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