user->getId(),
4380                                 'wl_namespace' => $this->getNamespace(),
4381                                 'wl_title' => $this->getDBkey(),
4382                         ),
4383                         __METHOD__
4384                 );
4385                 return $this->mNotificationTimestamp[$uid];
4386         }
4387
4388         /**
4389          * Generate strings used for xml 'id' names in monobook tabs
4390          *
4391          * @param $prepend string defaults to 'nstab-'
4392          * @return String XML 'id' name
4393          */
4394         public function getNamespaceKey( $prepend = 'nstab-' ) {
4395                 global $wgContLang;
4396                 // Gets the subject namespace if this title
4397                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4398                 // Checks if cononical namespace name exists for namespace
4399                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4400                         // Uses canonical namespace name
4401                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4402                 } else {
4403                         // Uses text of namespace
4404                         $namespaceKey = $this->getSubjectNsText();
4405                 }
4406                 // Makes namespace key lowercase
4407                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4408                 // Uses main
4409                 if ( $namespaceKey == '' ) {
4410                         $namespaceKey = 'main';
4411                 }
4412                 // Changes file to image for backwards compatibility
4413                 if ( $namespaceKey == 'file' ) {
4414                         $namespaceKey = 'image';
4415                 }
4416                 return $prepend . $namespaceKey;
4417         }
4418
4419         /**
4420          * Get all extant redirects to this Title
4421          *
4422          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4423          * @return Array of Title redirects to this title
4424          */
4425         public function getRedirectsHere( $ns = null ) {
4426                 $redirs = array();
4427
4428                 $dbr = wfGetDB( DB_SLAVE );
4429                 $where = array(
4430                         'rd_namespace' => $this->getNamespace(),
4431                         'rd_title' => $this->getDBkey(),
4432                         'rd_from = page_id'
4433                 );
4434                 if ( !is_null( $ns ) ) {
4435                         $where['page_namespace'] = $ns;
4436                 }
4437
4438                 $res = $dbr->select(
4439                         array( 'redirect', 'page' ),
4440                         array( 'page_namespace', 'page_title' ),
4441                         $where,
4442                         __METHOD__
4443                 );
4444
4445                 foreach ( $res as $row ) {
4446                         $redirs[] = self::newFromRow( $row );
4447                 }
4448                 return $redirs;
4449         }
4450
4451         /**
4452          * Check if this Title is a valid redirect target
4453          *
4454          * @return Bool
4455          */
4456         public function isValidRedirectTarget() {
4457                 global $wgInvalidRedirectTargets;
4458
4459                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4460                 if ( $this->isSpecial( 'Userlogout' ) ) {
4461                         return false;
4462                 }
4463
4464                 foreach ( $wgInvalidRedirectTargets as $target ) {
4465                         if ( $this->isSpecial( $target ) ) {
4466                                 return false;
4467                         }
4468                 }
4469
4470                 return true;
4471         }
4472
4473         /**
4474          * Get a backlink cache object
4475          *
4476          * @return BacklinkCache
4477          */
4478         function getBacklinkCache() {
4479                 if ( is_null( $this->mBacklinkCache ) ) {
4480                         $this->mBacklinkCache = new BacklinkCache( $this );
4481                 }
4482                 return $this->mBacklinkCache;
4483         }
4484
4485         /**
4486          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4487          *
4488          * @return Boolean
4489          */
4490         public function canUseNoindex() {
4491                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4492
4493                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4494                         ? $wgContentNamespaces
4495                         : $wgExemptFromUserRobotsControl;
4496
4497                 return !in_array( $this->mNamespace, $bannedNamespaces );
4498
4499         }
4500
4501         /**
4502          * Returns the raw sort key to be used for categories, with the specified
4503          * prefix.  This will be fed to Collation::getSortKey() to get a
4504          * binary sortkey that can be used for actual sorting.
4505          *
4506          * @param $prefix string The prefix to be used, specified using
4507          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4508          *   prefix.
4509          * @return string
4510          */
4511         public function getCategorySortkey( $prefix = '' ) {
4512                 $unprefixed = $this->getText();
4513
4514                 // Anything that uses this hook should only depend
4515                 // on the Title object passed in, and should probably
4516                 // tell the users to run updateCollations.php --force
4517                 // in order to re-sort existing category relations.
4518                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4519                 if ( $prefix !== '' ) {
4520                         # Separate with a line feed, so the unprefixed part is only used as
4521                         # a tiebreaker when two pages have the exact same prefix.
4522                         # In UCA, tab is the only character that can sort above LF
4523                         # so we strip both of them from the original prefix.
4524                         $prefix = strtr( $prefix, "\n\t", '  ' );
4525                         return "$prefix\n$unprefixed";
4526                 }
4527                 return $unprefixed;
4528         }
4529
4530         /**
4531          * Get the language in which the content of this page is written.
4532          * Defaults to $wgContLang, but in certain cases it can be e.g.
4533          * $wgLang (such as special pages, which are in the user language).
4534          *
4535          * @since 1.18
4536          * @return Language
4537          */
4538         public function getPageLanguage() {
4539                 global $wgLang;
4540                 if ( $this->isSpecialPage() ) {
4541                         // special pages are in the user language
4542                         return $wgLang;
4543                 } elseif ( $this->isCssOrJsPage() || $this->isCssJsSubpage() ) {
4544                         // css/js should always be LTR and is, in fact, English
4545                         return wfGetLangObj( 'en' );
4546                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4547                         // Parse mediawiki messages with correct target language
4548                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4549                         return wfGetLangObj( $lang );
4550                 }
4551                 global $wgContLang;
4552                 // If nothing special, it should be in the wiki content language
4553                 $pageLang = $wgContLang;
4554                 // Hook at the end because we don't want to override the above stuff
4555                 wfRunHooks( 'PageContentLanguage', array( $this, &$pageLang, $wgLang ) );
4556                 return wfGetLangObj( $pageLang );
4557         }
4558 }