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 $mHasSubpage;                 // /< Whether a page has any subpages
  89         // @}
  90
  91         /**
  92          * Constructor
  93          */
  94         /*protected*/ function __construct() { }
  95
  96         /**
  97          * Create a new Title from a prefixed DB key
  98          *
  99          * @param string $key the database key, which has underscores
 100          *      instead of spaces, possibly including namespace and
 101          *      interwiki prefixes
 102          * @return Title, or NULL on an error
 103          */
 104         public static function newFromDBkey( $key ) {
 105                 $t = new Title();
 106                 $t->mDbkeyform = $key;
 107                 if ( $t->secureAndSplit() ) {
 108                         return $t;
 109                 } else {
 110                         return null;
 111                 }
 112         }
 113
 114         /**
 115          * Create a new Title from text, such as what one would find in a link. De-
 116          * codes any HTML entities in the text.
 117          *
 118          * @param string $text the link text; spaces, prefixes, and an
 119          *   initial ':' indicating the main namespace are accepted.
 120          * @param int $defaultNamespace the namespace to use if none is specified
 121          *   by a prefix.  If you want to force a specific namespace even if
 122          *   $text might begin with a namespace prefix, use makeTitle() or
 123          *   makeTitleSafe().
 124          * @throws MWException
 125          * @return Title|null - Title or null on an error.
 126          */
 127         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 128                 if ( is_object( $text ) ) {
 129                         throw new MWException( 'Title::newFromText given an object' );
 130                 }
 131
 132                 /**
 133                  * Wiki pages often contain multiple links to the same page.
 134                  * Title normalization and parsing can become expensive on
 135                  * pages with many links, so we can save a little time by
 136                  * caching them.
 137                  *
 138                  * In theory these are value objects and won't get changed...
 139                  */
 140                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 141                         return Title::$titleCache[$text];
 142                 }
 143
 144                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 145                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 146
 147                 $t = new Title();
 148                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 149                 $t->mDefaultNamespace = $defaultNamespace;
 150
 151                 static $cachedcount = 0;
 152                 if ( $t->secureAndSplit() ) {
 153                         if ( $defaultNamespace == NS_MAIN ) {
 154                                 if ( $cachedcount >= self::CACHE_MAX ) {
 155                                         # Avoid memory leaks on mass operations...
 156                                         Title::$titleCache = array();
 157                                         $cachedcount = 0;
 158                                 }
 159                                 $cachedcount++;
 160                                 Title::$titleCache[$text] =& $t;
 161                         }
 162                         return $t;
 163                 } else {
 164                         $ret = null;
 165                         return $ret;
 166                 }
 167         }
 168
 169         /**
 170          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 171          *
 172          * Example of wrong and broken code:
 173          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Example of right code:
 176          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 177          *
 178          * Create a new Title from URL-encoded text. Ensures that
 179          * the given title's length does not exceed the maximum.
 180          *
 181          * @param string $url the title, as might be taken from a URL
 182          * @return Title the new object, or NULL on an error
 183          */
 184         public static function newFromURL( $url ) {
 185                 $t = new Title();
 186
 187                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 188                 # but some URLs used it as a space replacement and they still come
 189                 # from some external search tools.
 190                 if ( strpos( self::legalChars(), '+' ) === false ) {
 191                         $url = str_replace( '+', ' ', $url );
 192                 }
 193
 194                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 195                 if ( $t->secureAndSplit() ) {
 196                         return $t;
 197                 } else {
 198                         return null;
 199                 }
 200         }
 201
 202         /**
 203          * Returns a list of fields that are to be selected for initializing Title objects or LinkCache entries.
 204          * Uses $wgContentHandlerUseDB to determine whether to include page_content_model.
 205          *
 206          * @return array
 207          */
 208         protected static function getSelectFields() {
 209                 global $wgContentHandlerUseDB;
 210
 211                 $fields = array(
 212                         'page_namespace', 'page_title', 'page_id',
 213                         'page_len', 'page_is_redirect', 'page_latest',
 214                 );
 215
 216                 if ( $wgContentHandlerUseDB ) {
 217                         $fields[] = 'page_content_model';
 218                 }
 219
 220                 return $fields;
 221         }
 222
 223         /**
 224          * Create a new Title from an article ID
 225          *
 226          * @param int $id the page_id corresponding to the Title to create
 227          * @param int $flags use Title::GAID_FOR_UPDATE to use master
 228          * @return Title the new object, or NULL on an error
 229          */
 230         public static function newFromID( $id, $flags = 0 ) {
 231                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 232                 $row = $db->selectRow(
 233                         'page',
 234                         self::getSelectFields(),
 235                         array( 'page_id' => $id ),
 236                         __METHOD__
 237                 );
 238                 if ( $row !== false ) {
 239                         $title = Title::newFromRow( $row );
 240                 } else {
 241                         $title = null;
 242                 }
 243                 return $title;
 244         }
 245
 246         /**
 247          * Make an array of titles from an array of IDs
 248          *
 249          * @param array $ids of Int Array of IDs
 250          * @return Array of Titles
 251          */
 252         public static function newFromIDs( $ids ) {
 253                 if ( !count( $ids ) ) {
 254                         return array();
 255                 }
 256                 $dbr = wfGetDB( DB_SLAVE );
 257
 258                 $res = $dbr->select(
 259                         'page',
 260                         self::getSelectFields(),
 261                         array( 'page_id' => $ids ),
 262                         __METHOD__
 263                 );
 264
 265                 $titles = array();
 266                 foreach ( $res as $row ) {
 267                         $titles[] = Title::newFromRow( $row );
 268                 }
 269                 return $titles;
 270         }
 271
 272         /**
 273          * Make a Title object from a DB row
 274          *
 275          * @param $row Object database row (needs at least page_title,page_namespace)
 276          * @return Title corresponding Title
 277          */
 278         public static function newFromRow( $row ) {
 279                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 280                 $t->loadFromRow( $row );
 281                 return $t;
 282         }
 283
 284         /**
 285          * Load Title object fields from a DB row.
 286          * If false is given, the title will be treated as non-existing.
 287          *
 288          * @param $row Object|bool database row
 289          */
 290         public function loadFromRow( $row ) {
 291                 if ( $row ) { // page found
 292                         if ( isset( $row->page_id ) )
 293                                 $this->mArticleID = (int)$row->page_id;
 294                         if ( isset( $row->page_len ) )
 295                                 $this->mLength = (int)$row->page_len;
 296                         if ( isset( $row->page_is_redirect ) )
 297                                 $this->mRedirect = (bool)$row->page_is_redirect;
 298                         if ( isset( $row->page_latest ) )
 299                                 $this->mLatestID = (int)$row->page_latest;
 300                         if ( isset( $row->page_content_model ) )
 301                                 $this->mContentModel = strval( $row->page_content_model );
 302                         else
 303                                 $this->mContentModel = false; # initialized lazily in getContentModel()
 304                 } else { // page not found
 305                         $this->mArticleID = 0;
 306                         $this->mLength = 0;
 307                         $this->mRedirect = false;
 308                         $this->mLatestID = 0;
 309                         $this->mContentModel = false; # initialized lazily in getContentModel()
 310                 }
 311         }
 312
 313         /**
 314          * Create a new Title from a namespace index and a DB key.
 315          * It's assumed that $ns and $title are *valid*, for instance when
 316          * they came directly from the database or a special page name.
 317          * For convenience, spaces are converted to underscores so that
 318          * eg user_text fields can be used directly.
 319          *
 320          * @param int $ns the namespace of the article
 321          * @param string $title the unprefixed database key form
 322          * @param string $fragment the link fragment (after the "#")
 323          * @param string $interwiki the interwiki prefix
 324          * @return Title the new object
 325          */
 326         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 327                 $t = new Title();
 328                 $t->mInterwiki = $interwiki;
 329                 $t->mFragment = $fragment;
 330                 $t->mNamespace = $ns = intval( $ns );
 331                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 332                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 333                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 334                 $t->mTextform = str_replace( '_', ' ', $title );
 335                 $t->mContentModel = false; # initialized lazily in getContentModel()
 336                 return $t;
 337         }
 338
 339         /**
 340          * Create a new Title from a namespace index and a DB key.
 341          * The parameters will be checked for validity, which is a bit slower
 342          * than makeTitle() but safer for user-provided data.
 343          *
 344          * @param int $ns the namespace of the article
 345          * @param string $title database key form
 346          * @param string $fragment the link fragment (after the "#")
 347          * @param string $interwiki interwiki prefix
 348          * @return Title the new object, or NULL on an error
 349          */
 350         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 351                 if ( !MWNamespace::exists( $ns ) ) {
 352                         return null;
 353                 }
 354
 355                 $t = new Title();
 356                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 357                 if ( $t->secureAndSplit() ) {
 358                         return $t;
 359                 } else {
 360                         return null;
 361                 }
 362         }
 363
 364         /**
 365          * Create a new Title for the Main Page
 366          *
 367          * @return Title the new object
 368          */
 369         public static function newMainPage() {
 370                 $title = Title::newFromText( wfMessage( 'mainpage' )->inContentLanguage()->text() );
 371                 // Don't give fatal errors if the message is broken
 372                 if ( !$title ) {
 373                         $title = Title::newFromText( 'Main Page' );
 374                 }
 375                 return $title;
 376         }
 377
 378         /**
 379          * Extract a redirect destination from a string and return the
 380          * Title, or null if the text doesn't contain a valid redirect
 381          * This will only return the very next target, useful for
 382          * the redirect table and other checks that don't need full recursion
 383          *
 384          * @param string $text Text with possible redirect
 385          * @return Title: The corresponding Title
 386          * @deprecated since 1.21, use Content::getRedirectTarget instead.
 387          */
 388         public static function newFromRedirect( $text ) {
 389                 ContentHandler::deprecated( __METHOD__, '1.21' );
 390
 391                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 392                 return $content->getRedirectTarget();
 393         }
 394
 395         /**
 396          * Extract a redirect destination from a string and return the
 397          * Title, or null if the text doesn't contain a valid redirect
 398          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 399          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 400          *
 401          * @param string $text Text with possible redirect
 402          * @return Title
 403          * @deprecated since 1.21, use Content::getUltimateRedirectTarget instead.
 404          */
 405         public static function newFromRedirectRecurse( $text ) {
 406                 ContentHandler::deprecated( __METHOD__, '1.21' );
 407
 408                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 409                 return $content->getUltimateRedirectTarget();
 410         }
 411
 412         /**
 413          * Extract a redirect destination from a string and return an
 414          * array of Titles, or null if the text doesn't contain a valid redirect
 415          * The last element in the array is the final destination after all redirects
 416          * have been resolved (up to $wgMaxRedirects times)
 417          *
 418          * @param string $text Text with possible redirect
 419          * @return Array of Titles, with the destination last
 420          * @deprecated since 1.21, use Content::getRedirectChain instead.
 421          */
 422         public static function newFromRedirectArray( $text ) {
 423                 ContentHandler::deprecated( __METHOD__, '1.21' );
 424
 425                 $content = ContentHandler::makeContent( $text, null, CONTENT_MODEL_WIKITEXT );
 426                 return $content->getRedirectChain();
 427         }
 428
 429         /**
 430          * Get the prefixed DB key associated with an ID
 431          *
 432          * @param int $id the page_id of the article
 433          * @return Title an object representing the article, or NULL if no such article was found
 434          */
 435         public static function nameOf( $id ) {
 436                 $dbr = wfGetDB( DB_SLAVE );
 437
 438                 $s = $dbr->selectRow(
 439                         'page',
 440                         array( 'page_namespace', 'page_title' ),
 441                         array( 'page_id' => $id ),
 442                         __METHOD__
 443                 );
 444                 if ( $s === false ) {
 445                         return null;
 446                 }
 447
 448                 $n = self::makeName( $s->page_namespace, $s->page_title );
 449                 return $n;
 450         }
 451
 452         /**
 453          * Get a regex character class describing the legal characters in a link
 454          *
 455          * @return String the list of characters, not delimited
 456          */
 457         public static function legalChars() {
 458                 global $wgLegalTitleChars;
 459                 return $wgLegalTitleChars;
 460         }
 461
 462         /**
 463          * Returns a simple regex that will match on characters and sequences invalid in titles.
 464          * Note that this doesn't pick up many things that could be wrong with titles, but that
 465          * replacing this regex with something valid will make many titles valid.
 466          *
 467          * @return String regex string
 468          */
 469         static function getTitleInvalidRegex() {
 470                 static $rxTc = false;
 471                 if ( !$rxTc ) {
 472                         # Matching titles will be held as illegal.
 473                         $rxTc = '/' .
 474                                 # Any character not allowed is forbidden...
 475                                 '[^' . self::legalChars() . ']' .
 476                                 # URL percent encoding sequences interfere with the ability
 477                                 # to round-trip titles -- you can't link to them consistently.
 478                                 '|%[0-9A-Fa-f]{2}' .
 479                                 # XML/HTML character references produce similar issues.
 480                                 '|&[A-Za-z0-9\x80-\xff]+;' .
 481                                 '|&#[0-9]+;' .
 482                                 '|&#x[0-9A-Fa-f]+;' .
 483                                 '/S';
 484                 }
 485
 486                 return $rxTc;
 487         }
 488
 489         /**
 490          * Get a string representation of a title suitable for
 491          * including in a search index
 492          *
 493          * @param int $ns a namespace index
 494          * @param string $title text-form main part
 495          * @return String a stripped-down title string ready for the search index
 496          */
 497         public static function indexTitle( $ns, $title ) {
 498                 global $wgContLang;
 499
 500                 $lc = SearchEngine::legalSearchChars() . '&#;';
 501                 $t = $wgContLang->normalizeForSearch( $title );
 502                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 503                 $t = $wgContLang->lc( $t );
 504
 505                 # Handle 's, s'
 506                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 507                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 508
 509                 $t = preg_replace( "/\\s+/", ' ', $t );
 510
 511                 if ( $ns == NS_FILE ) {
 512                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 513                 }
 514                 return trim( $t );
 515         }
 516
 517         /**
 518          * Make a prefixed DB key from a DB key and a namespace index
 519          *
 520          * @param int $ns numerical representation of the namespace
 521          * @param string $title the DB key form the title
 522          * @param string $fragment The link fragment (after the "#")
 523          * @param string $interwiki The interwiki prefix
 524          * @return String the prefixed form of the title
 525          */
 526         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 527                 global $wgContLang;
 528
 529                 $namespace = $wgContLang->getNsText( $ns );
 530                 $name = $namespace == '' ? $title : "$namespace:$title";
 531                 if ( strval( $interwiki ) != '' ) {
 532                         $name = "$interwiki:$name";
 533                 }
 534                 if ( strval( $fragment ) != '' ) {
 535                         $name .= '#' . $fragment;
 536                 }
 537                 return $name;
 538         }
 539
 540         /**
 541          * Escape a text fragment, say from a link, for a URL
 542          *
 543          * @param string $fragment containing a URL or link fragment (after the "#")
 544          * @return String: escaped string
 545          */
 546         static function escapeFragmentForURL( $fragment ) {
 547                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 548                 # fragments appear not to work in IE (at least up to 7) or in at least
 549                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 550                 # to care if they aren't encoded.
 551                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 552         }
 553
 554         /**
 555          * Callback for usort() to do title sorts by (namespace, title)
 556          *
 557          * @param $a Title
 558          * @param $b Title
 559          *
 560          * @return Integer: result of string comparison, or namespace comparison
 561          */
 562         public static function compare( $a, $b ) {
 563                 if ( $a->getNamespace() == $b->getNamespace() ) {
 564                         return strcmp( $a->getText(), $b->getText() );
 565                 } else {
 566                         return $a->getNamespace() - $b->getNamespace();
 567                 }
 568         }
 569
 570         /**
 571          * Determine whether the object refers to a page within
 572          * this project.
 573          *
 574          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 575          */
 576         public function isLocal() {
 577                 if ( $this->mInterwiki != '' ) {
 578                         $iw = Interwiki::fetch( $this->mInterwiki );
 579                         if ( $iw ) {
 580                                 return $iw->isLocal();
 581                         }
 582                 }
 583                 return true;
 584         }
 585
 586         /**
 587          * Is this Title interwiki?
 588          *
 589          * @return Bool
 590          */
 591         public function isExternal() {
 592                 return ( $this->mInterwiki != '' );
 593         }
 594
 595         /**
 596          * Get the interwiki prefix (or null string)
 597          *
 598          * @return String Interwiki prefix
 599          */
 600         public function getInterwiki() {
 601                 return $this->mInterwiki;
 602         }
 603
 604         /**
 605          * Determine whether the object refers to a page within
 606          * this project and is transcludable.
 607          *
 608          * @return Bool TRUE if this is transcludable
 609          */
 610         public function isTrans() {
 611                 if ( $this->mInterwiki == '' ) {
 612                         return false;
 613                 }
 614
 615                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 616         }
 617
 618         /**
 619          * Returns the DB name of the distant wiki which owns the object.
 620          *
 621          * @return String the DB name
 622          */
 623         public function getTransWikiID() {
 624                 if ( $this->mInterwiki == '' ) {
 625                         return false;
 626                 }
 627
 628                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 629         }
 630
 631         /**
 632          * Get the text form (spaces not underscores) of the main part
 633          *
 634          * @return String Main part of the title
 635          */
 636         public function getText() {
 637                 return $this->mTextform;
 638         }
 639
 640         /**
 641          * Get the URL-encoded form of the main part
 642          *
 643          * @return String Main part of the title, URL-encoded
 644          */
 645         public function getPartialURL() {
 646                 return $this->mUrlform;
 647         }
 648
 649         /**
 650          * Get the main part with underscores
 651          *
 652          * @return String: Main part of the title, with underscores
 653          */
 654         public function getDBkey() {
 655                 return $this->mDbkeyform;
 656         }
 657
 658         /**
 659          * Get the DB key with the initial letter case as specified by the user
 660          *
 661          * @return String DB key
 662          */
 663         function getUserCaseDBKey() {
 664                 return $this->mUserCaseDBKey;
 665         }
 666
 667         /**
 668          * Get the namespace index, i.e. one of the NS_xxxx constants.
 669          *
 670          * @return Integer: Namespace index
 671          */
 672         public function getNamespace() {
 673                 return $this->mNamespace;
 674         }
 675
 676         /**
 677          * Get the page's content model id, see the CONTENT_MODEL_XXX constants.
 678          *
 679          * @throws MWException
 680          * @return String: Content model id
 681          */
 682         public function getContentModel() {
 683                 if ( !$this->mContentModel ) {
 684                         $linkCache = LinkCache::singleton();
 685                         $this->mContentModel = $linkCache->getGoodLinkFieldObj( $this, 'model' );
 686                 }
 687
 688                 if ( !$this->mContentModel ) {
 689                         $this->mContentModel = ContentHandler::getDefaultModelFor( $this );
 690                 }
 691
 692                 if( !$this->mContentModel ) {
 693                         throw new MWException( 'Failed to determine content model!' );
 694                 }
 695
 696                 return $this->mContentModel;
 697         }
 698
 699         /**
 700          * Convenience method for checking a title's content model name
 701          *
 702          * @param string $id The content model ID (use the CONTENT_MODEL_XXX constants).
 703          * @return Boolean true if $this->getContentModel() == $id
 704          */
 705         public function hasContentModel( $id ) {
 706                 return $this->getContentModel() == $id;
 707         }
 708
 709         /**
 710          * Get the namespace text
 711          *
 712          * @return String: Namespace text
 713          */
 714         public function getNsText() {
 715                 global $wgContLang;
 716
 717                 if ( $this->mInterwiki != '' ) {
 718                         // This probably shouldn't even happen. ohh man, oh yuck.
 719                         // But for interwiki transclusion it sometimes does.
 720                         // Shit. Shit shit shit.
 721                         //
 722                         // Use the canonical namespaces if possible to try to
 723                         // resolve a foreign namespace.
 724                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 725                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 726                         }
 727                 }
 728
 729                 if ( $wgContLang->needsGenderDistinction() &&
 730                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 731                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 732                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 733                 }
 734
 735                 return $wgContLang->getNsText( $this->mNamespace );
 736         }
 737
 738         /**
 739          * Get the namespace text of the subject (rather than talk) page
 740          *
 741          * @return String Namespace text
 742          */
 743         public function getSubjectNsText() {
 744                 global $wgContLang;
 745                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 746         }
 747
 748         /**
 749          * Get the namespace text of the talk page
 750          *
 751          * @return String Namespace text
 752          */
 753         public function getTalkNsText() {
 754                 global $wgContLang;
 755                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 756         }
 757
 758         /**
 759          * Could this title have a corresponding talk page?
 760          *
 761          * @return Bool TRUE or FALSE
 762          */
 763         public function canTalk() {
 764                 return( MWNamespace::canTalk( $this->mNamespace ) );
 765         }
 766
 767         /**
 768          * Is this in a namespace that allows actual pages?
 769          *
 770          * @return Bool
 771          * @internal note -- uses hardcoded namespace index instead of constants
 772          */
 773         public function canExist() {
 774                 return $this->mNamespace >= NS_MAIN;
 775         }
 776
 777         /**
 778          * Can this title be added to a user's watchlist?
 779          *
 780          * @return Bool TRUE or FALSE
 781          */
 782         public function isWatchable() {
 783                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
 784         }
 785
 786         /**
 787          * Returns true if this is a special page.
 788          *
 789          * @return boolean
 790          */
 791         public function isSpecialPage() {
 792                 return $this->getNamespace() == NS_SPECIAL;
 793         }
 794
 795         /**
 796          * Returns true if this title resolves to the named special page
 797          *
 798          * @param string $name The special page name
 799          * @return boolean
 800          */
 801         public function isSpecial( $name ) {
 802                 if ( $this->isSpecialPage() ) {
 803                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
 804                         if ( $name == $thisName ) {
 805                                 return true;
 806                         }
 807                 }
 808                 return false;
 809         }
 810
 811         /**
 812          * If the Title refers to a special page alias which is not the local default, resolve
 813          * the alias, and localise the name as necessary.  Otherwise, return $this
 814          *
 815          * @return Title
 816          */
 817         public function fixSpecialName() {
 818                 if ( $this->isSpecialPage() ) {
 819                         list( $canonicalName, $par ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
 820                         if ( $canonicalName ) {
 821                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName, $par );
 822                                 if ( $localName != $this->mDbkeyform ) {
 823                                         return Title::makeTitle( NS_SPECIAL, $localName );
 824                                 }
 825                         }
 826                 }
 827                 return $this;
 828         }
 829
 830         /**
 831          * Returns true if the title is inside the specified namespace.
 832          *
 833          * Please make use of this instead of comparing to getNamespace()
 834          * This function is much more resistant to changes we may make
 835          * to namespaces than code that makes direct comparisons.
 836          * @param int $ns The namespace
 837          * @return bool
 838          * @since 1.19
 839          */
 840         public function inNamespace( $ns ) {
 841                 return MWNamespace::equals( $this->getNamespace(), $ns );
 842         }
 843
 844         /**
 845          * Returns true if the title is inside one of the specified namespaces.
 846          *
 847          * @param ...$namespaces The namespaces to check for
 848          * @return bool
 849          * @since 1.19
 850          */
 851         public function inNamespaces( /* ... */ ) {
 852                 $namespaces = func_get_args();
 853                 if ( count( $namespaces ) > 0 && is_array( $namespaces[0] ) ) {
 854                         $namespaces = $namespaces[0];
 855                 }
 856
 857                 foreach ( $namespaces as $ns ) {
 858                         if ( $this->inNamespace( $ns ) ) {
 859                                 return true;
 860                         }
 861                 }
 862
 863                 return false;
 864         }
 865
 866         /**
 867          * Returns true if the title has the same subject namespace as the
 868          * namespace specified.
 869          * For example this method will take NS_USER and return true if namespace
 870          * is either NS_USER or NS_USER_TALK since both of them have NS_USER
 871          * as their subject namespace.
 872          *
 873          * This is MUCH simpler than individually testing for equivalence
 874          * against both NS_USER and NS_USER_TALK, and is also forward compatible.
 875          * @since 1.19
 876          * @param $ns int
 877          * @return bool
 878          */
 879         public function hasSubjectNamespace( $ns ) {
 880                 return MWNamespace::subjectEquals( $this->getNamespace(), $ns );
 881         }
 882
 883         /**
 884          * Is this Title in a namespace which contains content?
 885          * In other words, is this a content page, for the purposes of calculating
 886          * statistics, etc?
 887          *
 888          * @return Boolean
 889          */
 890         public function isContentPage() {
 891                 return MWNamespace::isContent( $this->getNamespace() );
 892         }
 893
 894         /**
 895          * Would anybody with sufficient privileges be able to move this page?
 896          * Some pages just aren't movable.
 897          *
 898          * @return Bool TRUE or FALSE
 899          */
 900         public function isMovable() {
 901                 if ( !MWNamespace::isMovable( $this->getNamespace() ) || $this->getInterwiki() != '' ) {
 902                         // Interwiki title or immovable namespace. Hooks don't get to override here
 903                         return false;
 904                 }
 905
 906                 $result = true;
 907                 wfRunHooks( 'TitleIsMovable', array( $this, &$result ) );
 908                 return $result;
 909         }
 910
 911         /**
 912          * Is this the mainpage?
 913          * @note Title::newFromText seems to be sufficiently optimized by the title
 914          * cache that we don't need to over-optimize by doing direct comparisons and
 915          * accidentally creating new bugs where $title->equals( Title::newFromText() )
 916          * ends up reporting something differently than $title->isMainPage();
 917          *
 918          * @since 1.18
 919          * @return Bool
 920          */
 921         public function isMainPage() {
 922                 return $this->equals( Title::newMainPage() );
 923         }
 924
 925         /**
 926          * Is this a subpage?
 927          *
 928          * @return Bool
 929          */
 930         public function isSubpage() {
 931                 return MWNamespace::hasSubpages( $this->mNamespace )
 932                         ? strpos( $this->getText(), '/' ) !== false
 933                         : false;
 934         }
 935
 936         /**
 937          * Is this a conversion table for the LanguageConverter?
 938          *
 939          * @return Bool
 940          */
 941         public function isConversionTable() {
 942                 //@todo: ConversionTable should become a separate content model.
 943
 944                 return $this->getNamespace() == NS_MEDIAWIKI &&
 945                         strpos( $this->getText(), 'Conversiontable/' ) === 0;
 946         }
 947
 948         /**
 949          * Does that page contain wikitext, or it is JS, CSS or whatever?
 950          *
 951          * @return Bool
 952          */
 953         public function isWikitextPage() {
 954                 return $this->hasContentModel( CONTENT_MODEL_WIKITEXT );
 955         }
 956
 957         /**
 958          * Could this page contain custom CSS or JavaScript for the global UI.
 959          * This is generally true for pages in the MediaWiki namespace having CONTENT_MODEL_CSS
 960          * or CONTENT_MODEL_JAVASCRIPT.
 961          *
 962          * This method does *not* return true for per-user JS/CSS. Use isCssJsSubpage() for that!
 963          *
 964          * Note that this method should not return true for pages that contain and show "inactive" CSS or JS.
 965          *
 966          * @return Bool
 967          */
 968         public function isCssOrJsPage() {
 969                 $isCssOrJsPage = NS_MEDIAWIKI == $this->mNamespace
 970                         && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 971                                 || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
 972
 973                 #NOTE: this hook is also called in ContentHandler::getDefaultModel. It's called here again to make sure
 974                 #      hook functions can force this method to return true even outside the mediawiki namespace.
 975
 976                 wfRunHooks( 'TitleIsCssOrJsPage', array( $this, &$isCssOrJsPage ) );
 977
 978                 return $isCssOrJsPage;
 979         }
 980
 981         /**
 982          * Is this a .css or .js subpage of a user page?
 983          * @return Bool
 984          */
 985         public function isCssJsSubpage() {
 986                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
 987                                 && ( $this->hasContentModel( CONTENT_MODEL_CSS )
 988                                         || $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) ) );
 989         }
 990
 991         /**
 992          * Trim down a .css or .js subpage title to get the corresponding skin name
 993          *
 994          * @return string containing skin name from .css or .js subpage title
 995          */
 996         public function getSkinFromCssJsSubpage() {
 997                 $subpage = explode( '/', $this->mTextform );
 998                 $subpage = $subpage[count( $subpage ) - 1];
 999                 $lastdot = strrpos( $subpage, '.' );
1000                 if ( $lastdot === false )
1001                         return $subpage; # Never happens: only called for names ending in '.css' or '.js'
1002                 return substr( $subpage, 0, $lastdot );
1003         }
1004
1005         /**
1006          * Is this a .css subpage of a user page?
1007          *
1008          * @return Bool
1009          */
1010         public function isCssSubpage() {
1011                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1012                         && $this->hasContentModel( CONTENT_MODEL_CSS ) );
1013         }
1014
1015         /**
1016          * Is this a .js subpage of a user page?
1017          *
1018          * @return Bool
1019          */
1020         public function isJsSubpage() {
1021                 return ( NS_USER == $this->mNamespace && $this->isSubpage()
1022                         && $this->hasContentModel( CONTENT_MODEL_JAVASCRIPT ) );
1023         }
1024
1025         /**
1026          * Is this a talk page of some sort?
1027          *
1028          * @return Bool
1029          */
1030         public function isTalkPage() {
1031                 return MWNamespace::isTalk( $this->getNamespace() );
1032         }
1033
1034         /**
1035          * Get a Title object associated with the talk page of this article
1036          *
1037          * @return Title the object for the talk page
1038          */
1039         public function getTalkPage() {
1040                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
1041         }
1042
1043         /**
1044          * Get a title object associated with the subject page of this
1045          * talk page
1046          *
1047          * @return Title the object for the subject page
1048          */
1049         public function getSubjectPage() {
1050                 // Is this the same title?
1051                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
1052                 if ( $this->getNamespace() == $subjectNS ) {
1053                         return $this;
1054                 }
1055                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
1056         }
1057
1058         /**
1059          * Get the default namespace index, for when there is no namespace
1060          *
1061          * @return Int Default namespace index
1062          */
1063         public function getDefaultNamespace() {
1064                 return $this->mDefaultNamespace;
1065         }
1066
1067         /**
1068          * Get title for search index
1069          *
1070          * @return String a stripped-down title string ready for the
1071          *  search index
1072          */
1073         public function getIndexTitle() {
1074                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
1075         }
1076
1077         /**
1078          * Get the Title fragment (i.e.\ the bit after the #) in text form
1079          *
1080          * @return String Title fragment
1081          */
1082         public function getFragment() {
1083                 return $this->mFragment;
1084         }
1085
1086         /**
1087          * Get the fragment in URL form, including the "#" character if there is one
1088          * @return String Fragment in URL form
1089          */
1090         public function getFragmentForURL() {
1091                 if ( $this->mFragment == '' ) {
1092                         return '';
1093                 } else {
1094                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
1095                 }
1096         }
1097
1098         /**
1099          * Set the fragment for this title. Removes the first character from the
1100          * specified fragment before setting, so it assumes you're passing it with
1101          * an initial "#".
1102          *
1103          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
1104          * Still in active use privately.
1105          *
1106          * @param string $fragment text
1107          */
1108         public function setFragment( $fragment ) {
1109                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
1110         }
1111
1112         /**
1113          * Prefix some arbitrary text with the namespace or interwiki prefix
1114          * of this object
1115          *
1116          * @param string $name the text
1117          * @return String the prefixed text
1118          * @private
1119          */
1120         private function prefix( $name ) {
1121                 $p = '';
1122                 if ( $this->mInterwiki != '' ) {
1123                         $p = $this->mInterwiki . ':';
1124                 }
1125
1126                 if ( 0 != $this->mNamespace ) {
1127                         $p .= $this->getNsText() . ':';
1128                 }
1129                 return $p . $name;
1130         }
1131
1132         /**
1133          * Get the prefixed database key form
1134          *
1135          * @return String the prefixed title, with underscores and
1136          *  any interwiki and namespace prefixes
1137          */
1138         public function getPrefixedDBkey() {
1139                 $s = $this->prefix( $this->mDbkeyform );
1140                 $s = str_replace( ' ', '_', $s );
1141                 return $s;
1142         }
1143
1144         /**
1145          * Get the prefixed title with spaces.
1146          * This is the form usually used for display
1147          *
1148          * @return String the prefixed title, with spaces
1149          */
1150         public function getPrefixedText() {
1151                 // @todo FIXME: Bad usage of empty() ?
1152                 if ( empty( $this->mPrefixedText ) ) {
1153                         $s = $this->prefix( $this->mTextform );
1154                         $s = str_replace( '_', ' ', $s );
1155                         $this->mPrefixedText = $s;
1156                 }
1157                 return $this->mPrefixedText;
1158         }
1159
1160         /**
1161          * Return a string representation of this title
1162          *
1163          * @return String representation of this title
1164          */
1165         public function __toString() {
1166                 return $this->getPrefixedText();
1167         }
1168
1169         /**
1170          * Get the prefixed title with spaces, plus any fragment
1171          * (part beginning with '#')
1172          *
1173          * @return String the prefixed title, with spaces and the fragment, including '#'
1174          */
1175         public function getFullText() {
1176                 $text = $this->getPrefixedText();
1177                 if ( $this->mFragment != '' ) {
1178                         $text .= '#' . $this->mFragment;
1179                 }
1180                 return $text;
1181         }
1182
1183         /**
1184          * Get the root page name text without a namespace, i.e. the leftmost part before any slashes
1185          *
1186          * @par Example:
1187          * @code
1188          * Title::newFromText('User:Foo/Bar/Baz')->getRootText();
1189          * # returns: 'Foo'
1190          * @endcode
1191          *
1192          * @return String Root name
1193          * @since 1.20
1194          */
1195         public function getRootText() {
1196                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1197                         return $this->getText();
1198                 }
1199
1200                 return strtok( $this->getText(), '/' );
1201         }
1202
1203         /**
1204          * Get the root page name title, i.e. the leftmost part before any slashes
1205          *
1206          * @par Example:
1207          * @code
1208          * Title::newFromText('User:Foo/Bar/Baz')->getRootTitle();
1209          * # returns: Title{User:Foo}
1210          * @endcode
1211          *
1212          * @return Title Root title
1213          * @since 1.20
1214          */
1215         public function getRootTitle() {
1216                 return Title::makeTitle( $this->getNamespace(), $this->getRootText() );
1217         }
1218
1219         /**
1220          * Get the base page name without a namespace, i.e. the part before the subpage name
1221          *
1222          * @par Example:
1223          * @code
1224          * Title::newFromText('User:Foo/Bar/Baz')->getBaseText();
1225          * # returns: 'Foo/Bar'
1226          * @endcode
1227          *
1228          * @return String Base name
1229          */
1230         public function getBaseText() {
1231                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1232                         return $this->getText();
1233                 }
1234
1235                 $parts = explode( '/', $this->getText() );
1236                 # Don't discard the real title if there's no subpage involved
1237                 if ( count( $parts ) > 1 ) {
1238                         unset( $parts[count( $parts ) - 1] );
1239                 }
1240                 return implode( '/', $parts );
1241         }
1242
1243         /**
1244          * Get the base page name title, i.e. the part before the subpage name
1245          *
1246          * @par Example:
1247          * @code
1248          * Title::newFromText('User:Foo/Bar/Baz')->getBaseTitle();
1249          * # returns: Title{User:Foo/Bar}
1250          * @endcode
1251          *
1252          * @return Title Base title
1253          * @since 1.20
1254          */
1255         public function getBaseTitle() {
1256                 return Title::makeTitle( $this->getNamespace(), $this->getBaseText() );
1257         }
1258
1259         /**
1260          * Get the lowest-level subpage name, i.e. the rightmost part after any slashes
1261          *
1262          * @par Example:
1263          * @code
1264          * Title::newFromText('User:Foo/Bar/Baz')->getSubpageText();
1265          * # returns: "Baz"
1266          * @endcode
1267          *
1268          * @return String Subpage name
1269          */
1270         public function getSubpageText() {
1271                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1272                         return( $this->mTextform );
1273                 }
1274                 $parts = explode( '/', $this->mTextform );
1275                 return( $parts[count( $parts ) - 1] );
1276         }
1277
1278         /**
1279          * Get the title for a subpage of the current page
1280          *
1281          * @par Example:
1282          * @code
1283          * Title::newFromText('User:Foo/Bar/Baz')->getSubpage("Asdf");
1284          * # returns: Title{User:Foo/Bar/Baz/Asdf}
1285          * @endcode
1286          *
1287          * @param string $text The subpage name to add to the title
1288          * @return Title Subpage title
1289          * @since 1.20
1290          */
1291         public function getSubpage( $text ) {
1292                 return Title::makeTitleSafe( $this->getNamespace(), $this->getText() . '/' . $text );
1293         }
1294
1295         /**
1296          * Get the HTML-escaped displayable text form.
1297          * Used for the title field in <a> tags.
1298          *
1299          * @return String the text, including any prefixes
1300          * @deprecated since 1.19
1301          */
1302         public function getEscapedText() {
1303                 wfDeprecated( __METHOD__, '1.19' );
1304                 return htmlspecialchars( $this->getPrefixedText() );
1305         }
1306
1307         /**
1308          * Get a URL-encoded form of the subpage text
1309          *
1310          * @return String URL-encoded subpage name
1311          */
1312         public function getSubpageUrlForm() {
1313                 $text = $this->getSubpageText();
1314                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
1315                 return( $text );
1316         }
1317
1318         /**
1319          * Get a URL-encoded title (not an actual URL) including interwiki
1320          *
1321          * @return String the URL-encoded form
1322          */
1323         public function getPrefixedURL() {
1324                 $s = $this->prefix( $this->mDbkeyform );
1325                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
1326                 return $s;
1327         }
1328
1329         /**
1330          * Helper to fix up the get{Canonical,Full,Link,Local,Internal}URL args
1331          * get{Canonical,Full,Link,Local,Internal}URL methods accepted an optional
1332          * second argument named variant. This was deprecated in favor
1333          * of passing an array of option with a "variant" key
1334          * Once $query2 is removed for good, this helper can be dropped
1335          * and the wfArrayToCgi moved to getLocalURL();
1336          *
1337          * @since 1.19 (r105919)
1338          * @param $query
1339          * @param $query2 bool
1340          * @return String
1341          */
1342         private static function fixUrlQueryArgs( $query, $query2 = false ) {
1343                 if( $query2 !== false ) {
1344                         wfDeprecated( "Title::get{Canonical,Full,Link,Local,Internal}URL " .
1345                                 "method called with a second parameter is deprecated. Add your " .
1346                                 "parameter to an array passed as the first parameter.", "1.19" );
1347                 }
1348                 if ( is_array( $query ) ) {
1349                         $query = wfArrayToCgi( $query );
1350                 }
1351                 if ( $query2 ) {
1352                         if ( is_string( $query2 ) ) {
1353                                 // $query2 is a string, we will consider this to be
1354                                 // a deprecated $variant argument and add it to the query
1355                                 $query2 = wfArrayToCgi( array( 'variant' => $query2 ) );
1356                         } else {
1357                                 $query2 = wfArrayToCgi( $query2 );
1358                         }
1359                         // If we have $query content add a & to it first
1360                         if ( $query ) {
1361                                 $query .= '&';
1362                         }
1363                         // Now append the queries together
1364                         $query .= $query2;
1365                 }
1366                 return $query;
1367         }
1368
1369         /**
1370          * Get a real URL referring to this title, with interwiki link and
1371          * fragment
1372          *
1373          * See getLocalURL for the arguments.
1374          *
1375          * @see self::getLocalURL
1376          * @see wfExpandUrl
1377          * @param $query
1378          * @param $query2 bool
1379          * @param $proto Protocol type to use in URL
1380          * @return String the URL
1381          */
1382         public function getFullURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1383                 $query = self::fixUrlQueryArgs( $query, $query2 );
1384
1385                 # Hand off all the decisions on urls to getLocalURL
1386                 $url = $this->getLocalURL( $query );
1387
1388                 # Expand the url to make it a full url. Note that getLocalURL has the
1389                 # potential to output full urls for a variety of reasons, so we use
1390                 # wfExpandUrl instead of simply prepending $wgServer
1391                 $url = wfExpandUrl( $url, $proto );
1392
1393                 # Finally, add the fragment.
1394                 $url .= $this->getFragmentForURL();
1395
1396                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
1397                 return $url;
1398         }
1399
1400         /**
1401          * Get a URL with no fragment or server name.  If this page is generated
1402          * with action=render, $wgServer is prepended.
1403          *
1404          * @param string|array $query an optional query string,
1405          *   not used for interwiki links. Can be specified as an associative array as well,
1406          *   e.g., array( 'action' => 'edit' ) (keys and values will be URL-escaped).
1407          *   Some query patterns will trigger various shorturl path replacements.
1408          * @param $query2 Mixed: An optional secondary query array. This one MUST
1409          *   be an array. If a string is passed it will be interpreted as a deprecated
1410          *   variant argument and urlencoded into a variant= argument.
1411          *   This second query argument will be added to the $query
1412          *   The second parameter is deprecated since 1.19. Pass it as a key,value
1413          *   pair in the first parameter array instead.
1414          *
1415          * @return String the URL
1416          */
1417         public function getLocalURL( $query = '', $query2 = false ) {
1418                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
1419
1420                 $query = self::fixUrlQueryArgs( $query, $query2 );
1421
1422                 $interwiki = Interwiki::fetch( $this->mInterwiki );
1423                 if ( $interwiki ) {
1424                         $namespace = $this->getNsText();
1425                         if ( $namespace != '' ) {
1426                                 # Can this actually happen? Interwikis shouldn't be parsed.
1427                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
1428                                 $namespace .= ':';
1429                         }
1430                         $url = $interwiki->getURL( $namespace . $this->getDBkey() );
1431                         $url = wfAppendQuery( $url, $query );
1432                 } else {
1433                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
1434                         if ( $query == '' ) {
1435                                 $url = str_replace( '$1', $dbkey, $wgArticlePath );
1436                                 wfRunHooks( 'GetLocalURL::Article', array( &$this, &$url ) );
1437                         } else {
1438                                 global $wgVariantArticlePath, $wgActionPaths;
1439                                 $url = false;
1440                                 $matches = array();
1441
1442                                 if ( !empty( $wgActionPaths ) &&
1443                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
1444                                 {
1445                                         $action = urldecode( $matches[2] );
1446                                         if ( isset( $wgActionPaths[$action] ) ) {
1447                                                 $query = $matches[1];
1448                                                 if ( isset( $matches[4] ) ) {
1449                                                         $query .= $matches[4];
1450                                                 }
1451                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
1452                                                 if ( $query != '' ) {
1453                                                         $url = wfAppendQuery( $url, $query );
1454                                                 }
1455                                         }
1456                                 }
1457
1458                                 if ( $url === false &&
1459                                         $wgVariantArticlePath &&
1460                                         $this->getPageLanguage()->hasVariants() &&
1461                                         preg_match( '/^variant=([^&]*)$/', $query, $matches ) )
1462                                 {
1463                                         $variant = urldecode( $matches[1] );
1464                                         if ( $this->getPageLanguage()->hasVariant( $variant ) ) {
1465                                                 // Only do the variant replacement if the given variant is a valid
1466                                                 // variant for the page's language.
1467                                                 $url = str_replace( '$2', urlencode( $variant ), $wgVariantArticlePath );
1468                                                 $url = str_replace( '$1', $dbkey, $url );
1469                                         }
1470                                 }
1471
1472                                 if ( $url === false ) {
1473                                         if ( $query == '-' ) {
1474                                                 $query = '';
1475                                         }
1476                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
1477                                 }
1478                         }
1479
1480                         wfRunHooks( 'GetLocalURL::Internal', array( &$this, &$url, $query ) );
1481
1482                         // @todo FIXME: This causes breakage in various places when we
1483                         // actually expected a local URL and end up with dupe prefixes.
1484                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
1485                                 $url = $wgServer . $url;
1486                         }
1487                 }
1488                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
1489                 return $url;
1490         }
1491
1492         /**
1493          * Get a URL that's the simplest URL that will be valid to link, locally,
1494          * to the current Title.  It includes the fragment, but does not include
1495          * the server unless action=render is used (or the link is external).  If
1496          * there's a fragment but the prefixed text is empty, we just return a link
1497          * to the fragment.
1498          *
1499          * The result obviously should not be URL-escaped, but does need to be
1500          * HTML-escaped if it's being output in HTML.
1501          *
1502          * See getLocalURL for the arguments.
1503          *
1504          * @param $query
1505          * @param $query2 bool
1506          * @param $proto Protocol to use; setting this will cause a full URL to be used
1507          * @see self::getLocalURL
1508          * @return String the URL
1509          */
1510         public function getLinkURL( $query = '', $query2 = false, $proto = PROTO_RELATIVE ) {
1511                 wfProfileIn( __METHOD__ );
1512                 if ( $this->isExternal() || $proto !== PROTO_RELATIVE ) {
1513                         $ret = $this->getFullURL( $query, $query2, $proto );
1514                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
1515                         $ret = $this->getFragmentForURL();
1516                 } else {
1517                         $ret = $this->getLocalURL( $query, $query2 ) . $this->getFragmentForURL();
1518                 }
1519                 wfProfileOut( __METHOD__ );
1520                 return $ret;
1521         }
1522
1523         /**
1524          * Get an HTML-escaped version of the URL form, suitable for
1525          * using in a link, without a server name or fragment
1526          *
1527          * See getLocalURL for the arguments.
1528          *
1529          * @see self::getLocalURL
1530          * @param $query string
1531          * @param $query2 bool|string
1532          * @return String the URL
1533          * @deprecated since 1.19
1534          */
1535         public function escapeLocalURL( $query = '', $query2 = false ) {
1536                 wfDeprecated( __METHOD__, '1.19' );
1537                 return htmlspecialchars( $this->getLocalURL( $query, $query2 ) );
1538         }
1539
1540         /**
1541          * Get an HTML-escaped version of the URL form, suitable for
1542          * using in a link, including the server name and fragment
1543          *
1544          * See getLocalURL for the arguments.
1545          *
1546          * @see self::getLocalURL
1547          * @return String the URL
1548          * @deprecated since 1.19
1549          */
1550         public function escapeFullURL( $query = '', $query2 = false ) {
1551                 wfDeprecated( __METHOD__, '1.19' );
1552                 return htmlspecialchars( $this->getFullURL( $query, $query2 ) );
1553         }
1554
1555         /**
1556          * Get the URL form for an internal link.
1557          * - Used in various Squid-related code, in case we have a different
1558          * internal hostname for the server from the exposed one.
1559          *
1560          * This uses $wgInternalServer to qualify the path, or $wgServer
1561          * if $wgInternalServer is not set. If the server variable used is
1562          * protocol-relative, the URL will be expanded to http://
1563          *
1564          * See getLocalURL for the arguments.
1565          *
1566          * @see self::getLocalURL
1567          * @return String the URL
1568          */
1569         public function getInternalURL( $query = '', $query2 = false ) {
1570                 global $wgInternalServer, $wgServer;
1571                 $query = self::fixUrlQueryArgs( $query, $query2 );
1572                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1573                 $url = wfExpandUrl( $server . $this->getLocalURL( $query ), PROTO_HTTP );
1574                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1575                 return $url;
1576         }
1577
1578         /**
1579          * Get the URL for a canonical link, for use in things like IRC and
1580          * e-mail notifications. Uses $wgCanonicalServer and the
1581          * GetCanonicalURL hook.
1582          *
1583          * NOTE: Unlike getInternalURL(), the canonical URL includes the fragment
1584          *
1585          * See getLocalURL for the arguments.
1586          *
1587          * @see self::getLocalURL
1588          * @return string The URL
1589          * @since 1.18
1590          */
1591         public function getCanonicalURL( $query = '', $query2 = false ) {
1592                 $query = self::fixUrlQueryArgs( $query, $query2 );
1593                 $url = wfExpandUrl( $this->getLocalURL( $query ) . $this->getFragmentForURL(), PROTO_CANONICAL );
1594                 wfRunHooks( 'GetCanonicalURL', array( &$this, &$url, $query ) );
1595                 return $url;
1596         }
1597
1598         /**
1599          * HTML-escaped version of getCanonicalURL()
1600          *
1601          * See getLocalURL for the arguments.
1602          *
1603          * @see self::getLocalURL
1604          * @since 1.18
1605          * @return string
1606          * @deprecated since 1.19
1607          */
1608         public function escapeCanonicalURL( $query = '', $query2 = false ) {
1609                 wfDeprecated( __METHOD__, '1.19' );
1610                 return htmlspecialchars( $this->getCanonicalURL( $query, $query2 ) );
1611         }
1612
1613         /**
1614          * Get the edit URL for this Title
1615          *
1616          * @return String the URL, or a null string if this is an
1617          *  interwiki link
1618          */
1619         public function getEditURL() {
1620                 if ( $this->mInterwiki != '' ) {
1621                         return '';
1622                 }
1623                 $s = $this->getLocalURL( 'action=edit' );
1624
1625                 return $s;
1626         }
1627
1628         /**
1629          * Is $wgUser watching this page?
1630          *
1631          * @deprecated in 1.20; use User::isWatched() instead.
1632          * @return Bool
1633          */
1634         public function userIsWatching() {
1635                 global $wgUser;
1636
1637                 if ( is_null( $this->mWatched ) ) {
1638                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1639                                 $this->mWatched = false;
1640                         } else {
1641                                 $this->mWatched = $wgUser->isWatched( $this );
1642                         }
1643                 }
1644                 return $this->mWatched;
1645         }
1646
1647         /**
1648          * Can $wgUser read this page?
1649          *
1650          * @deprecated in 1.19; use userCan(), quickUserCan() or getUserPermissionsErrors() instead
1651          * @return Bool
1652          * @todo fold these checks into userCan()
1653          */
1654         public function userCanRead() {
1655                 wfDeprecated( __METHOD__, '1.19' );
1656                 return $this->userCan( 'read' );
1657         }
1658
1659         /**
1660          * Can $user perform $action on this page?
1661          * This skips potentially expensive cascading permission checks
1662          * as well as avoids expensive error formatting
1663          *
1664          * Suitable for use for nonessential UI controls in common cases, but
1665          * _not_ for functional access control.
1666          *
1667          * May provide false positives, but should never provide a false negative.
1668          *
1669          * @param string $action action that permission needs to be checked for
1670          * @param $user User to check (since 1.19); $wgUser will be used if not
1671          *              provided.
1672          * @return Bool
1673          */
1674         public function quickUserCan( $action, $user = null ) {
1675                 return $this->userCan( $action, $user, false );
1676         }
1677
1678         /**
1679          * Can $user perform $action on this page?
1680          *
1681          * @param string $action action that permission needs to be checked for
1682          * @param $user User to check (since 1.19); $wgUser will be used if not
1683          *   provided.
1684          * @param bool $doExpensiveQueries Set this to false to avoid doing
1685          *   unnecessary queries.
1686          * @return Bool
1687          */
1688         public function userCan( $action, $user = null, $doExpensiveQueries = true ) {
1689                 if ( !$user instanceof User ) {
1690                         global $wgUser;
1691                         $user = $wgUser;
1692                 }
1693                 return !count( $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries, true ) );
1694         }
1695
1696         /**
1697          * Can $user perform $action on this page?
1698          *
1699          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1700          *
1701          * @param string $action action that permission needs to be checked for
1702          * @param $user User to check
1703          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary
1704          *   queries by skipping checks for cascading protections and user blocks.
1705          * @param array $ignoreErrors of Strings Set this to a list of message keys
1706          *   whose corresponding errors may be ignored.
1707          * @return Array of arguments to wfMessage to explain permissions problems.
1708          */
1709         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1710                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1711
1712                 // Remove the errors being ignored.
1713                 foreach ( $errors as $index => $error ) {
1714                         $error_key = is_array( $error ) ? $error[0] : $error;
1715
1716                         if ( in_array( $error_key, $ignoreErrors ) ) {
1717                                 unset( $errors[$index] );
1718                         }
1719                 }
1720
1721                 return $errors;
1722         }
1723
1724         /**
1725          * Permissions checks that fail most often, and which are easiest to test.
1726          *
1727          * @param string $action the action to check
1728          * @param $user User user to check
1729          * @param array $errors list of current errors
1730          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1731          * @param $short Boolean short circuit on first error
1732          *
1733          * @return Array list of errors
1734          */
1735         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1736                 if ( $action == 'create' ) {
1737                         if (
1738                                 ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1739                                 ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) )
1740                         ) {
1741                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1742                         }
1743                 } elseif ( $action == 'move' ) {
1744                         if ( !$user->isAllowed( 'move-rootuserpages' )
1745                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1746                                 // Show user page-specific message only if the user can move other pages
1747                                 $errors[] = array( 'cant-move-user-page' );
1748                         }
1749
1750                         // Check if user is allowed to move files if it's a file
1751                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1752                                 $errors[] = array( 'movenotallowedfile' );
1753                         }
1754
1755                         if ( !$user->isAllowed( 'move' ) ) {
1756                                 // User can't move anything
1757                                 $userCanMove = User::groupHasPermission( 'user', 'move' );
1758                                 $autoconfirmedCanMove = User::groupHasPermission( 'autoconfirmed', 'move' );
1759                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1760                                         // custom message if logged-in users without any special rights can move
1761                                         $errors[] = array( 'movenologintext' );
1762                                 } else {
1763                                         $errors[] = array( 'movenotallowed' );
1764                                 }
1765                         }
1766                 } elseif ( $action == 'move-target' ) {
1767                         if ( !$user->isAllowed( 'move' ) ) {
1768                                 // User can't move anything
1769                                 $errors[] = array( 'movenotallowed' );
1770                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1771                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1772                                 // Show user page-specific message only if the user can move other pages
1773                                 $errors[] = array( 'cant-move-to-user-page' );
1774                         }
1775                 } elseif ( !$user->isAllowed( $action ) ) {
1776                         $errors[] = $this->missingPermissionError( $action, $short );
1777                 }
1778
1779                 return $errors;
1780         }
1781
1782         /**
1783          * Add the resulting error code to the errors array
1784          *
1785          * @param array $errors list of current errors
1786          * @param $result Mixed result of errors
1787          *
1788          * @return Array list of errors
1789          */
1790         private function resultToError( $errors, $result ) {
1791                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1792                         // A single array representing an error
1793                         $errors[] = $result;
1794                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1795                         // A nested array representing multiple errors
1796                         $errors = array_merge( $errors, $result );
1797                 } elseif ( $result !== '' && is_string( $result ) ) {
1798                         // A string representing a message-id
1799                         $errors[] = array( $result );
1800                 } elseif ( $result === false ) {
1801                         // a generic "We don't want them to do that"
1802                         $errors[] = array( 'badaccess-group0' );
1803                 }
1804                 return $errors;
1805         }
1806
1807         /**
1808          * Check various permission hooks
1809          *
1810          * @param string $action the action to check
1811          * @param $user User user to check
1812          * @param array $errors list of current errors
1813          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1814          * @param $short Boolean short circuit on first error
1815          *
1816          * @return Array list of errors
1817          */
1818         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1819                 // Use getUserPermissionsErrors instead
1820                 $result = '';
1821                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1822                         return $result ? array() : array( array( 'badaccess-group0' ) );
1823                 }
1824                 // Check getUserPermissionsErrors hook
1825                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1826                         $errors = $this->resultToError( $errors, $result );
1827                 }
1828                 // Check getUserPermissionsErrorsExpensive hook
1829                 if (
1830                         $doExpensiveQueries
1831                         && !( $short && count( $errors ) > 0 )
1832                         && !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) )
1833                 ) {
1834                         $errors = $this->resultToError( $errors, $result );
1835                 }
1836
1837                 return $errors;
1838         }
1839
1840         /**
1841          * Check permissions on special pages & namespaces
1842          *
1843          * @param string $action the action to check
1844          * @param $user User user to check
1845          * @param array $errors list of current errors
1846          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1847          * @param $short Boolean short circuit on first error
1848          *
1849          * @return Array list of errors
1850          */
1851         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1852                 # Only 'createaccount' can be performed on special pages,
1853                 # which don't actually exist in the DB.
1854                 if ( NS_SPECIAL == $this->mNamespace && $action !== 'createaccount' ) {
1855                         $errors[] = array( 'ns-specialprotected' );
1856                 }
1857
1858                 # Check $wgNamespaceProtection for restricted namespaces
1859                 if ( $this->isNamespaceProtected( $user ) ) {
1860                         $ns = $this->mNamespace == NS_MAIN ?
1861                                 wfMessage( 'nstab-main' )->text() : $this->getNsText();
1862                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1863                                 array( 'protectedinterface' ) : array( 'namespaceprotected', $ns );
1864                 }
1865
1866                 return $errors;
1867         }
1868
1869         /**
1870          * Check CSS/JS sub-page permissions
1871          *
1872          * @param string $action the action to check
1873          * @param $user User user to check
1874          * @param array $errors list of current errors
1875          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1876          * @param $short Boolean short circuit on first error
1877          *
1878          * @return Array list of errors
1879          */
1880         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1881                 # Protect css/js subpages of user pages
1882                 # XXX: this might be better using restrictions
1883                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1884                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1885                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1886                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1887                                 $errors[] = array( 'customcssprotected' );
1888                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1889                                 $errors[] = array( 'customjsprotected' );
1890                         }
1891                 }
1892
1893                 return $errors;
1894         }
1895
1896         /**
1897          * Check against page_restrictions table requirements on this
1898          * page. The user must possess all required rights for this
1899          * action.
1900          *
1901          * @param string $action the action to check
1902          * @param $user User user to check
1903          * @param array $errors list of current errors
1904          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1905          * @param $short Boolean short circuit on first error
1906          *
1907          * @return Array list of errors
1908          */
1909         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1910                 foreach ( $this->getRestrictions( $action ) as $right ) {
1911                         // Backwards compatibility, rewrite sysop -> protect
1912                         if ( $right == 'sysop' ) {
1913                                 $right = 'protect';
1914                         }
1915                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1916                                 // Users with 'editprotected' permission can edit protected pages
1917                                 // without cascading option turned on.
1918                                 if ( $action != 'edit' || !$user->isAllowed( 'editprotected' )
1919                                         || $this->mCascadeRestriction )
1920                                 {
1921                                         $errors[] = array( 'protectedpagetext', $right );
1922                                 }
1923                         }
1924                 }
1925
1926                 return $errors;
1927         }
1928
1929         /**
1930          * Check restrictions on cascading pages.
1931          *
1932          * @param string $action the action to check
1933          * @param $user User to check
1934          * @param array $errors list of current errors
1935          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1936          * @param $short Boolean short circuit on first error
1937          *
1938          * @return Array list of errors
1939          */
1940         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1941                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1942                         # We /could/ use the protection level on the source page, but it's
1943                         # fairly ugly as we have to establish a precedence hierarchy for pages
1944                         # included by multiple cascade-protected pages. So just restrict
1945                         # it to people with 'protect' permission, as they could remove the
1946                         # protection anyway.
1947                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1948                         # Cascading protection depends on more than this page...
1949                         # Several cascading protected pages may include this page...
1950                         # Check each cascading level
1951                         # This is only for protection restrictions, not for all actions
1952                         if ( isset( $restrictions[$action] ) ) {
1953                                 foreach ( $restrictions[$action] as $right ) {
1954                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1955                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1956                                                 $pages = '';
1957                                                 foreach ( $cascadingSources as $page )
1958                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1959                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1960                                         }
1961                                 }
1962                         }
1963                 }
1964
1965                 return $errors;
1966         }
1967
1968         /**
1969          * Check action permissions not already checked in checkQuickPermissions
1970          *
1971          * @param string $action the action to check
1972          * @param $user User to check
1973          * @param array $errors list of current errors
1974          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1975          * @param $short Boolean short circuit on first error
1976          *
1977          * @return Array list of errors
1978          */
1979         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1980                 global $wgDeleteRevisionsLimit, $wgLang;
1981
1982                 if ( $action == 'protect' ) {
1983                         if ( count( $this->getUserPermissionsErrorsInternal( 'edit', $user, $doExpensiveQueries, true ) ) ) {
1984                                 // If they can't edit, they shouldn't protect.
1985                                 $errors[] = array( 'protect-cantedit' );
1986                         }
1987                 } elseif ( $action == 'create' ) {
1988                         $title_protection = $this->getTitleProtection();
1989                         if( $title_protection ) {
1990                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1991                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1992                                 }
1993                                 if( $title_protection['pt_create_perm'] == '' ||
1994                                         !$user->isAllowed( $title_protection['pt_create_perm'] ) )
1995                                 {
1996                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1997                                 }
1998                         }
1999                 } elseif ( $action == 'move' ) {
2000                         // Check for immobile pages
2001                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2002                                 // Specific message for this case
2003                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2004                         } elseif ( !$this->isMovable() ) {
2005                                 // Less specific message for rarer cases
2006                                 $errors[] = array( 'immobile-source-page' );
2007                         }
2008                 } elseif ( $action == 'move-target' ) {
2009                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
2010                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
2011                         } elseif ( !$this->isMovable() ) {
2012                                 $errors[] = array( 'immobile-target-page' );
2013                         }
2014                 } elseif ( $action == 'delete' ) {
2015                         if ( $doExpensiveQueries && $wgDeleteRevisionsLimit
2016                                 && !$this->userCan( 'bigdelete', $user ) && $this->isBigDeletion() )
2017                         {
2018                                 $errors[] = array( 'delete-toobig', $wgLang->formatNum( $wgDeleteRevisionsLimit ) );
2019                         }
2020                 }
2021                 return $errors;
2022         }
2023
2024         /**
2025          * Check that the user isn't blocked from editing.
2026          *
2027          * @param string $action the action to check
2028          * @param $user User to check
2029          * @param array $errors list of current errors
2030          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2031          * @param $short Boolean short circuit on first error
2032          *
2033          * @return Array list of errors
2034          */
2035         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
2036                 // Account creation blocks handled at userlogin.
2037                 // Unblocking handled in SpecialUnblock
2038                 if( !$doExpensiveQueries || in_array( $action, array( 'createaccount', 'unblock' ) ) ) {
2039                         return $errors;
2040                 }
2041
2042                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
2043
2044                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() ) {
2045                         $errors[] = array( 'confirmedittext' );
2046                 }
2047
2048                 if ( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ) {
2049                         // Don't block the user from editing their own talk page unless they've been
2050                         // explicitly blocked from that too.
2051                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
2052                         $block = $user->getBlock();
2053
2054                         // This is from OutputPage::blockedPage
2055                         // Copied at r23888 by werdna
2056
2057                         $id = $user->blockedBy();
2058                         $reason = $user->blockedFor();
2059                         if ( $reason == '' ) {
2060                                 $reason = wfMessage( 'blockednoreason' )->text();
2061                         }
2062                         $ip = $user->getRequest()->getIP();
2063
2064                         if ( is_numeric( $id ) ) {
2065                                 $name = User::whoIs( $id );
2066                         } else {
2067                                 $name = $id;
2068                         }
2069
2070                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
2071                         $blockid = $block->getId();
2072                         $blockExpiry = $block->getExpiry();
2073                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $block->mTimestamp ), true );
2074                         if ( $blockExpiry == 'infinity' ) {
2075                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
2076                         } else {
2077                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
2078                         }
2079
2080                         $intended = strval( $block->getTarget() );
2081
2082                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
2083                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
2084                 }
2085
2086                 return $errors;
2087         }
2088
2089         /**
2090          * Check that the user is allowed to read this page.
2091          *
2092          * @param string $action the action to check
2093          * @param $user User to check
2094          * @param array $errors list of current errors
2095          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
2096          * @param $short Boolean short circuit on first error
2097          *
2098          * @return Array list of errors
2099          */
2100         private function checkReadPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
2101                 global $wgWhitelistRead, $wgWhitelistReadRegexp, $wgRevokePermissions;
2102                 static $useShortcut = null;
2103
2104                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
2105                 if ( is_null( $useShortcut ) ) {
2106                         $useShortcut = true;
2107                         if ( !User::groupHasPermission( '*', 'read' ) ) {
2108                                 # Not a public wiki, so no shortcut
2109                                 $useShortcut = false;
2110                         } elseif ( !empty( $wgRevokePermissions ) ) {
2111                                 /**
2112                                  * Iterate through each group with permissions being revoked (key not included since we don't care
2113                                  * what the group name is), then check if the read permission is being revoked. If it is, then
2114                                  * we don't use the shortcut below since the user might not be able to read, even though anon
2115                                  * reading is allowed.
2116                                  */
2117                                 foreach ( $wgRevokePermissions as $perms ) {
2118                                         if ( !empty( $perms['read'] ) ) {
2119                                                 # We might be removing the read right from the user, so no shortcut
2120                                                 $useShortcut = false;
2121                                                 break;
2122                                         }
2123                                 }
2124                         }
2125                 }
2126
2127                 $whitelisted = false;
2128                 if ( $useShortcut ) {
2129                         # Shortcut for public wikis, allows skipping quite a bit of code
2130                         $whitelisted = true;
2131                 } elseif ( $user->isAllowed( 'read' ) ) {
2132                         # If the user is allowed to read pages, he is allowed to read all pages
2133                         $whitelisted = true;
2134                 } elseif ( $this->isSpecial( 'Userlogin' )
2135                         || $this->isSpecial( 'ChangePassword' )
2136                         || $this->isSpecial( 'PasswordReset' )
2137                 ) {
2138                         # Always grant access to the login page.
2139                         # Even anons need to be able to log in.
2140                         $whitelisted = true;
2141                 } elseif ( is_array( $wgWhitelistRead ) && count( $wgWhitelistRead ) ) {
2142                         # Time to check the whitelist
2143                         # Only do these checks is there's something to check against
2144                         $name = $this->getPrefixedText();
2145                         $dbName = $this->getPrefixedDBkey();
2146
2147                         // Check for explicit whitelisting with and without underscores
2148                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) ) {
2149                                 $whitelisted = true;
2150                         } elseif ( $this->getNamespace() == NS_MAIN ) {
2151                                 # Old settings might have the title prefixed with
2152                                 # a colon for main-namespace pages
2153                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
2154                                         $whitelisted = true;
2155                                 }
2156                         } elseif ( $this->isSpecialPage() ) {
2157                                 # If it's a special page, ditch the subpage bit and check again
2158                                 $name = $this->getDBkey();
2159                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
2160                                 if ( $name ) {
2161                                         $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
2162                                         if ( in_array( $pure, $wgWhitelistRead, true ) ) {
2163                                                 $whitelisted = true;
2164                                         }
2165                                 }
2166                         }
2167                 }
2168
2169                 if( !$whitelisted && is_array( $wgWhitelistReadRegexp ) && !empty( $wgWhitelistReadRegexp ) ) {
2170                         $name = $this->getPrefixedText();
2171                         // Check for regex whitelisting
2172                         foreach ( $wgWhitelistReadRegexp as $listItem ) {
2173                                 if ( preg_match( $listItem, $name ) ) {
2174                                         $whitelisted = true;
2175                                         break;
2176                                 }
2177                         }
2178                 }
2179
2180                 if ( !$whitelisted ) {
2181                         # If the title is not whitelisted, give extensions a chance to do so...
2182                         wfRunHooks( 'TitleReadWhitelist', array( $this, $user, &$whitelisted ) );
2183                         if ( !$whitelisted ) {
2184                                 $errors[] = $this->missingPermissionError( $action, $short );
2185                         }
2186                 }
2187
2188                 return $errors;
2189         }
2190
2191         /**
2192          * Get a description array when the user doesn't have the right to perform
2193          * $action (i.e. when User::isAllowed() returns false)
2194          *
2195          * @param string $action the action to check
2196          * @param $short Boolean short circuit on first error
2197          * @return Array list of errors
2198          */
2199         private function missingPermissionError( $action, $short ) {
2200                 // We avoid expensive display logic for quickUserCan's and such
2201                 if ( $short ) {
2202                         return array( 'badaccess-group0' );
2203                 }
2204
2205                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
2206                         User::getGroupsWithPermission( $action ) );
2207
2208                 if ( count( $groups ) ) {
2209                         global $wgLang;
2210                         return array(
2211                                 'badaccess-groups',
2212                                 $wgLang->commaList( $groups ),
2213                                 count( $groups )
2214                         );
2215                 } else {
2216                         return array( 'badaccess-group0' );
2217                 }
2218         }
2219
2220         /**
2221          * Can $user perform $action on this page? This is an internal function,
2222          * which checks ONLY that previously checked by userCan (i.e. it leaves out
2223          * checks on wfReadOnly() and blocks)
2224          *
2225          * @param string $action action that permission needs to be checked for
2226          * @param $user User to check
2227          * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
2228          * @param bool $short Set this to true to stop after the first permission error.
2229          * @return Array of arrays of the arguments to wfMessage to explain permissions problems.
2230          */
2231         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
2232                 wfProfileIn( __METHOD__ );
2233
2234                 # Read has special handling
2235                 if ( $action == 'read' ) {
2236                         $checks = array(
2237                                 'checkPermissionHooks',
2238                                 'checkReadPermissions',
2239                         );
2240                 } else {
2241                         $checks = array(
2242                                 'checkQuickPermissions',
2243                                 'checkPermissionHooks',
2244                                 'checkSpecialsAndNSPermissions',
2245                                 'checkCSSandJSPermissions',
2246                                 'checkPageRestrictions',
2247                                 'checkCascadingSourcesRestrictions',
2248                                 'checkActionPermissions',
2249                                 'checkUserBlock'
2250                         );
2251                 }
2252
2253                 $errors = array();
2254                 while( count( $checks ) > 0 &&
2255                                 !( $short && count( $errors ) > 0 ) ) {
2256                         $method = array_shift( $checks );
2257                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
2258                 }
2259
2260                 wfProfileOut( __METHOD__ );
2261                 return $errors;
2262         }
2263
2264         /**
2265          * Protect css subpages of user pages: can $wgUser edit
2266          * this page?
2267          *
2268          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2269          * @return Bool
2270          */
2271         public function userCanEditCssSubpage() {
2272                 global $wgUser;
2273                 wfDeprecated( __METHOD__, '1.19' );
2274                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2275                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2276         }
2277
2278         /**
2279          * Protect js subpages of user pages: can $wgUser edit
2280          * this page?
2281          *
2282          * @deprecated in 1.19; will be removed in 1.20. Use getUserPermissionsErrors() instead.
2283          * @return Bool
2284          */
2285         public function userCanEditJsSubpage() {
2286                 global $wgUser;
2287                 wfDeprecated( __METHOD__, '1.19' );
2288                 return (
2289                         ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2290                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform )
2291                 );
2292         }
2293
2294         /**
2295          * Get a filtered list of all restriction types supported by this wiki.
2296          * @param bool $exists True to get all restriction types that apply to
2297          * titles that do exist, False for all restriction types that apply to
2298          * titles that do not exist
2299          * @return array
2300          */
2301         public static function getFilteredRestrictionTypes( $exists = true ) {
2302                 global $wgRestrictionTypes;
2303                 $types = $wgRestrictionTypes;
2304                 if ( $exists ) {
2305                         # Remove the create restriction for existing titles
2306                         $types = array_diff( $types, array( 'create' ) );
2307                 } else {
2308                         # Only the create and upload restrictions apply to non-existing titles
2309                         $types = array_intersect( $types, array( 'create', 'upload' ) );
2310                 }
2311                 return $types;
2312         }
2313
2314         /**
2315          * Returns restriction types for the current Title
2316          *
2317          * @return array applicable restriction types
2318          */
2319         public function getRestrictionTypes() {
2320                 if ( $this->isSpecialPage() ) {
2321                         return array();
2322                 }
2323
2324                 $types = self::getFilteredRestrictionTypes( $this->exists() );
2325
2326                 if ( $this->getNamespace() != NS_FILE ) {
2327                         # Remove the upload restriction for non-file titles
2328                         $types = array_diff( $types, array( 'upload' ) );
2329                 }
2330
2331                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
2332
2333                 wfDebug( __METHOD__ . ': applicable restrictions to [[' .
2334                         $this->getPrefixedText() . ']] are {' . implode( ',', $types ) . "}\n" );
2335
2336                 return $types;
2337         }
2338
2339         /**
2340          * Is this title subject to title protection?
2341          * Title protection is the one applied against creation of such title.
2342          *
2343          * @return Mixed An associative array representing any existent title
2344          *   protection, or false if there's none.
2345          */
2346         private function getTitleProtection() {
2347                 // Can't protect pages in special namespaces
2348                 if ( $this->getNamespace() < 0 ) {
2349                         return false;
2350                 }
2351
2352                 // Can't protect pages that exist.
2353                 if ( $this->exists() ) {
2354                         return false;
2355                 }
2356
2357                 if ( !isset( $this->mTitleProtection ) ) {
2358                         $dbr = wfGetDB( DB_SLAVE );
2359                         $res = $dbr->select(
2360                                 'protected_titles',
2361                                 array( 'pt_user', 'pt_reason', 'pt_expiry', 'pt_create_perm' ),
2362                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2363                                 __METHOD__
2364                         );
2365
2366                         // fetchRow returns false if there are no rows.
2367                         $this->mTitleProtection = $dbr->fetchRow( $res );
2368                 }
2369                 return $this->mTitleProtection;
2370         }
2371
2372         /**
2373          * Update the title protection status
2374          *
2375          * @deprecated in 1.19; will be removed in 1.20. Use WikiPage::doUpdateRestrictions() instead.
2376          * @param $create_perm String Permission required for creation
2377          * @param string $reason Reason for protection
2378          * @param string $expiry Expiry timestamp
2379          * @return boolean true
2380          */
2381         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
2382                 wfDeprecated( __METHOD__, '1.19' );
2383
2384                 global $wgUser;
2385
2386                 $limit = array( 'create' => $create_perm );
2387                 $expiry = array( 'create' => $expiry );
2388
2389                 $page = WikiPage::factory( $this );
2390                 $cascade = false;
2391                 $status = $page->doUpdateRestrictions( $limit, $expiry, $cascade, $reason, $wgUser );
2392
2393                 return $status->isOK();
2394         }
2395
2396         /**
2397          * Remove any title protection due to page existing
2398          */
2399         public function deleteTitleProtection() {
2400                 $dbw = wfGetDB( DB_MASTER );
2401
2402                 $dbw->delete(
2403                         'protected_titles',
2404                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
2405                         __METHOD__
2406                 );
2407                 $this->mTitleProtection = false;
2408         }
2409
2410         /**
2411          * Is this page "semi-protected" - the *only* protection is autoconfirm?
2412          *
2413          * @param string $action Action to check (default: edit)
2414          * @return Bool
2415          */
2416         public function isSemiProtected( $action = 'edit' ) {
2417                 if ( $this->exists() ) {
2418                         $restrictions = $this->getRestrictions( $action );
2419                         if ( count( $restrictions ) > 0 ) {
2420                                 foreach ( $restrictions as $restriction ) {
2421                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
2422                                                 return false;
2423                                         }
2424                                 }
2425                         } else {
2426                                 # Not protected
2427                                 return false;
2428                         }
2429                         return true;
2430                 } else {
2431                         # If it doesn't exist, it can't be protected
2432                         return false;
2433                 }
2434         }
2435
2436         /**
2437          * Does the title correspond to a protected article?
2438          *
2439          * @param string $action the action the page is protected from,
2440          * by default checks all actions.
2441          * @return Bool
2442          */
2443         public function isProtected( $action = '' ) {
2444                 global $wgRestrictionLevels;
2445
2446                 $restrictionTypes = $this->getRestrictionTypes();
2447
2448                 # Special pages have inherent protection
2449                 if( $this->isSpecialPage() ) {
2450                         return true;
2451                 }
2452
2453                 # Check regular protection levels
2454                 foreach ( $restrictionTypes as $type ) {
2455                         if ( $action == $type || $action == '' ) {
2456                                 $r = $this->getRestrictions( $type );
2457                                 foreach ( $wgRestrictionLevels as $level ) {
2458                                         if ( in_array( $level, $r ) && $level != '' ) {
2459                                                 return true;
2460                                         }
2461                                 }
2462                         }
2463                 }
2464
2465                 return false;
2466         }
2467
2468         /**
2469          * Determines if $user is unable to edit this page because it has been protected
2470          * by $wgNamespaceProtection.
2471          *
2472          * @param $user User object to check permissions
2473          * @return Bool
2474          */
2475         public function isNamespaceProtected( User $user ) {
2476                 global $wgNamespaceProtection;
2477
2478                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
2479                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
2480                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
2481                                         return true;
2482                                 }
2483                         }
2484                 }
2485                 return false;
2486         }
2487
2488         /**
2489          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2490          *
2491          * @return Bool If the page is subject to cascading restrictions.
2492          */
2493         public function isCascadeProtected() {
2494                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2495                 return ( $sources > 0 );
2496         }
2497
2498         /**
2499          * Cascading protection: Get the source of any cascading restrictions on this page.
2500          *
2501          * @param bool $getPages Whether or not to retrieve the actual pages
2502          *        that the restrictions have come from.
2503          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2504          *     have come, false for none, or true if such restrictions exist, but $getPages
2505          *     was not set.  The restriction array is an array of each type, each of which
2506          *     contains a array of unique groups.
2507          */
2508         public function getCascadeProtectionSources( $getPages = true ) {
2509                 global $wgContLang;
2510                 $pagerestrictions = array();
2511
2512                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2513                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2514                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2515                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2516                 }
2517
2518                 wfProfileIn( __METHOD__ );
2519
2520                 $dbr = wfGetDB( DB_SLAVE );
2521
2522                 if ( $this->getNamespace() == NS_FILE ) {
2523                         $tables = array( 'imagelinks', 'page_restrictions' );
2524                         $where_clauses = array(
2525                                 'il_to' => $this->getDBkey(),
2526                                 'il_from=pr_page',
2527                                 'pr_cascade' => 1
2528                         );
2529                 } else {
2530                         $tables = array( 'templatelinks', 'page_restrictions' );
2531                         $where_clauses = array(
2532                                 'tl_namespace' => $this->getNamespace(),
2533                                 'tl_title' => $this->getDBkey(),
2534                                 'tl_from=pr_page',
2535                                 'pr_cascade' => 1
2536                         );
2537                 }
2538
2539                 if ( $getPages ) {
2540                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2541                                 'pr_expiry', 'pr_type', 'pr_level' );
2542                         $where_clauses[] = 'page_id=pr_page';
2543                         $tables[] = 'page';
2544                 } else {
2545                         $cols = array( 'pr_expiry' );
2546                 }
2547
2548                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2549
2550                 $sources = $getPages ? array() : false;
2551                 $now = wfTimestampNow();
2552                 $purgeExpired = false;
2553
2554                 foreach ( $res as $row ) {
2555                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2556                         if ( $expiry > $now ) {
2557                                 if ( $getPages ) {
2558                                         $page_id = $row->pr_page;
2559                                         $page_ns = $row->page_namespace;
2560                                         $page_title = $row->page_title;
2561                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2562                                         # Add groups needed for each restriction type if its not already there
2563                                         # Make sure this restriction type still exists
2564
2565                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2566                                                 $pagerestrictions[$row->pr_type] = array();
2567                                         }
2568
2569                                         if (
2570                                                 isset( $pagerestrictions[$row->pr_type] )
2571                                                 && !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] )
2572                                         ) {
2573                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2574                                         }
2575                                 } else {
2576                                         $sources = true;
2577                                 }
2578                         } else {
2579                                 // Trigger lazy purge of expired restrictions from the db
2580                                 $purgeExpired = true;
2581                         }
2582                 }
2583                 if ( $purgeExpired ) {
2584                         Title::purgeExpiredRestrictions();
2585                 }
2586
2587                 if ( $getPages ) {
2588                         $this->mCascadeSources = $sources;
2589                         $this->mCascadingRestrictions = $pagerestrictions;
2590                 } else {
2591                         $this->mHasCascadingRestrictions = $sources;
2592                 }
2593
2594                 wfProfileOut( __METHOD__ );
2595                 return array( $sources, $pagerestrictions );
2596         }
2597
2598         /**
2599          * Accessor/initialisation for mRestrictions
2600          *
2601          * @param string $action action that permission needs to be checked for
2602          * @return Array of Strings the array of groups allowed to edit this article
2603          */
2604         public function getRestrictions( $action ) {
2605                 if ( !$this->mRestrictionsLoaded ) {
2606                         $this->loadRestrictions();
2607                 }
2608                 return isset( $this->mRestrictions[$action] )
2609                                 ? $this->mRestrictions[$action]
2610                                 : array();
2611         }
2612
2613         /**
2614          * Get the expiry time for the restriction against a given action
2615          *
2616          * @param $action
2617          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2618          *     or not protected at all, or false if the action is not recognised.
2619          */
2620         public function getRestrictionExpiry( $action ) {
2621                 if ( !$this->mRestrictionsLoaded ) {
2622                         $this->loadRestrictions();
2623                 }
2624                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2625         }
2626
2627         /**
2628          * Returns cascading restrictions for the current article
2629          *
2630          * @return Boolean
2631          */
2632         function areRestrictionsCascading() {
2633                 if ( !$this->mRestrictionsLoaded ) {
2634                         $this->loadRestrictions();
2635                 }
2636
2637                 return $this->mCascadeRestriction;
2638         }
2639
2640         /**
2641          * Loads a string into mRestrictions array
2642          *
2643          * @param $res Resource restrictions as an SQL result.
2644          * @param string $oldFashionedRestrictions comma-separated list of page
2645          *        restrictions from page table (pre 1.10)
2646          */
2647         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2648                 $rows = array();
2649
2650                 foreach ( $res as $row ) {
2651                         $rows[] = $row;
2652                 }
2653
2654                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2655         }
2656
2657         /**
2658          * Compiles list of active page restrictions from both page table (pre 1.10)
2659          * and page_restrictions table for this existing page.
2660          * Public for usage by LiquidThreads.
2661          *
2662          * @param array $rows of db result objects
2663          * @param string $oldFashionedRestrictions comma-separated list of page
2664          *        restrictions from page table (pre 1.10)
2665          */
2666         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2667                 global $wgContLang;
2668                 $dbr = wfGetDB( DB_SLAVE );
2669
2670                 $restrictionTypes = $this->getRestrictionTypes();
2671
2672                 foreach ( $restrictionTypes as $type ) {
2673                         $this->mRestrictions[$type] = array();
2674                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2675                 }
2676
2677                 $this->mCascadeRestriction = false;
2678
2679                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2680
2681                 if ( $oldFashionedRestrictions === null ) {
2682                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2683                                 array( 'page_id' => $this->getArticleID() ), __METHOD__ );
2684                 }
2685
2686                 if ( $oldFashionedRestrictions != '' ) {
2687
2688                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2689                                 $temp = explode( '=', trim( $restrict ) );
2690                                 if ( count( $temp ) == 1 ) {
2691                                         // old old format should be treated as edit/move restriction
2692                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2693                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2694                                 } else {
2695                                         $restriction = trim( $temp[1] );
2696                                         if( $restriction != '' ) { //some old entries are empty
2697                                                 $this->mRestrictions[$temp[0]] = explode( ',', $restriction );
2698                                         }
2699                                 }
2700                         }
2701
2702                         $this->mOldRestrictions = true;
2703
2704                 }
2705
2706                 if ( count( $rows ) ) {
2707                         # Current system - load second to make them override.
2708                         $now = wfTimestampNow();
2709                         $purgeExpired = false;
2710
2711                         # Cycle through all the restrictions.
2712                         foreach ( $rows as $row ) {
2713
2714                                 // Don't take care of restrictions types that aren't allowed
2715                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2716                                         continue;
2717
2718                                 // This code should be refactored, now that it's being used more generally,
2719                                 // But I don't really see any harm in leaving it in Block for now -werdna
2720                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2721
2722                                 // Only apply the restrictions if they haven't expired!
2723                                 if ( !$expiry || $expiry > $now ) {
2724                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2725                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2726
2727                                         $this->mCascadeRestriction |= $row->pr_cascade;
2728                                 } else {
2729                                         // Trigger a lazy purge of expired restrictions
2730                                         $purgeExpired = true;
2731                                 }
2732                         }
2733
2734                         if ( $purgeExpired ) {
2735                                 Title::purgeExpiredRestrictions();
2736                         }
2737                 }
2738
2739                 $this->mRestrictionsLoaded = true;
2740         }
2741
2742         /**
2743          * Load restrictions from the page_restrictions table
2744          *
2745          * @param string $oldFashionedRestrictions comma-separated list of page
2746          *        restrictions from page table (pre 1.10)
2747          */
2748         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2749                 global $wgContLang;
2750                 if ( !$this->mRestrictionsLoaded ) {
2751                         if ( $this->exists() ) {
2752                                 $dbr = wfGetDB( DB_SLAVE );
2753
2754                                 $res = $dbr->select(
2755                                         'page_restrictions',
2756                                         array( 'pr_type', 'pr_expiry', 'pr_level', 'pr_cascade' ),
2757                                         array( 'pr_page' => $this->getArticleID() ),
2758                                         __METHOD__
2759                                 );
2760
2761                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2762                         } else {
2763                                 $title_protection = $this->getTitleProtection();
2764
2765                                 if ( $title_protection ) {
2766                                         $now = wfTimestampNow();
2767                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2768
2769                                         if ( !$expiry || $expiry > $now ) {
2770                                                 // Apply the restrictions
2771                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2772                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2773                                         } else { // Get rid of the old restrictions
2774                                                 Title::purgeExpiredRestrictions();
2775                                                 $this->mTitleProtection = false;
2776                                         }
2777                                 } else {
2778                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2779                                 }
2780                                 $this->mRestrictionsLoaded = true;
2781                         }
2782                 }
2783         }
2784
2785         /**
2786          * Flush the protection cache in this object and force reload from the database.
2787          * This is used when updating protection from WikiPage::doUpdateRestrictions().
2788          */
2789         public function flushRestrictions() {
2790                 $this->mRestrictionsLoaded = false;
2791                 $this->mTitleProtection = null;
2792         }
2793
2794         /**
2795          * Purge expired restrictions from the page_restrictions table
2796          */
2797         static function purgeExpiredRestrictions() {
2798                 if ( wfReadOnly() ) {
2799                         return;
2800                 }
2801
2802                 $dbw = wfGetDB( DB_MASTER );
2803                 $dbw->delete(
2804                         'page_restrictions',
2805                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2806                         __METHOD__
2807                 );
2808
2809                 $dbw->delete(
2810                         'protected_titles',
2811                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2812                         __METHOD__
2813                 );
2814         }
2815
2816         /**
2817          * Does this have subpages?  (Warning, usually requires an extra DB query.)
2818          *
2819          * @return Bool
2820          */
2821         public function hasSubpages() {
2822                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
2823                         # Duh
2824                         return false;
2825                 }
2826
2827                 # We dynamically add a member variable for the purpose of this method
2828                 # alone to cache the result.  There's no point in having it hanging
2829                 # around uninitialized in every Title object; therefore we only add it
2830                 # if needed and don't declare it statically.
2831                 if ( isset( $this->mHasSubpages ) ) {
2832                         return $this->mHasSubpages;
2833                 }
2834
2835                 $subpages = $this->getSubpages( 1 );
2836                 if ( $subpages instanceof TitleArray ) {
2837                         return $this->mHasSubpages = (bool)$subpages->count();
2838                 }
2839                 return $this->mHasSubpages = false;
2840         }
2841
2842         /**
2843          * Get all subpages of this page.
2844          *
2845          * @param int $limit maximum number of subpages to fetch; -1 for no limit
2846          * @return mixed TitleArray, or empty array if this page's namespace
2847          *  doesn't allow subpages
2848          */
2849         public function getSubpages( $limit = -1 ) {
2850                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
2851                         return array();
2852                 }
2853
2854                 $dbr = wfGetDB( DB_SLAVE );
2855                 $conds['page_namespace'] = $this->getNamespace();
2856                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
2857                 $options = array();
2858                 if ( $limit > -1 ) {
2859                         $options['LIMIT'] = $limit;
2860                 }
2861                 return $this->mSubpages = TitleArray::newFromResult(
2862                         $dbr->select( 'page',
2863                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
2864                                 $conds,
2865                                 __METHOD__,
2866                                 $options
2867                         )
2868                 );
2869         }
2870
2871         /**
2872          * Is there a version of this page in the deletion archive?
2873          *
2874          * @return Int the number of archived revisions
2875          */
2876         public function isDeleted() {
2877                 if ( $this->getNamespace() < 0 ) {
2878                         $n = 0;
2879                 } else {
2880                         $dbr = wfGetDB( DB_SLAVE );
2881
2882                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2883                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2884                                 __METHOD__
2885                         );
2886                         if ( $this->getNamespace() == NS_FILE ) {
2887                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2888                                         array( 'fa_name' => $this->getDBkey() ),
2889                                         __METHOD__
2890                                 );
2891                         }
2892                 }
2893                 return (int)$n;
2894         }
2895
2896         /**
2897          * Is there a version of this page in the deletion archive?
2898          *
2899          * @return Boolean
2900          */
2901         public function isDeletedQuick() {
2902                 if ( $this->getNamespace() < 0 ) {
2903                         return false;
2904                 }
2905                 $dbr = wfGetDB( DB_SLAVE );
2906                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2907                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2908                         __METHOD__
2909                 );
2910                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2911                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2912                                 array( 'fa_name' => $this->getDBkey() ),
2913                                 __METHOD__
2914                         );
2915                 }
2916                 return $deleted;
2917         }
2918
2919         /**
2920          * Get the article ID for this Title from the link cache,
2921          * adding it if necessary
2922          *
2923          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select
2924          *  for update
2925          * @return Int the ID
2926          */
2927         public function getArticleID( $flags = 0 ) {
2928                 if ( $this->getNamespace() < 0 ) {
2929                         return $this->mArticleID = 0;
2930                 }
2931                 $linkCache = LinkCache::singleton();
2932                 if ( $flags & self::GAID_FOR_UPDATE ) {
2933                         $oldUpdate = $linkCache->forUpdate( true );
2934                         $linkCache->clearLink( $this );
2935                         $this->mArticleID = $linkCache->addLinkObj( $this );
2936                         $linkCache->forUpdate( $oldUpdate );
2937                 } else {
2938                         if ( -1 == $this->mArticleID ) {
2939                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2940                         }
2941                 }
2942                 return $this->mArticleID;
2943         }
2944
2945         /**
2946          * Is this an article that is a redirect page?
2947          * Uses link cache, adding it if necessary
2948          *
2949          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
2950          * @return Bool
2951          */
2952         public function isRedirect( $flags = 0 ) {
2953                 if ( !is_null( $this->mRedirect ) ) {
2954                         return $this->mRedirect;
2955                 }
2956                 # Calling getArticleID() loads the field from cache as needed
2957                 if ( !$this->getArticleID( $flags ) ) {
2958                         return $this->mRedirect = false;
2959                 }
2960
2961                 $linkCache = LinkCache::singleton();
2962                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2963                 if ( $cached === null ) {
2964                         // TODO: check the assumption that the cache actually knows about this title
2965                         // and handle this, such as get the title from the database.
2966                         // See https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2967                         wfDebug( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2968                         wfDebug( wfBacktrace() );
2969                 }
2970
2971                 $this->mRedirect = (bool)$cached;
2972
2973                 return $this->mRedirect;
2974         }
2975
2976         /**
2977          * What is the length of this page?
2978          * Uses link cache, adding it if necessary
2979          *
2980          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
2981          * @return Int
2982          */
2983         public function getLength( $flags = 0 ) {
2984                 if ( $this->mLength != -1 ) {
2985                         return $this->mLength;
2986                 }
2987                 # Calling getArticleID() loads the field from cache as needed
2988                 if ( !$this->getArticleID( $flags ) ) {
2989                         return $this->mLength = 0;
2990                 }
2991                 $linkCache = LinkCache::singleton();
2992                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'length' );
2993                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
2994                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
2995                         #      as a stop gap, perhaps log this, but don't throw an exception?
2996                         wfDebug( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
2997                         wfDebug( wfBacktrace() );
2998                 }
2999
3000                 $this->mLength = intval( $cached );
3001
3002                 return $this->mLength;
3003         }
3004
3005         /**
3006          * What is the page_latest field for this page?
3007          *
3008          * @param int $flags a bit field; may be Title::GAID_FOR_UPDATE to select for update
3009          * @throws MWException
3010          * @return Int or 0 if the page doesn't exist
3011          */
3012         public function getLatestRevID( $flags = 0 ) {
3013                 if ( !( $flags & Title::GAID_FOR_UPDATE ) && $this->mLatestID !== false ) {
3014                         return intval( $this->mLatestID );
3015                 }
3016                 # Calling getArticleID() loads the field from cache as needed
3017                 if ( !$this->getArticleID( $flags ) ) {
3018                         return $this->mLatestID = 0;
3019                 }
3020                 $linkCache = LinkCache::singleton();
3021                 $linkCache->addLinkObj( $this );
3022                 $cached = $linkCache->getGoodLinkFieldObj( $this, 'revision' );
3023                 if ( $cached === null ) { # check the assumption that the cache actually knows about this title
3024                         # XXX: this does apparently happen, see https://bugzilla.wikimedia.org/show_bug.cgi?id=37209
3025                         #      as a stop gap, perhaps log this, but don't throw an exception?
3026                         throw new MWException( "LinkCache doesn't currently know about this title: " . $this->getPrefixedDBkey() );
3027                 }
3028
3029                 $this->mLatestID = intval( $cached );
3030
3031                 return $this->mLatestID;
3032         }
3033
3034         /**
3035          * This clears some fields in this object, and clears any associated
3036          * keys in the "bad links" section of the link cache.
3037          *
3038          * - This is called from WikiPage::doEdit() and WikiPage::insertOn() to allow
3039          * loading of the new page_id. It's also called from
3040          * WikiPage::doDeleteArticleReal()
3041          *
3042          * @param int $newid the new Article ID
3043          */
3044         public function resetArticleID( $newid ) {
3045                 $linkCache = LinkCache::singleton();
3046                 $linkCache->clearLink( $this );
3047
3048                 if ( $newid === false ) {
3049                         $this->mArticleID = -1;
3050                 } else {
3051                         $this->mArticleID = intval( $newid );
3052                 }
3053                 $this->mRestrictionsLoaded = false;
3054                 $this->mRestrictions = array();
3055                 $this->mRedirect = null;
3056                 $this->mLength = -1;
3057                 $this->mLatestID = false;
3058                 $this->mContentModel = false;
3059                 $this->mEstimateRevisions = null;
3060         }
3061
3062         /**
3063          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
3064          *
3065          * @param string $text containing title to capitalize
3066          * @param int $ns namespace index, defaults to NS_MAIN
3067          * @return String containing capitalized title
3068          */
3069         public static function capitalize( $text, $ns = NS_MAIN ) {
3070                 global $wgContLang;
3071
3072                 if ( MWNamespace::isCapitalized( $ns ) ) {
3073                         return $wgContLang->ucfirst( $text );
3074                 } else {
3075                         return $text;
3076                 }
3077         }
3078
3079         /**
3080          * Secure and split - main initialisation function for this object
3081          *
3082          * Assumes that mDbkeyform has been set, and is urldecoded
3083          * and uses underscores, but not otherwise munged.  This function
3084          * removes illegal characters, splits off the interwiki and
3085          * namespace prefixes, sets the other forms, and canonicalizes
3086          * everything.
3087          *
3088          * @return Bool true on success
3089          */
3090         private function secureAndSplit() {
3091                 global $wgContLang, $wgLocalInterwiki;
3092
3093                 # Initialisation
3094                 $this->mInterwiki = $this->mFragment = '';
3095                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
3096
3097                 $dbkey = $this->mDbkeyform;
3098
3099                 # Strip Unicode bidi override characters.
3100                 # Sometimes they slip into cut-n-pasted page titles, where the
3101                 # override chars get included in list displays.
3102                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
3103
3104                 # Clean up whitespace
3105                 # Note: use of the /u option on preg_replace here will cause
3106                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
3107                 # conveniently disabling them.
3108                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
3109                 $dbkey = trim( $dbkey, '_' );
3110
3111                 if ( $dbkey == '' ) {
3112                         return false;
3113                 }
3114
3115                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
3116                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
3117                         return false;
3118                 }
3119
3120                 $this->mDbkeyform = $dbkey;
3121
3122                 # Initial colon indicates main namespace rather than specified default
3123                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
3124                 if ( ':' == $dbkey[0] ) {
3125                         $this->mNamespace = NS_MAIN;
3126                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
3127                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
3128                 }
3129
3130                 # Namespace or interwiki prefix
3131                 $firstPass = true;
3132                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
3133                 do {
3134                         $m = array();
3135                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
3136                                 $p = $m[1];
3137                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
3138                                         # Ordinary namespace
3139                                         $dbkey = $m[2];
3140                                         $this->mNamespace = $ns;
3141                                         # For Talk:X pages, check if X has a "namespace" prefix
3142                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
3143                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
3144                                                         # Disallow Talk:File:x type titles...
3145                                                         return false;
3146                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
3147                                                         # Disallow Talk:Interwiki:x type titles...
3148                                                         return false;
3149                                                 }
3150                                         }
3151                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
3152                                         if ( !$firstPass ) {
3153                                                 # Can't make a local interwiki link to an interwiki link.
3154                                                 # That's just crazy!
3155                                                 return false;
3156                                         }
3157
3158                                         # Interwiki link
3159                                         $dbkey = $m[2];
3160                                         $this->mInterwiki = $wgContLang->lc( $p );
3161
3162                                         # Redundant interwiki prefix to the local wiki
3163                                         if ( $wgLocalInterwiki !== false
3164                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
3165                                         {
3166                                                 if ( $dbkey == '' ) {
3167                                                         # Can't have an empty self-link
3168                                                         return false;
3169                                                 }
3170                                                 $this->mInterwiki = '';
3171                                                 $firstPass = false;
3172                                                 # Do another namespace split...
3173                                                 continue;
3174                                         }
3175
3176                                         # If there's an initial colon after the interwiki, that also
3177                                         # resets the default namespace
3178                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
3179                                                 $this->mNamespace = NS_MAIN;
3180                                                 $dbkey = substr( $dbkey, 1 );
3181                                         }
3182                                 }
3183                                 # If there's no recognized interwiki or namespace,
3184                                 # then let the colon expression be part of the title.
3185                         }
3186                         break;
3187                 } while ( true );
3188
3189                 # We already know that some pages won't be in the database!
3190                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
3191                         $this->mArticleID = 0;
3192                 }
3193                 $fragment = strstr( $dbkey, '#' );
3194                 if ( false !== $fragment ) {
3195                         $this->setFragment( $fragment );
3196                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
3197                         # remove whitespace again: prevents "Foo_bar_#"
3198                         # becoming "Foo_bar_"
3199                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
3200                 }
3201
3202                 # Reject illegal characters.
3203                 $rxTc = self::getTitleInvalidRegex();
3204                 if ( preg_match( $rxTc, $dbkey ) ) {
3205                         return false;
3206                 }
3207
3208                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
3209                 # reachable due to the way web browsers deal with 'relative' URLs.
3210                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
3211                 if (
3212                         strpos( $dbkey, '.' ) !== false &&
3213                         (
3214                                 $dbkey === '.' || $dbkey === '..' ||
3215                                 strpos( $dbkey, './' ) === 0 ||
3216                                 strpos( $dbkey, '../' ) === 0 ||
3217                                 strpos( $dbkey, '/./' ) !== false ||
3218                                 strpos( $dbkey, '/../' ) !== false ||
3219                                 substr( $dbkey, -2 ) == '/.' ||
3220                                 substr( $dbkey, -3 ) == '/..'
3221                         )
3222                 ) {
3223                         return false;
3224                 }
3225
3226                 # Magic tilde sequences? Nu-uh!
3227                 if ( strpos( $dbkey, '~~~' ) !== false ) {
3228                         return false;
3229                 }
3230
3231                 # Limit the size of titles to 255 bytes. This is typically the size of the
3232                 # underlying database field. We make an exception for special pages, which
3233                 # don't need to be stored in the database, and may edge over 255 bytes due
3234                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
3235                 if (
3236                         ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 )
3237                         || strlen( $dbkey ) > 512
3238                 ) {
3239                         return false;
3240                 }
3241
3242                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
3243                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
3244                 # other site might be case-sensitive.
3245                 $this->mUserCaseDBKey = $dbkey;
3246                 if ( $this->mInterwiki == '' ) {
3247                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
3248                 }
3249
3250                 # Can't make a link to a namespace alone... "empty" local links can only be
3251                 # self-links with a fragment identifier.
3252                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
3253                         return false;
3254                 }
3255
3256                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
3257                 // IP names are not allowed for accounts, and can only be referring to
3258                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
3259                 // there are numerous ways to present the same IP. Having sp:contribs scan
3260                 // them all is silly and having some show the edits and others not is
3261                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
3262                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
3263                         ? IP::sanitizeIP( $dbkey )
3264                         : $dbkey;
3265
3266                 // Any remaining initial :s are illegal.
3267                 if ( $dbkey !== '' && ':' == $dbkey[0] ) {
3268                         return false;
3269                 }
3270
3271                 # Fill fields
3272                 $this->mDbkeyform = $dbkey;
3273                 $this->mUrlform = wfUrlencode( $dbkey );
3274
3275                 $this->mTextform = str_replace( '_', ' ', $dbkey );
3276
3277                 return true;
3278         }
3279
3280         /**
3281          * Get an array of Title objects linking to this Title
3282          * Also stores the IDs in the link cache.
3283          *
3284          * WARNING: do not use this function on arbitrary user-supplied titles!
3285          * On heavily-used templates it will max out the memory.
3286          *
3287          * @param array $options may be FOR UPDATE
3288          * @param string $table table name
3289          * @param string $prefix fields prefix
3290          * @return Array of Title objects linking here
3291          */
3292         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3293                 if ( count( $options ) > 0 ) {
3294                         $db = wfGetDB( DB_MASTER );
3295                 } else {
3296                         $db = wfGetDB( DB_SLAVE );
3297                 }
3298
3299                 $res = $db->select(
3300                         array( 'page', $table ),
3301                         self::getSelectFields(),
3302                         array(
3303                                 "{$prefix}_from=page_id",
3304                                 "{$prefix}_namespace" => $this->getNamespace(),
3305                                 "{$prefix}_title"     => $this->getDBkey() ),
3306                         __METHOD__,
3307                         $options
3308                 );
3309
3310                 $retVal = array();
3311                 if ( $res->numRows() ) {
3312                         $linkCache = LinkCache::singleton();
3313                         foreach ( $res as $row ) {
3314                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
3315                                 if ( $titleObj ) {
3316                                         $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3317                                         $retVal[] = $titleObj;
3318                                 }
3319                         }
3320                 }
3321                 return $retVal;
3322         }
3323
3324         /**
3325          * Get an array of Title objects using this Title as a template
3326          * Also stores the IDs in the link cache.
3327          *
3328          * WARNING: do not use this function on arbitrary user-supplied titles!
3329          * On heavily-used templates it will max out the memory.
3330          *
3331          * @param array $options may be FOR UPDATE
3332          * @return Array of Title the Title objects linking here
3333          */
3334         public function getTemplateLinksTo( $options = array() ) {
3335                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
3336         }
3337
3338         /**
3339          * Get an array of Title objects linked from this Title
3340          * Also stores the IDs in the link cache.
3341          *
3342          * WARNING: do not use this function on arbitrary user-supplied titles!
3343          * On heavily-used templates it will max out the memory.
3344          *
3345          * @param array $options may be FOR UPDATE
3346          * @param string $table table name
3347          * @param string $prefix fields prefix
3348          * @return Array of Title objects linking here
3349          */
3350         public function getLinksFrom( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
3351                 global $wgContentHandlerUseDB;
3352
3353                 $id = $this->getArticleID();
3354
3355                 # If the page doesn't exist; there can't be any link from this page
3356                 if ( !$id ) {
3357                         return array();
3358                 }
3359
3360                 if ( count( $options ) > 0 ) {
3361                         $db = wfGetDB( DB_MASTER );
3362                 } else {
3363                         $db = wfGetDB( DB_SLAVE );
3364                 }
3365
3366                 $namespaceFiled = "{$prefix}_namespace";
3367                 $titleField = "{$prefix}_title";
3368
3369                 $fields = array( $namespaceFiled, $titleField, 'page_id', 'page_len', 'page_is_redirect', 'page_latest' );
3370                 if ( $wgContentHandlerUseDB ) $fields[] = 'page_content_model';
3371
3372                 $res = $db->select(
3373                         array( $table, 'page' ),
3374                         $fields,
3375                         array( "{$prefix}_from" => $id ),
3376                         __METHOD__,
3377                         $options,
3378                         array( 'page' => array( 'LEFT JOIN', array( "page_namespace=$namespaceFiled", "page_title=$titleField" ) ) )
3379                 );
3380
3381                 $retVal = array();
3382                 if ( $res->numRows() ) {
3383                         $linkCache = LinkCache::singleton();
3384                         foreach ( $res as $row ) {
3385                                 $titleObj = Title::makeTitle( $row->$namespaceFiled, $row->$titleField );
3386                                 if ( $titleObj ) {
3387                                         if ( $row->page_id ) {
3388                                                 $linkCache->addGoodLinkObjFromRow( $titleObj, $row );
3389                                         } else {
3390                                                 $linkCache->addBadLinkObj( $titleObj );
3391                                         }
3392                                         $retVal[] = $titleObj;
3393                                 }
3394                         }
3395                 }
3396                 return $retVal;
3397         }
3398
3399         /**
3400          * Get an array of Title objects used on this Title as a template
3401          * Also stores the IDs in the link cache.
3402          *
3403          * WARNING: do not use this function on arbitrary user-supplied titles!
3404          * On heavily-used templates it will max out the memory.
3405          *
3406          * @param array $options may be FOR UPDATE
3407          * @return Array of Title the Title objects used here
3408          */
3409         public function getTemplateLinksFrom( $options = array() ) {
3410                 return $this->getLinksFrom( $options, 'templatelinks', 'tl' );
3411         }
3412
3413         /**
3414          * Get an array of Title objects referring to non-existent articles linked from this page
3415          *
3416          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
3417          * @return Array of Title the Title objects
3418          */
3419         public function getBrokenLinksFrom() {
3420                 if ( $this->getArticleID() == 0 ) {
3421                         # All links from article ID 0 are false positives
3422                         return array();
3423                 }
3424
3425                 $dbr = wfGetDB( DB_SLAVE );
3426                 $res = $dbr->select(
3427                         array( 'page', 'pagelinks' ),
3428                         array( 'pl_namespace', 'pl_title' ),
3429                         array(
3430                                 'pl_from' => $this->getArticleID(),
3431                                 'page_namespace IS NULL'
3432                         ),
3433                         __METHOD__, array(),
3434                         array(
3435                                 'page' => array(
3436                                         'LEFT JOIN',
3437                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
3438                                 )
3439                         )
3440                 );
3441
3442                 $retVal = array();
3443                 foreach ( $res as $row ) {
3444                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
3445                 }
3446                 return $retVal;
3447         }
3448
3449         /**
3450          * Get a list of URLs to purge from the Squid cache when this
3451          * page changes
3452          *
3453          * @return Array of String the URLs
3454          */
3455         public function getSquidURLs() {
3456                 $urls = array(
3457                         $this->getInternalURL(),
3458                         $this->getInternalURL( 'action=history' )
3459                 );
3460
3461                 $pageLang = $this->getPageLanguage();
3462                 if ( $pageLang->hasVariants() ) {
3463                         $variants = $pageLang->getVariants();
3464                         foreach ( $variants as $vCode ) {
3465                                 $urls[] = $this->getInternalURL( '', $vCode );
3466                         }
3467                 }
3468
3469                 return $urls;
3470         }
3471
3472         /**
3473          * Purge all applicable Squid URLs
3474          */
3475         public function purgeSquid() {
3476                 global $wgUseSquid;
3477                 if ( $wgUseSquid ) {
3478                         $urls = $this->getSquidURLs();
3479                         $u = new SquidUpdate( $urls );
3480                         $u->doUpdate();
3481                 }
3482         }
3483
3484         /**
3485          * Move this page without authentication
3486          *
3487          * @param $nt Title the new page Title
3488          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3489          */
3490         public function moveNoAuth( &$nt ) {
3491                 return $this->moveTo( $nt, false );
3492         }
3493
3494         /**
3495          * Check whether a given move operation would be valid.
3496          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
3497          *
3498          * @param $nt Title the new title
3499          * @param bool $auth indicates whether $wgUser's permissions
3500          *  should be checked
3501          * @param string $reason is the log summary of the move, used for spam checking
3502          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
3503          */
3504         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
3505                 global $wgUser, $wgContentHandlerUseDB;
3506
3507                 $errors = array();
3508                 if ( !$nt ) {
3509                         // Normally we'd add this to $errors, but we'll get
3510                         // lots of syntax errors if $nt is not an object
3511                         return array( array( 'badtitletext' ) );
3512                 }
3513                 if ( $this->equals( $nt ) ) {
3514                         $errors[] = array( 'selfmove' );
3515                 }
3516                 if ( !$this->isMovable() ) {
3517                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
3518                 }
3519                 if ( $nt->getInterwiki() != '' ) {
3520                         $errors[] = array( 'immobile-target-namespace-iw' );
3521                 }
3522                 if ( !$nt->isMovable() ) {
3523                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
3524                 }
3525
3526                 $oldid = $this->getArticleID();
3527                 $newid = $nt->getArticleID();
3528
3529                 if ( strlen( $nt->getDBkey() ) < 1 ) {
3530                         $errors[] = array( 'articleexists' );
3531                 }
3532                 if (
3533                         ( $this->getDBkey() == '' ) ||
3534                         ( !$oldid ) ||
3535                         ( $nt->getDBkey() == '' )
3536                 ) {
3537                         $errors[] = array( 'badarticleerror' );
3538                 }
3539
3540                 // Content model checks
3541                 if ( !$wgContentHandlerUseDB &&
3542                                 $this->getContentModel() !== $nt->getContentModel() ) {
3543                         // can't move a page if that would change the page's content model
3544                         $errors[] = array(
3545                                 'bad-target-model',
3546                                 ContentHandler::getLocalizedName( $this->getContentModel() ),
3547                                 ContentHandler::getLocalizedName( $nt->getContentModel() )
3548                         );
3549                 }
3550
3551                 // Image-specific checks
3552                 if ( $this->getNamespace() == NS_FILE ) {
3553                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3554                 }
3555
3556                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3557                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3558                 }
3559
3560                 if ( $auth ) {
3561                         $errors = wfMergeErrorArrays( $errors,
3562                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3563                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3564                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3565                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3566                 }
3567
3568                 $match = EditPage::matchSummarySpamRegex( $reason );
3569                 if ( $match !== false ) {
3570                         // This is kind of lame, won't display nice
3571                         $errors[] = array( 'spamprotectiontext' );
3572                 }
3573
3574                 $err = null;
3575                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3576                         $errors[] = array( 'hookaborted', $err );
3577                 }
3578
3579                 # The move is allowed only if (1) the target doesn't exist, or
3580                 # (2) the target is a redirect to the source, and has no history
3581                 # (so we can undo bad moves right after they're done).
3582
3583                 if ( 0 != $newid ) { # Target exists; check for validity
3584                         if ( !$this->isValidMoveTarget( $nt ) ) {
3585                                 $errors[] = array( 'articleexists' );
3586                         }
3587                 } else {
3588                         $tp = $nt->getTitleProtection();
3589                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3590                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3591                                 $errors[] = array( 'cantmove-titleprotected' );
3592                         }
3593                 }
3594                 if ( empty( $errors ) ) {
3595                         return true;
3596                 }
3597                 return $errors;
3598         }
3599
3600         /**
3601          * Check if the requested move target is a valid file move target
3602          * @param Title $nt Target title
3603          * @return array List of errors
3604          */
3605         protected function validateFileMoveOperation( $nt ) {
3606                 global $wgUser;
3607
3608                 $errors = array();
3609
3610                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is not allowed until below
3611
3612                 $file = wfLocalFile( $this );
3613                 if ( $file->exists() ) {
3614                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3615                                 $errors[] = array( 'imageinvalidfilename' );
3616                         }
3617                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3618                                 $errors[] = array( 'imagetypemismatch' );
3619                         }
3620                 }
3621
3622                 if ( $nt->getNamespace() != NS_FILE ) {
3623                         $errors[] = array( 'imagenocrossnamespace' );
3624                         // From here we want to do checks on a file object, so if we can't
3625                         // create one, we must return.
3626                         return $errors;
3627                 }
3628
3629                 // wfFindFile( $nt ) / wfLocalFile( $nt ) is allowed below here
3630
3631                 $destFile = wfLocalFile( $nt );
3632                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3633                         $errors[] = array( 'file-exists-sharedrepo' );
3634                 }
3635
3636                 return $errors;
3637         }
3638
3639         /**
3640          * Move a title to a new location
3641          *
3642          * @param $nt Title the new title
3643          * @param bool $auth indicates whether $wgUser's permissions
3644          *  should be checked
3645          * @param string $reason the reason for the move
3646          * @param bool $createRedirect Whether to create a redirect from the old title to the new title.
3647          *  Ignored if the user doesn't have the suppressredirect right.
3648          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3649          */
3650         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3651                 global $wgUser;
3652                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3653                 if ( is_array( $err ) ) {
3654                         // Auto-block user's IP if the account was "hard" blocked
3655                         $wgUser->spreadAnyEditBlock();
3656                         return $err;
3657                 }
3658                 // Check suppressredirect permission
3659                 if ( $auth && !$wgUser->isAllowed( 'suppressredirect' ) ) {
3660                         $createRedirect = true;
3661                 }
3662
3663                 // If it is a file, move it first.
3664                 // It is done before all other moving stuff is done because it's hard to revert.
3665                 $dbw = wfGetDB( DB_MASTER );
3666                 if ( $this->getNamespace() == NS_FILE ) {
3667                         $file = wfLocalFile( $this );
3668                         if ( $file->exists() ) {
3669                                 $status = $file->move( $nt );
3670                                 if ( !$status->isOk() ) {
3671                                         return $status->getErrorsArray();
3672                                 }
3673                         }
3674                         // Clear RepoGroup process cache
3675                         RepoGroup::singleton()->clearCache( $this );
3676                         RepoGroup::singleton()->clearCache( $nt ); # clear false negative cache
3677                 }
3678
3679                 $dbw->begin( __METHOD__ ); # If $file was a LocalFile, its transaction would have closed our own.
3680                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3681                 $protected = $this->isProtected();
3682
3683                 // Do the actual move
3684                 $this->moveToInternal( $nt, $reason, $createRedirect );
3685
3686                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3687                 // cl_timestamp, which may disturb time-based lists on some sites.
3688                 $prefixes = $dbw->select(
3689                         'categorylinks',
3690                         array( 'cl_sortkey_prefix', 'cl_to' ),
3691                         array( 'cl_from' => $pageid ),
3692                         __METHOD__
3693                 );
3694                 foreach ( $prefixes as $prefixRow ) {
3695                         $prefix = $prefixRow->cl_sortkey_prefix;
3696                         $catTo = $prefixRow->cl_to;
3697                         $dbw->update( 'categorylinks',
3698                                 array(
3699                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3700                                                 $nt->getCategorySortkey( $prefix ) ),
3701                                         'cl_timestamp=cl_timestamp' ),
3702                                 array(
3703                                         'cl_from' => $pageid,
3704                                         'cl_to' => $catTo ),
3705                                 __METHOD__
3706                         );
3707                 }
3708
3709                 $redirid = $this->getArticleID();
3710
3711                 if ( $protected ) {
3712                         # Protect the redirect title as the title used to be...
3713                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3714                                 array(
3715                                         'pr_page'    => $redirid,
3716                                         'pr_type'    => 'pr_type',
3717                                         'pr_level'   => 'pr_level',
3718                                         'pr_cascade' => 'pr_cascade',
3719                                         'pr_user'    => 'pr_user',
3720                                         'pr_expiry'  => 'pr_expiry'
3721                                 ),
3722                                 array( 'pr_page' => $pageid ),
3723                                 __METHOD__,
3724                                 array( 'IGNORE' )
3725                         );
3726                         # Update the protection log
3727                         $log = new LogPage( 'protect' );
3728                         $comment = wfMessage(
3729                                 'prot_1movedto2',
3730                                 $this->getPrefixedText(),
3731                                 $nt->getPrefixedText()
3732                         )->inContentLanguage()->text();
3733                         if ( $reason ) {
3734                                 $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3735                         }
3736                         // @todo FIXME: $params?
3737                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3738                 }
3739
3740                 # Update watchlists
3741                 $oldnamespace = MWNamespace::getSubject( $this->getNamespace() );
3742                 $newnamespace = MWNamespace::getSubject( $nt->getNamespace() );
3743                 $oldtitle = $this->getDBkey();
3744                 $newtitle = $nt->getDBkey();
3745
3746                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3747                         WatchedItem::duplicateEntries( $this, $nt );
3748                 }
3749
3750                 $dbw->commit( __METHOD__ );
3751
3752                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3753                 return true;
3754         }
3755
3756         /**
3757          * Move page to a title which is either a redirect to the
3758          * source page or nonexistent
3759          *
3760          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3761          * @param string $reason The reason for the move
3762          * @param bool $createRedirect Whether to leave a redirect at the old title. Does not check
3763          *   if the user has the suppressredirect right
3764          * @throws MWException
3765          */
3766         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3767                 global $wgUser, $wgContLang;
3768
3769                 if ( $nt->exists() ) {
3770                         $moveOverRedirect = true;
3771                         $logType = 'move_redir';
3772                 } else {
3773                         $moveOverRedirect = false;
3774                         $logType = 'move';
3775                 }
3776
3777                 if ( $createRedirect ) {
3778                         $contentHandler = ContentHandler::getForTitle( $this );
3779                         $redirectContent = $contentHandler->makeRedirectContent( $nt );
3780
3781                         // NOTE: If this page's content model does not support redirects, $redirectContent will be null.
3782                 } else {
3783                         $redirectContent = null;
3784                 }
3785
3786                 $logEntry = new ManualLogEntry( 'move', $logType );
3787                 $logEntry->setPerformer( $wgUser );
3788                 $logEntry->setTarget( $this );
3789                 $logEntry->setComment( $reason );
3790                 $logEntry->setParameters( array(
3791                         '4::target' => $nt->getPrefixedText(),
3792                         '5::noredir' => $redirectContent ? '0': '1',
3793                 ) );
3794
3795                 $formatter = LogFormatter::newFromEntry( $logEntry );
3796                 $formatter->setContext( RequestContext::newExtraneousContext( $this ) );
3797                 $comment = $formatter->getPlainActionText();
3798                 if ( $reason ) {
3799                         $comment .= wfMessage( 'colon-separator' )->inContentLanguage()->text() . $reason;
3800                 }
3801                 # Truncate for whole multibyte characters.
3802                 $comment = $wgContLang->truncate( $comment, 255 );
3803
3804                 $oldid = $this->getArticleID();
3805
3806                 $dbw = wfGetDB( DB_MASTER );
3807
3808                 $newpage = WikiPage::factory( $nt );
3809
3810                 if ( $moveOverRedirect ) {
3811                         $newid = $nt->getArticleID();
3812
3813                         # Delete the old redirect. We don't save it to history since
3814                         # by definition if we've got here it's rather uninteresting.
3815                         # We have to remove it so that the next step doesn't trigger
3816                         # a conflict on the unique namespace+title index...
3817                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3818
3819                         $newpage->doDeleteUpdates( $newid );
3820                 }
3821
3822                 # Save a null revision in the page's history notifying of the move
3823                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3824                 if ( !is_object( $nullRevision ) ) {
3825                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3826                 }
3827
3828                 $nullRevision->insertOn( $dbw );
3829
3830                 # Change the name of the target page:
3831                 $dbw->update( 'page',
3832                         /* SET */ array(
3833                                 'page_namespace' => $nt->getNamespace(),
3834                                 'page_title'     => $nt->getDBkey(),
3835                         ),
3836                         /* WHERE */ array( 'page_id' => $oldid ),
3837                         __METHOD__
3838                 );
3839
3840                 $this->resetArticleID( 0 );
3841                 $nt->resetArticleID( $oldid );
3842                 $newpage->loadPageData( WikiPage::READ_LOCKING ); // bug 46397
3843
3844                 $newpage->updateRevisionOn( $dbw, $nullRevision );
3845
3846                 wfRunHooks( 'NewRevisionFromEditComplete',
3847                         array( $newpage, $nullRevision, $nullRevision->getParentId(), $wgUser ) );
3848
3849                 $newpage->doEditUpdates( $nullRevision, $wgUser, array( 'changed' => false ) );
3850
3851                 if ( !$moveOverRedirect ) {
3852                         WikiPage::onArticleCreate( $nt );
3853                 }
3854
3855                 # Recreate the redirect, this time in the other direction.
3856                 if ( !$redirectContent ) {
3857                         WikiPage::onArticleDelete( $this );
3858                 } else {
3859                         $redirectArticle = WikiPage::factory( $this );
3860                         $redirectArticle->loadFromRow( false, WikiPage::READ_LOCKING ); // bug 46397
3861                         $newid = $redirectArticle->insertOn( $dbw );
3862                         if ( $newid ) { // sanity
3863                                 $redirectRevision = new Revision( array(
3864                                         'title'   => $this, // for determining the default content model
3865                                         'page'    => $newid,
3866                                         'comment' => $comment,
3867                                         'content'    => $redirectContent ) );
3868                                 $redirectRevision->insertOn( $dbw );
3869                                 $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3870
3871                                 wfRunHooks( 'NewRevisionFromEditComplete',
3872                                         array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3873
3874                                 $redirectArticle->doEditUpdates( $redirectRevision, $wgUser, array( 'created' => true ) );
3875                         }
3876                 }
3877
3878                 # Log the move
3879                 $logid = $logEntry->insert();
3880                 $logEntry->publish( $logid );
3881         }
3882
3883         /**
3884          * Move this page's subpages to be subpages of $nt
3885          *
3886          * @param $nt Title Move target
3887          * @param bool $auth Whether $wgUser's permissions should be checked
3888          * @param string $reason The reason for the move
3889          * @param bool $createRedirect Whether to create redirects from the old subpages to
3890          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3891          * @return mixed array with old page titles as keys, and strings (new page titles) or
3892          *     arrays (errors) as values, or an error array with numeric indices if no pages
3893          *     were moved
3894          */
3895         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3896                 global $wgMaximumMovedPages;
3897                 // Check permissions
3898                 if ( !$this->userCan( 'move-subpages' ) ) {
3899                         return array( 'cant-move-subpages' );
3900                 }
3901                 // Do the source and target namespaces support subpages?
3902                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3903                         return array( 'namespace-nosubpages',
3904                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3905                 }
3906                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3907                         return array( 'namespace-nosubpages',
3908                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3909                 }
3910
3911                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3912                 $retval = array();
3913                 $count = 0;
3914                 foreach ( $subpages as $oldSubpage ) {
3915                         $count++;
3916                         if ( $count > $wgMaximumMovedPages ) {
3917                                 $retval[$oldSubpage->getPrefixedTitle()] =
3918                                                 array( 'movepage-max-pages',
3919                                                         $wgMaximumMovedPages );
3920                                 break;
3921                         }
3922
3923                         // We don't know whether this function was called before
3924                         // or after moving the root page, so check both
3925                         // $this and $nt
3926                         if ( $oldSubpage->getArticleID() == $this->getArticleID() ||
3927                                         $oldSubpage->getArticleID() == $nt->getArticleID() )
3928                         {
3929                                 // When moving a page to a subpage of itself,
3930                                 // don't move it twice
3931                                 continue;
3932                         }
3933                         $newPageName = preg_replace(
3934                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3935                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3936                                         $oldSubpage->getDBkey() );
3937                         if ( $oldSubpage->isTalkPage() ) {
3938                                 $newNs = $nt->getTalkPage()->getNamespace();
3939                         } else {
3940                                 $newNs = $nt->getSubjectPage()->getNamespace();
3941                         }
3942                         # Bug 14385: we need makeTitleSafe because the new page names may
3943                         # be longer than 255 characters.
3944                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3945
3946                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3947                         if ( $success === true ) {
3948                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3949                         } else {
3950                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3951                         }
3952                 }
3953                 return $retval;
3954         }
3955
3956         /**
3957          * Checks if this page is just a one-rev redirect.
3958          * Adds lock, so don't use just for light purposes.
3959          *
3960          * @return Bool
3961          */
3962         public function isSingleRevRedirect() {
3963                 global $wgContentHandlerUseDB;
3964
3965                 $dbw = wfGetDB( DB_MASTER );
3966
3967                 # Is it a redirect?
3968                 $fields = array( 'page_is_redirect', 'page_latest', 'page_id' );
3969                 if ( $wgContentHandlerUseDB ) $fields[] = 'page_content_model';
3970
3971                 $row = $dbw->selectRow( 'page',
3972                         $fields,
3973                         $this->pageCond(),
3974                         __METHOD__,
3975                         array( 'FOR UPDATE' )
3976                 );
3977                 # Cache some fields we may want
3978                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3979                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3980                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3981                 $this->mContentModel = $row && isset( $row->page_content_model ) ? strval( $row->page_content_model ) : false;
3982                 if ( !$this->mRedirect ) {
3983                         return false;
3984                 }
3985                 # Does the article have a history?
3986                 $row = $dbw->selectField( array( 'page', 'revision' ),
3987                         'rev_id',
3988                         array( 'page_namespace' => $this->getNamespace(),
3989                                 'page_title' => $this->getDBkey(),
3990                                 'page_id=rev_page',
3991                                 'page_latest != rev_id'
3992                         ),
3993                         __METHOD__,
3994                         array( 'FOR UPDATE' )
3995                 );
3996                 # Return true if there was no history
3997                 return ( $row === false );
3998         }
3999
4000         /**
4001          * Checks if $this can be moved to a given Title
4002          * - Selects for update, so don't call it unless you mean business
4003          *
4004          * @param $nt Title the new title to check
4005          * @return Bool
4006          */
4007         public function isValidMoveTarget( $nt ) {
4008                 # Is it an existing file?
4009                 if ( $nt->getNamespace() == NS_FILE ) {
4010                         $file = wfLocalFile( $nt );
4011                         if ( $file->exists() ) {
4012                                 wfDebug( __METHOD__ . ": file exists\n" );
4013                                 return false;
4014                         }
4015                 }
4016                 # Is it a redirect with no history?
4017                 if ( !$nt->isSingleRevRedirect() ) {
4018                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
4019                         return false;
4020                 }
4021                 # Get the article text
4022                 $rev = Revision::newFromTitle( $nt, false, Revision::READ_LATEST );
4023                 if( !is_object( $rev ) ) {
4024                         return false;
4025                 }
4026                 $content = $rev->getContent();
4027                 # Does the redirect point to the source?
4028                 # Or is it a broken self-redirect, usually caused by namespace collisions?
4029                 $redirTitle = $content ? $content->getRedirectTarget() : null;
4030
4031                 if ( $redirTitle ) {
4032                         if ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
4033                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) {
4034                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
4035                                 return false;
4036                         } else {
4037                                 return true;
4038                         }
4039                 } else {
4040                         # Fail safe (not a redirect after all. strange.)
4041                         wfDebug( __METHOD__ . ": failsafe: database sais " . $nt->getPrefixedDBkey() .
4042                                                 " is a redirect, but it doesn't contain a valid redirect.\n" );
4043                         return false;
4044                 }
4045         }
4046
4047         /**
4048          * Get categories to which this Title belongs and return an array of
4049          * categories' names.
4050          *
4051          * @return Array of parents in the form:
4052          *        $parent => $currentarticle
4053          */
4054         public function getParentCategories() {
4055                 global $wgContLang;
4056
4057                 $data = array();
4058
4059                 $titleKey = $this->getArticleID();
4060
4061                 if ( $titleKey === 0 ) {
4062                         return $data;
4063                 }
4064
4065                 $dbr = wfGetDB( DB_SLAVE );
4066
4067                 $res = $dbr->select(
4068                         'categorylinks',
4069                         'cl_to',
4070                         array( 'cl_from' => $titleKey ),
4071                         __METHOD__
4072                 );
4073
4074                 if ( $res->numRows() > 0 ) {
4075                         foreach ( $res as $row ) {
4076                                 // $data[] = Title::newFromText($wgContLang->getNsText ( NS_CATEGORY ).':'.$row->cl_to);
4077                                 $data[$wgContLang->getNsText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
4078                         }
4079                 }
4080                 return $data;
4081         }
4082
4083         /**
4084          * Get a tree of parent categories
4085          *
4086          * @param array $children with the children in the keys, to check for circular refs
4087          * @return Array Tree of parent categories
4088          */
4089         public function getParentCategoryTree( $children = array() ) {
4090                 $stack = array();
4091                 $parents = $this->getParentCategories();
4092
4093                 if ( $parents ) {
4094                         foreach ( $parents as $parent => $current ) {
4095                                 if ( array_key_exists( $parent, $children ) ) {
4096                                         # Circular reference
4097                                         $stack[$parent] = array();
4098                                 } else {
4099                                         $nt = Title::newFromText( $parent );
4100                                         if ( $nt ) {
4101                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
4102                                         }
4103                                 }
4104                         }
4105                 }
4106
4107                 return $stack;
4108         }
4109
4110         /**
4111          * Get an associative array for selecting this title from
4112          * the "page" table
4113          *
4114          * @return Array suitable for the $where parameter of DB::select()
4115          */
4116         public function pageCond() {
4117                 if ( $this->mArticleID > 0 ) {
4118                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
4119                         return array( 'page_id' => $this->mArticleID );
4120                 } else {
4121                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
4122                 }
4123         }
4124
4125         /**
4126          * Get the revision ID of the previous revision
4127          *
4128          * @param int $revId Revision ID. Get the revision that was before this one.
4129          * @param int $flags Title::GAID_FOR_UPDATE
4130          * @return Int|Bool Old revision ID, or FALSE if none exists
4131          */
4132         public function getPreviousRevisionID( $revId, $flags = 0 ) {
4133                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4134                 $revId = $db->selectField( 'revision', 'rev_id',
4135                         array(
4136                                 'rev_page' => $this->getArticleID( $flags ),
4137                                 'rev_id < ' . intval( $revId )
4138                         ),
4139                         __METHOD__,
4140                         array( 'ORDER BY' => 'rev_id DESC' )
4141                 );
4142
4143                 if ( $revId === false ) {
4144                         return false;
4145                 } else {
4146                         return intval( $revId );
4147                 }
4148         }
4149
4150         /**
4151          * Get the revision ID of the next revision
4152          *
4153          * @param int $revId Revision ID. Get the revision that was after this one.
4154          * @param int $flags Title::GAID_FOR_UPDATE
4155          * @return Int|Bool Next revision ID, or FALSE if none exists
4156          */
4157         public function getNextRevisionID( $revId, $flags = 0 ) {
4158                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4159                 $revId = $db->selectField( 'revision', 'rev_id',
4160                         array(
4161                                 'rev_page' => $this->getArticleID( $flags ),
4162                                 'rev_id > ' . intval( $revId )
4163                         ),
4164                         __METHOD__,
4165                         array( 'ORDER BY' => 'rev_id' )
4166                 );
4167
4168                 if ( $revId === false ) {
4169                         return false;
4170                 } else {
4171                         return intval( $revId );
4172                 }
4173         }
4174
4175         /**
4176          * Get the first revision of the page
4177          *
4178          * @param int $flags Title::GAID_FOR_UPDATE
4179          * @return Revision|Null if page doesn't exist
4180          */
4181         public function getFirstRevision( $flags = 0 ) {
4182                 $pageId = $this->getArticleID( $flags );
4183                 if ( $pageId ) {
4184                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
4185                         $row = $db->selectRow( 'revision', Revision::selectFields(),
4186                                 array( 'rev_page' => $pageId ),
4187                                 __METHOD__,
4188                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
4189                         );
4190                         if ( $row ) {
4191                                 return new Revision( $row );
4192                         }
4193                 }
4194                 return null;
4195         }
4196
4197         /**
4198          * Get the oldest revision timestamp of this page
4199          *
4200          * @param int $flags Title::GAID_FOR_UPDATE
4201          * @return String: MW timestamp
4202          */
4203         public function getEarliestRevTime( $flags = 0 ) {
4204                 $rev = $this->getFirstRevision( $flags );
4205                 return $rev ? $rev->getTimestamp() : null;
4206         }
4207
4208         /**
4209          * Check if this is a new page
4210          *
4211          * @return bool
4212          */
4213         public function isNewPage() {
4214                 $dbr = wfGetDB( DB_SLAVE );
4215                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
4216         }
4217
4218         /**
4219          * Check whether the number of revisions of this page surpasses $wgDeleteRevisionsLimit
4220          *
4221          * @return bool
4222          */
4223         public function isBigDeletion() {
4224                 global $wgDeleteRevisionsLimit;
4225
4226                 if ( !$wgDeleteRevisionsLimit ) {
4227                         return false;
4228                 }
4229
4230                 $revCount = $this->estimateRevisionCount();
4231                 return $revCount > $wgDeleteRevisionsLimit;
4232         }
4233
4234         /**
4235          * Get the  approximate revision count of this page.
4236          *
4237          * @return int
4238          */
4239         public function estimateRevisionCount() {
4240                 if ( !$this->exists() ) {
4241                         return 0;
4242                 }
4243
4244                 if ( $this->mEstimateRevisions === null ) {
4245                         $dbr = wfGetDB( DB_SLAVE );
4246                         $this->mEstimateRevisions = $dbr->estimateRowCount( 'revision', '*',
4247                                 array( 'rev_page' => $this->getArticleID() ), __METHOD__ );
4248                 }
4249
4250                 return $this->mEstimateRevisions;
4251         }
4252
4253         /**
4254          * Get the number of revisions between the given revision.
4255          * Used for diffs and other things that really need it.
4256          *
4257          * @param int|Revision $old Old revision or rev ID (first before range)
4258          * @param int|Revision $new New revision or rev ID (first after range)
4259          * @return Int Number of revisions between these revisions.
4260          */
4261         public function countRevisionsBetween( $old, $new ) {
4262                 if ( !( $old instanceof Revision ) ) {
4263                         $old = Revision::newFromTitle( $this, (int)$old );
4264                 }
4265                 if ( !( $new instanceof Revision ) ) {
4266                         $new = Revision::newFromTitle( $this, (int)$new );
4267                 }
4268                 if ( !$old || !$new ) {
4269                         return 0; // nothing to compare
4270                 }
4271                 $dbr = wfGetDB( DB_SLAVE );
4272                 return (int)$dbr->selectField( 'revision', 'count(*)',
4273                         array(
4274                                 'rev_page' => $this->getArticleID(),
4275                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4276                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4277                         ),
4278                         __METHOD__
4279                 );
4280         }
4281
4282         /**
4283          * Get the number of authors between the given revisions or revision IDs.
4284          * Used for diffs and other things that really need it.
4285          *
4286          * @param int|Revision $old Old revision or rev ID (first before range by default)
4287          * @param int|Revision $new New revision or rev ID (first after range by default)
4288          * @param int $limit Maximum number of authors
4289          * @param string|array $options (Optional): Single option, or an array of options:
4290          *     'include_old' Include $old in the range; $new is excluded.
4291          *     'include_new' Include $new in the range; $old is excluded.
4292          *     'include_both' Include both $old and $new in the range.
4293          *     Unknown option values are ignored.
4294          * @return int Number of revision authors in the range; zero if not both revisions exist
4295          */
4296         public function countAuthorsBetween( $old, $new, $limit, $options = array() ) {
4297                 if ( !( $old instanceof Revision ) ) {
4298                         $old = Revision::newFromTitle( $this, (int)$old );
4299                 }
4300                 if ( !( $new instanceof Revision ) ) {
4301                         $new = Revision::newFromTitle( $this, (int)$new );
4302                 }
4303                 // XXX: what if Revision objects are passed in, but they don't refer to this title?
4304                 // Add $old->getPage() != $new->getPage() || $old->getPage() != $this->getArticleID()
4305                 // in the sanity check below?
4306                 if ( !$old || !$new ) {
4307                         return 0; // nothing to compare
4308                 }
4309                 $old_cmp = '>';
4310                 $new_cmp = '<';
4311                 $options = (array)$options;
4312                 if ( in_array( 'include_old', $options ) ) {
4313                         $old_cmp = '>=';
4314                 }
4315                 if ( in_array( 'include_new', $options ) ) {
4316                         $new_cmp = '<=';
4317                 }
4318                 if ( in_array( 'include_both', $options ) ) {
4319                         $old_cmp = '>=';
4320                         $new_cmp = '<=';
4321                 }
4322                 // No DB query needed if $old and $new are the same or successive revisions:
4323                 if ( $old->getId() === $new->getId() ) {
4324                         return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4325                 } else if ( $old->getId() === $new->getParentId() ) {
4326                         if ( $old_cmp === '>' || $new_cmp === '<' ) {
4327                                 return ( $old_cmp === '>' && $new_cmp === '<' ) ? 0 : 1;
4328                         }
4329                         return ( $old->getRawUserText() === $new->getRawUserText() ) ? 1 : 2;
4330                 }
4331                 $dbr = wfGetDB( DB_SLAVE );
4332                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
4333                         array(
4334                                 'rev_page' => $this->getArticleID(),
4335                                 "rev_timestamp $old_cmp " . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
4336                                 "rev_timestamp $new_cmp " . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
4337                         ), __METHOD__,
4338                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
4339                 );
4340                 return (int)$dbr->numRows( $res );
4341         }
4342
4343         /**
4344          * Compare with another title.
4345          *
4346          * @param $title Title
4347          * @return Bool
4348          */
4349         public function equals( Title $title ) {
4350                 // Note: === is necessary for proper matching of number-like titles.
4351                 return $this->getInterwiki() === $title->getInterwiki()
4352                         && $this->getNamespace() == $title->getNamespace()
4353                         && $this->getDBkey() === $title->getDBkey();
4354         }
4355
4356         /**
4357          * Check if this title is a subpage of another title
4358          *
4359          * @param $title Title
4360          * @return Bool
4361          */
4362         public function isSubpageOf( Title $title ) {
4363                 return $this->getInterwiki() === $title->getInterwiki()
4364                         && $this->getNamespace() == $title->getNamespace()
4365                         && strpos( $this->getDBkey(), $title->getDBkey() . '/' ) === 0;
4366         }
4367
4368         /**
4369          * Check if page exists.  For historical reasons, this function simply
4370          * checks for the existence of the title in the page table, and will
4371          * thus return false for interwiki links, special pages and the like.
4372          * If you want to know if a title can be meaningfully viewed, you should
4373          * probably call the isKnown() method instead.
4374          *
4375          * @return Bool
4376          */
4377         public function exists() {
4378                 return $this->getArticleID() != 0;
4379         }
4380
4381         /**
4382          * Should links to this title be shown as potentially viewable (i.e. as
4383          * "bluelinks"), even if there's no record by this title in the page
4384          * table?
4385          *
4386          * This function is semi-deprecated for public use, as well as somewhat
4387          * misleadingly named.  You probably just want to call isKnown(), which
4388          * calls this function internally.
4389          *
4390          * (ISSUE: Most of these checks are cheap, but the file existence check
4391          * can potentially be quite expensive.  Including it here fixes a lot of
4392          * existing code, but we might want to add an optional parameter to skip
4393          * it and any other expensive checks.)
4394          *
4395          * @return Bool
4396          */
4397         public function isAlwaysKnown() {
4398                 $isKnown = null;
4399
4400                 /**
4401                  * Allows overriding default behavior for determining if a page exists.
4402                  * If $isKnown is kept as null, regular checks happen. If it's
4403                  * a boolean, this value is returned by the isKnown method.
4404                  *
4405                  * @since 1.20
4406                  *
4407                  * @param Title $title
4408                  * @param boolean|null $isKnown
4409                  */
4410                 wfRunHooks( 'TitleIsAlwaysKnown', array( $this, &$isKnown ) );
4411
4412                 if ( !is_null( $isKnown ) ) {
4413                         return $isKnown;
4414                 }
4415
4416                 if ( $this->mInterwiki != '' ) {
4417                         return true;  // any interwiki link might be viewable, for all we know
4418                 }
4419
4420                 switch( $this->mNamespace ) {
4421                         case NS_MEDIA:
4422                         case NS_FILE:
4423                                 // file exists, possibly in a foreign repo
4424                                 return (bool)wfFindFile( $this );
4425                         case NS_SPECIAL:
4426                                 // valid special page
4427                                 return SpecialPageFactory::exists( $this->getDBkey() );
4428                         case NS_MAIN:
4429                                 // selflink, possibly with fragment
4430                                 return $this->mDbkeyform == '';
4431                         case NS_MEDIAWIKI:
4432                                 // known system message
4433                                 return $this->hasSourceText() !== false;
4434                         default:
4435                                 return false;
4436                 }
4437         }
4438
4439         /**
4440          * Does this title refer to a page that can (or might) be meaningfully
4441          * viewed?  In particular, this function may be used to determine if
4442          * links to the title should be rendered as "bluelinks" (as opposed to
4443          * "redlinks" to non-existent pages).
4444          * Adding something else to this function will cause inconsistency
4445          * since LinkHolderArray calls isAlwaysKnown() and does its own
4446          * page existence check.
4447          *
4448          * @return Bool
4449          */
4450         public function isKnown() {
4451                 return $this->isAlwaysKnown() || $this->exists();
4452         }
4453
4454         /**
4455          * Does this page have source text?
4456          *
4457          * @return Boolean
4458          */
4459         public function hasSourceText() {
4460                 if ( $this->exists() ) {
4461                         return true;
4462                 }
4463
4464                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
4465                         // If the page doesn't exist but is a known system message, default
4466                         // message content will be displayed, same for language subpages-
4467                         // Use always content language to avoid loading hundreds of languages
4468                         // to get the link color.
4469                         global $wgContLang;
4470                         list( $name, ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4471                         $message = wfMessage( $name )->inLanguage( $wgContLang )->useDatabase( false );
4472                         return $message->exists();
4473                 }
4474
4475                 return false;
4476         }
4477
4478         /**
4479          * Get the default message text or false if the message doesn't exist
4480          *
4481          * @return String or false
4482          */
4483         public function getDefaultMessageText() {
4484                 global $wgContLang;
4485
4486                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
4487                         return false;
4488                 }
4489
4490                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
4491                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
4492
4493                 if ( $message->exists() ) {
4494                         return $message->plain();
4495                 } else {
4496                         return false;
4497                 }
4498         }
4499
4500         /**
4501          * Updates page_touched for this page; called from LinksUpdate.php
4502          *
4503          * @return Bool true if the update succeeded
4504          */
4505         public function invalidateCache() {
4506                 global $wgMemc;
4507
4508                 if ( wfReadOnly() ) {
4509                         return false;
4510                 }
4511
4512                 $dbw = wfGetDB( DB_MASTER );
4513                 $conds = $this->pageCond();
4514                 $dbw->onTransactionIdle( function() use ( $dbw, $conds ) {
4515                         $dbw->update(
4516                                 'page',
4517                                 array( 'page_touched' => $dbw->timestamp() ),
4518                                 $conds,
4519                                 __METHOD__
4520                         );
4521                 } );
4522                 HTMLFileCache::clearFileCache( $this );
4523
4524                 // Clear page info.
4525                 $revision = WikiPage::factory( $this )->getRevision();
4526                 if ( $revision !== null ) {
4527                         $memcKey = wfMemcKey( 'infoaction', $this->getPrefixedText(), $revision->getId() );
4528                         $success = $wgMemc->delete( $memcKey );
4529                 } else {
4530                         $success = true;
4531                 }
4532
4533                 return $success;
4534         }
4535
4536         /**
4537          * Update page_touched timestamps and send squid purge messages for
4538          * pages linking to this title. May be sent to the job queue depending
4539          * on the number of links. Typically called on create and delete.
4540          */
4541         public function touchLinks() {
4542                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
4543                 $u->doUpdate();
4544
4545                 if ( $this->getNamespace() == NS_CATEGORY ) {
4546                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
4547                         $u->doUpdate();
4548                 }
4549         }
4550
4551         /**
4552          * Get the last touched timestamp
4553          *
4554          * @param $db DatabaseBase: optional db
4555          * @return String last-touched timestamp
4556          */
4557         public function getTouched( $db = null ) {
4558                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
4559                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
4560                 return $touched;
4561         }
4562
4563         /**
4564          * Get the timestamp when this page was updated since the user last saw it.
4565          *
4566          * @param $user User
4567          * @return String|Null
4568          */
4569         public function getNotificationTimestamp( $user = null ) {
4570                 global $wgUser, $wgShowUpdatedMarker;
4571                 // Assume current user if none given
4572                 if ( !$user ) {
4573                         $user = $wgUser;
4574                 }
4575                 // Check cache first
4576                 $uid = $user->getId();
4577                 // avoid isset here, as it'll return false for null entries
4578                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
4579                         return $this->mNotificationTimestamp[$uid];
4580                 }
4581                 if ( !$uid || !$wgShowUpdatedMarker ) {
4582                         return $this->mNotificationTimestamp[$uid] = false;
4583                 }
4584                 // Don't cache too much!
4585                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
4586                         $this->mNotificationTimestamp = array();
4587                 }
4588                 $dbr = wfGetDB( DB_SLAVE );
4589                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
4590                         'wl_notificationtimestamp',
4591                         array(
4592                                 'wl_user' => $user->getId(),
4593                                 'wl_namespace' => $this->getNamespace(),
4594                                 'wl_title' => $this->getDBkey(),
4595                         ),
4596                         __METHOD__
4597                 );
4598                 return $this->mNotificationTimestamp[$uid];
4599         }
4600
4601         /**
4602          * Generate strings used for xml 'id' names in monobook tabs
4603          *
4604          * @param string $prepend defaults to 'nstab-'
4605          * @return String XML 'id' name
4606          */
4607         public function getNamespaceKey( $prepend = 'nstab-' ) {
4608                 global $wgContLang;
4609                 // Gets the subject namespace if this title
4610                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4611                 // Checks if canonical namespace name exists for namespace
4612                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4613                         // Uses canonical namespace name
4614                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4615                 } else {
4616                         // Uses text of namespace
4617                         $namespaceKey = $this->getSubjectNsText();
4618                 }
4619                 // Makes namespace key lowercase
4620                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4621                 // Uses main
4622                 if ( $namespaceKey == '' ) {
4623                         $namespaceKey = 'main';
4624                 }
4625                 // Changes file to image for backwards compatibility
4626                 if ( $namespaceKey == 'file' ) {
4627                         $namespaceKey = 'image';
4628                 }
4629                 return $prepend . $namespaceKey;
4630         }
4631
4632         /**
4633          * Get all extant redirects to this Title
4634          *
4635          * @param int|Null $ns Single namespace to consider; NULL to consider all namespaces
4636          * @return Array of Title redirects to this title
4637          */
4638         public function getRedirectsHere( $ns = null ) {
4639                 $redirs = array();
4640
4641                 $dbr = wfGetDB( DB_SLAVE );
4642                 $where = array(
4643                         'rd_namespace' => $this->getNamespace(),
4644                         'rd_title' => $this->getDBkey(),
4645                         'rd_from = page_id'
4646                 );
4647                 if ( $this->isExternal() ) {
4648                         $where['rd_interwiki'] = $this->getInterwiki();
4649                 } else {
4650                         $where[] = 'rd_interwiki = ' . $dbr->addQuotes( '' ) . ' OR rd_interwiki IS NULL';
4651                 }
4652                 if ( !is_null( $ns ) ) {
4653                         $where['page_namespace'] = $ns;
4654                 }
4655
4656                 $res = $dbr->select(
4657                         array( 'redirect', 'page' ),
4658                         array( 'page_namespace', 'page_title' ),
4659                         $where,
4660                         __METHOD__
4661                 );
4662
4663                 foreach ( $res as $row ) {
4664                         $redirs[] = self::newFromRow( $row );
4665                 }
4666                 return $redirs;
4667         }
4668
4669         /**
4670          * Check if this Title is a valid redirect target
4671          *
4672          * @return Bool
4673          */
4674         public function isValidRedirectTarget() {
4675                 global $wgInvalidRedirectTargets;
4676
4677                 // invalid redirect targets are stored in a global array, but explicitly disallow Userlogout here
4678                 if ( $this->isSpecial( 'Userlogout' ) ) {
4679                         return false;
4680                 }
4681
4682                 foreach ( $wgInvalidRedirectTargets as $target ) {
4683                         if ( $this->isSpecial( $target ) ) {
4684                                 return false;
4685                         }
4686                 }
4687
4688                 return true;
4689         }
4690
4691         /**
4692          * Get a backlink cache object
4693          *
4694          * @return BacklinkCache
4695          */
4696         public function getBacklinkCache() {
4697                 return BacklinkCache::get( $this );
4698         }
4699
4700         /**
4701          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4702          *
4703          * @return Boolean
4704          */
4705         public function canUseNoindex() {
4706                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4707
4708                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4709                         ? $wgContentNamespaces
4710                         : $wgExemptFromUserRobotsControl;
4711
4712                 return !in_array( $this->mNamespace, $bannedNamespaces );
4713
4714         }
4715
4716         /**
4717          * Returns the raw sort key to be used for categories, with the specified
4718          * prefix.  This will be fed to Collation::getSortKey() to get a
4719          * binary sortkey that can be used for actual sorting.
4720          *
4721          * @param string $prefix The prefix to be used, specified using
4722          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4723          *   prefix.
4724          * @return string
4725          */
4726         public function getCategorySortkey( $prefix = '' ) {
4727                 $unprefixed = $this->getText();
4728
4729                 // Anything that uses this hook should only depend
4730                 // on the Title object passed in, and should probably
4731                 // tell the users to run updateCollations.php --force
4732                 // in order to re-sort existing category relations.
4733                 wfRunHooks( 'GetDefaultSortkey', array( $this, &$unprefixed ) );
4734                 if ( $prefix !== '' ) {
4735                         # Separate with a line feed, so the unprefixed part is only used as
4736                         # a tiebreaker when two pages have the exact same prefix.
4737                         # In UCA, tab is the only character that can sort above LF
4738                         # so we strip both of them from the original prefix.
4739                         $prefix = strtr( $prefix, "\n\t", '  ' );
4740                         return "$prefix\n$unprefixed";
4741                 }
4742                 return $unprefixed;
4743         }
4744
4745         /**
4746          * Get the language in which the content of this page is written in
4747          * wikitext. Defaults to $wgContLang, but in certain cases it can be
4748          * e.g. $wgLang (such as special pages, which are in the user language).
4749          *
4750          * @since 1.18
4751          * @return Language
4752          */
4753         public function getPageLanguage() {
4754                 global $wgLang;
4755                 if ( $this->isSpecialPage() ) {
4756                         // special pages are in the user language
4757                         return $wgLang;
4758                 }
4759
4760                 //TODO: use the LinkCache to cache this! Note that this may depend on user settings, so the cache should be only per-request.
4761                 //NOTE: ContentHandler::getPageLanguage() may need to load the content to determine the page language!
4762                 $contentHandler = ContentHandler::getForTitle( $this );
4763                 $pageLang = $contentHandler->getPageLanguage( $this );
4764
4765                 return wfGetLangObj( $pageLang );
4766         }
4767
4768         /**
4769          * Get the language in which the content of this page is written when
4770          * viewed by user. Defaults to $wgContLang, but in certain cases it can be
4771          * e.g. $wgLang (such as special pages, which are in the user language).
4772          *
4773          * @since 1.20
4774          * @return Language
4775          */
4776         public function getPageViewLanguage() {
4777                 global $wgLang;
4778
4779                 if ( $this->isSpecialPage() ) {
4780                         // If the user chooses a variant, the content is actually
4781                         // in a language whose code is the variant code.
4782                         $variant = $wgLang->getPreferredVariant();
4783                         if ( $wgLang->getCode() !== $variant ) {
4784                                 return Language::factory( $variant );
4785                         }
4786
4787                         return $wgLang;
4788                 }
4789
4790                 //NOTE: can't be cached persistently, depends on user settings
4791                 //NOTE: ContentHandler::getPageViewLanguage() may need to load the content to determine the page language!
4792                 $contentHandler = ContentHandler::getForTitle( $this );
4793                 $pageLang = $contentHandler->getPageViewLanguage( $this );
4794                 return $pageLang;
4795         }
4796
4797         /**
4798          * Get a list of rendered edit notices for this page.
4799          *
4800          * Array is keyed by the original message key, and values are rendered using parseAsBlock, so
4801          * they will already be wrapped in paragraphs.
4802          *
4803          * @since 1.21
4804          * @return Array
4805          */
4806         public function getEditNotices() {
4807                 $notices = array();
4808
4809                 # Optional notices on a per-namespace and per-page basis
4810                 $editnotice_ns = 'editnotice-' . $this->getNamespace();
4811                 $editnotice_ns_message = wfMessage( $editnotice_ns );
4812                 if ( $editnotice_ns_message->exists() ) {
4813                         $notices[$editnotice_ns] = $editnotice_ns_message->parseAsBlock();
4814                 }
4815                 if ( MWNamespace::hasSubpages( $this->getNamespace() ) ) {
4816                         $parts = explode( '/', $this->getDBkey() );
4817                         $editnotice_base = $editnotice_ns;
4818                         while ( count( $parts ) > 0 ) {
4819                                 $editnotice_base .= '-' . array_shift( $parts );
4820                                 $editnotice_base_msg = wfMessage( $editnotice_base );
4821                                 if ( $editnotice_base_msg->exists() ) {
4822                                         $notices[$editnotice_base] = $editnotice_base_msg->parseAsBlock();
4823                                 }
4824                         }
4825                 } else {
4826                         # Even if there are no subpages in namespace, we still don't want / in MW ns.
4827                         $editnoticeText = $editnotice_ns . '-' . str_replace( '/', '-', $this->getDBkey() );
4828                         $editnoticeMsg = wfMessage( $editnoticeText );
4829                         if ( $editnoticeMsg->exists() ) {
4830                                 $notices[$editnoticeText] = $editnoticeMsg->parseAsBlock();
4831                         }
4832                 }
4833                 return $notices;
4834         }
4835 }