includes/jobqueue/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          * @param Title $title
  45          * @param array $params
  46          */
  47         function __construct( Title $title, array $params ) {
  48                 parent::__construct( 'fixDoubleRedirect', $title, $params );
  49                 $this->reason = $params['reason'];
  50                 $this->redirTitle = Title::newFromText( $params['redirTitle'] );
  51         }
  52
  53         /**
  54          * Insert jobs into the job queue to fix redirects to the given title
  55          * @param string $reason The reason for the fix, see message
  56          *   "double-redirect-fixed-<reason>"
  57          * @param Title $redirTitle The title which has changed, redirects
  58          *   pointing to this title are fixed
  59          * @param bool $destTitle Not used
  60          */
  61         public static function fixRedirects( $reason, $redirTitle, $destTitle = false ) {
  62                 # Need to use the master to get the redirect table updated in the same transaction
  63                 $dbw = wfGetDB( DB_MASTER );
  64                 $res = $dbw->select(
  65                         array( 'redirect', 'page' ),
  66                         array( 'page_namespace', 'page_title' ),
  67                         array(
  68                                 'page_id = rd_from',
  69                                 'rd_namespace' => $redirTitle->getNamespace(),
  70                                 'rd_title' => $redirTitle->getDBkey()
  71                         ), __METHOD__ );
  72                 if ( !$res->numRows() ) {
  73                         return;
  74                 }
  75                 $jobs = array();
  76                 foreach ( $res as $row ) {
  77                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
  78                         if ( !$title ) {
  79                                 continue;
  80                         }
  81
  82                         $jobs[] = new self( $title, array(
  83                                 'reason' => $reason,
  84                                 'redirTitle' => $redirTitle->getPrefixedDBkey() ) );
  85                         # Avoid excessive memory usage
  86                         if ( count( $jobs ) > 10000 ) {
  87                                 JobQueueGroup::singleton()->push( $jobs );
  88                                 $jobs = array();
  89                         }
  90                 }
  91                 JobQueueGroup::singleton()->push( $jobs );
  92         }
  93
  94         /**
  95          * @return bool
  96          */
  97         function run() {
  98                 if ( !$this->redirTitle ) {
  99                         $this->setLastError( 'Invalid title' );
 100
 101                         return false;
 102                 }
 103
 104                 $targetRev = Revision::newFromTitle( $this->title, false, Revision::READ_LATEST );
 105                 if ( !$targetRev ) {
 106                         wfDebug( __METHOD__ . ": target redirect already deleted, ignoring\n" );
 107
 108                         return true;
 109                 }
 110                 $content = $targetRev->getContent();
 111                 $currentDest = $content ? $content->getRedirectTarget() : null;
 112                 if ( !$currentDest || !$currentDest->equals( $this->redirTitle ) ) {
 113                         wfDebug( __METHOD__ . ": Redirect has changed since the job was queued\n" );
 114
 115                         return true;
 116                 }
 117
 118                 // Check for a suppression tag (used e.g. in periodically archived discussions)
 119                 $mw = MagicWord::get( 'staticredirect' );
 120                 if ( $content->matchMagicWord( $mw ) ) {
 121                         wfDebug( __METHOD__ . ": skipping: suppressed with __STATICREDIRECT__\n" );
 122
 123                         return true;
 124                 }
 125
 126                 // Find the current final destination
 127                 $newTitle = self::getFinalDestination( $this->redirTitle );
 128                 if ( !$newTitle ) {
 129                         wfDebug( __METHOD__ .
 130                                 ": skipping: single redirect, circular redirect or invalid redirect destination\n" );
 131
 132                         return true;
 133                 }
 134                 if ( $newTitle->equals( $this->redirTitle ) ) {
 135                         // The redirect is already right, no need to change it
 136                         // This can happen if the page was moved back (say after vandalism)
 137                         wfDebug( __METHOD__ . " : skipping, already good\n" );
 138                 }
 139
 140                 // Preserve fragment (bug 14904)
 141                 $newTitle = Title::makeTitle( $newTitle->getNamespace(), $newTitle->getDBkey(),
 142                         $currentDest->getFragment(), $newTitle->getInterwiki() );
 143
 144                 // Fix the text
 145                 $newContent = $content->updateRedirect( $newTitle );
 146
 147                 if ( $newContent->equals( $content ) ) {
 148                         $this->setLastError( 'Content unchanged???' );
 149
 150                         return false;
 151                 }
 152
 153                 $user = $this->getUser();
 154                 if ( !$user ) {
 155                         $this->setLastError( 'Invalid user' );
 156
 157                         return false;
 158                 }
 159
 160                 // Save it
 161                 global $wgUser;
 162                 $oldUser = $wgUser;
 163                 $wgUser = $user;
 164                 $article = WikiPage::factory( $this->title );
 165
 166                 // Messages: double-redirect-fixed-move, double-redirect-fixed-maintenance
 167                 $reason = wfMessage( 'double-redirect-fixed-' . $this->reason,
 168                         $this->redirTitle->getPrefixedText(), $newTitle->getPrefixedText()
 169                 )->inContentLanguage()->text();
 170                 $article->doEditContent( $newContent, $reason, EDIT_UPDATE | EDIT_SUPPRESS_RC, false, $user );
 171                 $wgUser = $oldUser;
 172
 173                 return true;
 174         }
 175
 176         /**
 177          * Get the final destination of a redirect
 178          *
 179          * @param Title $title
 180          *
 181          * @return bool If the specified title is not a redirect, or if it is a circular redirect
 182          */
 183         public static function getFinalDestination( $title ) {
 184                 $dbw = wfGetDB( DB_MASTER );
 185
 186                 // Circular redirect check
 187                 $seenTitles = array();
 188                 $dest = false;
 189
 190                 while ( true ) {
 191                         $titleText = $title->getPrefixedDBkey();
 192                         if ( isset( $seenTitles[$titleText] ) ) {
 193                                 wfDebug( __METHOD__, "Circular redirect detected, aborting\n" );
 194
 195                                 return false;
 196                         }
 197                         $seenTitles[$titleText] = true;
 198
 199                         if ( $title->isExternal() ) {
 200                                 // If the target is interwiki, we have to break early (bug 40352).
 201                                 // Otherwise it will look up a row in the local page table
 202                                 // with the namespace/page of the interwiki target which can cause
 203                                 // unexpected results (e.g. X -> foo:Bar -> Bar -> .. )
 204                                 break;
 205                         }
 206
 207                         $row = $dbw->selectRow(
 208                                 array( 'redirect', 'page' ),
 209                                 array( 'rd_namespace', 'rd_title', 'rd_interwiki' ),
 210                                 array(
 211                                         'rd_from=page_id',
 212                                         'page_namespace' => $title->getNamespace(),
 213                                         'page_title' => $title->getDBkey()
 214                                 ), __METHOD__ );
 215                         if ( !$row ) {
 216                                 # No redirect from here, chain terminates
 217                                 break;
 218                         } else {
 219                                 $dest = $title = Title::makeTitle(
 220                                         $row->rd_namespace,
 221                                         $row->rd_title,
 222                                         '',
 223                                         $row->rd_interwiki
 224                                 );
 225                         }
 226                 }
 227
 228                 return $dest;
 229         }
 230
 231         /**
 232          * Get a user object for doing edits, from a request-lifetime cache
 233          * False will be returned if the user name specified in the
 234          * 'double-redirect-fixer' message is invalid.
 235          *
 236          * @return User|bool
 237          */
 238         function getUser() {
 239                 if ( !self::$user ) {
 240                         $username = wfMessage( 'double-redirect-fixer' )->inContentLanguage()->text();
 241                         self::$user = User::newFromName( $username );
 242                         # User::newFromName() can return false on a badly configured wiki.
 243                         if ( self::$user && !self::$user->isLoggedIn() ) {
 244                                 self::$user->addToDatabase();
 245                         }
 246                 }
 247
 248                 return self::$user;
 249         }
 250 }