includes/job/jobs/DoubleRedirectJob.php

   1 <?php
   2 /**
   3  * Job to fix double redirects after moving a page.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup JobQueue
  22  */
  23
  24 /**
  25  * Job to fix double redirects after moving a page
  26  *
  27  * @ingroup JobQueue
  28  */
  29 class DoubleRedirectJob extends Job {
  30         /** @var string Reason for the change, 'maintenance' or 'move'. Suffix fo
  31          *    message key 'double-redirect-fixed-'.
  32          */
  33         private $reason;
  34
  35         /** @var Title The title which has changed, redirects pointing to this
  36          *    title are fixed
  37          */
  38         private $redirTitle;
  39
  40         /** @var User */
  41         private static $user;
  42
  43         /**
  44          * Insert jobs into the job queue to fix redirects to the given title
  45          * @param string $reason the reason for the fix, see message
  46          *   "double-redirect-fixed-<reason>"
  47          * @param $redirTitle Title: the title which has changed, redirects
  48          *   pointing to this title are fixed
  49          * @param bool $destTitle Not used
  50          */
  51         public static function fixRedirects( $reason, $redirTitle, $destTitle = false ) {
  52                 # Need to use the master to get the redirect table updated in the same transaction
  53                 $dbw = wfGetDB( DB_MASTER );
  54                 $res = $dbw->select(
  55                         array( 'redirect', 'page' ),
  56                         array( 'page_namespace', 'page_title' ),
  57                         array(
  58                                 'page_id = rd_from',
  59                                 'rd_namespace' => $redirTitle->getNamespace(),
  60                                 'rd_title' => $redirTitle->getDBkey()
  61                         ), __METHOD__ );
  62                 if ( !$res->numRows() ) {
  63                         return;
  64                 }
  65                 $jobs = array();
  66                 foreach ( $res as $row ) {
  67                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
  68                         if ( !$title ) {
  69                                 continue;
  70                         }
  71
  72                         $jobs[] = new self( $title, array(
  73                                 'reason' => $reason,
  74                                 'redirTitle' => $redirTitle->getPrefixedDBkey() ) );
  75                         # Avoid excessive memory usage
  76                         if ( count( $jobs ) > 10000 ) {
  77                                 JobQueueGroup::singleton()->push( $jobs );
  78                                 $jobs = array();
  79                         }
  80                 }
  81                 JobQueueGroup::singleton()->push( $jobs );
  82         }
  83
  84         /**
  85          * @param Title $title
  86          * @param array|bool $params
  87          * @param int $id
  88          */
  89         function __construct( $title, $params = false, $id = 0 ) {
  90                 parent::__construct( 'fixDoubleRedirect', $title, $params, $id );
  91                 $this->reason = $params['reason'];
  92                 $this->redirTitle = Title::newFromText( $params['redirTitle'] );
  93         }
  94
  95         /**
  96          * @return bool
  97          */
  98         function run() {
  99                 if ( !$this->redirTitle ) {
 100                         $this->setLastError( 'Invalid title' );
 101
 102                         return false;
 103                 }
 104
 105                 $targetRev = Revision::newFromTitle( $this->title, false, Revision::READ_LATEST );
 106                 if ( !$targetRev ) {
 107                         wfDebug( __METHOD__ . ": target redirect already deleted, ignoring\n" );
 108
 109                         return true;
 110                 }
 111                 $content = $targetRev->getContent();
 112                 $currentDest = $content ? $content->getRedirectTarget() : null;
 113                 if ( !$currentDest || !$currentDest->equals( $this->redirTitle ) ) {
 114                         wfDebug( __METHOD__ . ": Redirect has changed since the job was queued\n" );
 115
 116                         return true;
 117                 }
 118
 119                 // Check for a suppression tag (used e.g. in periodically archived discussions)
 120                 $mw = MagicWord::get( 'staticredirect' );
 121                 if ( $content->matchMagicWord( $mw ) ) {
 122                         wfDebug( __METHOD__ . ": skipping: suppressed with __STATICREDIRECT__\n" );
 123
 124                         return true;
 125                 }
 126
 127                 // Find the current final destination
 128                 $newTitle = self::getFinalDestination( $this->redirTitle );
 129                 if ( !$newTitle ) {
 130                         wfDebug( __METHOD__ .
 131                                 ": skipping: single redirect, circular redirect or invalid redirect destination\n" );
 132
 133                         return true;
 134                 }
 135                 if ( $newTitle->equals( $this->redirTitle ) ) {
 136                         // The redirect is already right, no need to change it
 137                         // This can happen if the page was moved back (say after vandalism)
 138                         wfDebug( __METHOD__ . " : skipping, already good\n" );
 139                 }
 140
 141                 // Preserve fragment (bug 14904)
 142                 $newTitle = Title::makeTitle( $newTitle->getNamespace(), $newTitle->getDBkey(),
 143                         $currentDest->getFragment(), $newTitle->getInterwiki() );
 144
 145                 // Fix the text
 146                 $newContent = $content->updateRedirect( $newTitle );
 147
 148                 if ( $newContent->equals( $content ) ) {
 149                         $this->setLastError( 'Content unchanged???' );
 150
 151                         return false;
 152                 }
 153
 154                 $user = $this->getUser();
 155                 if ( !$user ) {
 156                         $this->setLastError( 'Invalid user' );
 157
 158                         return false;
 159                 }
 160
 161                 // Save it
 162                 global $wgUser;
 163                 $oldUser = $wgUser;
 164                 $wgUser = $user;
 165                 $article = WikiPage::factory( $this->title );
 166
 167                 // Messages: double-redirect-fixed-move, double-redirect-fixed-maintenance
 168                 $reason = wfMessage( 'double-redirect-fixed-' . $this->reason,
 169                         $this->redirTitle->getPrefixedText(), $newTitle->getPrefixedText()
 170                 )->inContentLanguage()->text();
 171                 $article->doEditContent( $newContent, $reason, EDIT_UPDATE | EDIT_SUPPRESS_RC, false, $user );
 172                 $wgUser = $oldUser;
 173
 174                 return true;
 175         }
 176
 177         /**
 178          * Get the final destination of a redirect
 179          *
 180          * @param $title Title
 181          *
 182          * @return bool if the specified title is not a redirect, or if it is a circular redirect
 183          */
 184         public static function getFinalDestination( $title ) {
 185                 $dbw = wfGetDB( DB_MASTER );
 186
 187                 // Circular redirect check
 188                 $seenTitles = array();
 189                 $dest = false;
 190
 191                 while ( true ) {
 192                         $titleText = $title->getPrefixedDBkey();
 193                         if ( isset( $seenTitles[$titleText] ) ) {
 194                                 wfDebug( __METHOD__, "Circular redirect detected, aborting\n" );
 195
 196                                 return false;
 197                         }
 198                         $seenTitles[$titleText] = true;
 199
 200                         if ( $title->getInterwiki() ) {
 201                                 // If the target is interwiki, we have to break early (bug 40352).
 202                                 // Otherwise it will look up a row in the local page table
 203                                 // with the namespace/page of the interwiki target which can cause
 204                                 // unexpected results (e.g. X -> foo:Bar -> Bar -> .. )
 205                                 break;
 206                         }
 207
 208                         $row = $dbw->selectRow(
 209                                 array( 'redirect', 'page' ),
 210                                 array( 'rd_namespace', 'rd_title', 'rd_interwiki' ),
 211                                 array(
 212                                         'rd_from=page_id',
 213                                         'page_namespace' => $title->getNamespace(),
 214                                         'page_title' => $title->getDBkey()
 215                                 ), __METHOD__ );
 216                         if ( !$row ) {
 217                                 # No redirect from here, chain terminates
 218                                 break;
 219                         } else {
 220                                 $dest = $title = Title::makeTitle(
 221                                         $row->rd_namespace,
 222                                         $row->rd_title,
 223                                         '',
 224                                         $row->rd_interwiki
 225                                 );
 226                         }
 227                 }
 228
 229                 return $dest;
 230         }
 231
 232         /**
 233          * Get a user object for doing edits, from a request-lifetime cache
 234          * False will be returned if the user name specified in the
 235          * 'double-redirect-fixer' message is invalid.
 236          *
 237          * @return User|bool
 238          */
 239         function getUser() {
 240                 if ( !self::$user ) {
 241                         $username = wfMessage( 'double-redirect-fixer' )->inContentLanguage()->text();
 242                         self::$user = User::newFromName( $username );
 243                         # User::newFromName() can return false on a badly configured wiki.
 244                         if ( self::$user && !self::$user->isLoggedIn() ) {
 245                                 self::$user->addToDatabase();
 246                         }
 247                 }
 248
 249                 return self::$user;
 250         }
 251 }