includes/job/DoubleRedirectJob.php

   1 <?php
   2 /**
   3  * Job to fix double redirects after moving a page
   4  *
   5  * @file
   6  * @ingroup JobQueue
   7  */
   8
   9 /**
  10  * Job to fix double redirects after moving a page
  11  *
  12  * @ingroup JobQueue
  13  */
  14 class DoubleRedirectJob extends Job {
  15         var $reason, $redirTitle, $destTitleText;
  16
  17         /**
  18          * @var User
  19          */
  20         static $user;
  21
  22         /**
  23          * Insert jobs into the job queue to fix redirects to the given title
  24          * @param $reason String: the reason for the fix, see message double-redirect-fixed-<reason>
  25          * @param $redirTitle Title: the title which has changed, redirects pointing to this title are fixed
  26          * @param $destTitle bool Not used
  27          */
  28         public static function fixRedirects( $reason, $redirTitle, $destTitle = false ) {
  29                 # Need to use the master to get the redirect table updated in the same transaction
  30                 $dbw = wfGetDB( DB_MASTER );
  31                 $res = $dbw->select(
  32                         array( 'redirect', 'page' ),
  33                         array( 'page_namespace', 'page_title' ),
  34                         array(
  35                                 'page_id = rd_from',
  36                                 'rd_namespace' => $redirTitle->getNamespace(),
  37                                 'rd_title' => $redirTitle->getDBkey()
  38                         ), __METHOD__ );
  39                 if ( !$res->numRows() ) {
  40                         return;
  41                 }
  42                 $jobs = array();
  43                 foreach ( $res as $row ) {
  44                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
  45                         if ( !$title ) {
  46                                 continue;
  47                         }
  48
  49                         $jobs[] = new self( $title, array(
  50                                 'reason' => $reason,
  51                                 'redirTitle' => $redirTitle->getPrefixedDBkey() ) );
  52                         # Avoid excessive memory usage
  53                         if ( count( $jobs ) > 10000 ) {
  54                                 Job::batchInsert( $jobs );
  55                                 $jobs = array();
  56                         }
  57                 }
  58                 Job::batchInsert( $jobs );
  59         }
  60
  61         function __construct( $title, $params = false, $id = 0 ) {
  62                 parent::__construct( 'fixDoubleRedirect', $title, $params, $id );
  63                 $this->reason = $params['reason'];
  64                 $this->redirTitle = Title::newFromText( $params['redirTitle'] );
  65                 $this->destTitleText = !empty( $params['destTitle'] ) ? $params['destTitle'] : '';
  66         }
  67
  68         function run() {
  69                 if ( !$this->redirTitle ) {
  70                         $this->setLastError( 'Invalid title' );
  71                         return false;
  72                 }
  73
  74                 $targetRev = Revision::newFromTitle( $this->title );
  75                 if ( !$targetRev ) {
  76                         wfDebug( __METHOD__.": target redirect already deleted, ignoring\n" );
  77                         return true;
  78                 }
  79                 $text = $targetRev->getText();
  80                 $currentDest = Title::newFromRedirect( $text );
  81                 if ( !$currentDest || !$currentDest->equals( $this->redirTitle ) ) {
  82                         wfDebug( __METHOD__.": Redirect has changed since the job was queued\n" );
  83                         return true;
  84                 }
  85
  86                 # Check for a suppression tag (used e.g. in periodically archived discussions)
  87                 $mw = MagicWord::get( 'staticredirect' );
  88                 if ( $mw->match( $text ) ) {
  89                         wfDebug( __METHOD__.": skipping: suppressed with __STATICREDIRECT__\n" );
  90                         return true;
  91                 }
  92
  93                 # Find the current final destination
  94                 $newTitle = self::getFinalDestination( $this->redirTitle );
  95                 if ( !$newTitle ) {
  96                         wfDebug( __METHOD__.": skipping: single redirect, circular redirect or invalid redirect destination\n" );
  97                         return true;
  98                 }
  99                 if ( $newTitle->equals( $this->redirTitle ) ) {
 100                         # The redirect is already right, no need to change it
 101                         # This can happen if the page was moved back (say after vandalism)
 102                         wfDebug( __METHOD__.": skipping, already good\n" );
 103                 }
 104
 105                 # Preserve fragment (bug 14904)
 106                 $newTitle = Title::makeTitle( $newTitle->getNamespace(), $newTitle->getDBkey(),
 107                         $currentDest->getFragment() );
 108
 109                 # Fix the text
 110                 # Remember that redirect pages can have categories, templates, etc.,
 111                 # so the regex has to be fairly general
 112                 $newText = preg_replace( '/ \[ \[  [^\]]*  \] \] /x',
 113                         '[[' . $newTitle->getFullText() . ']]',
 114                         $text, 1 );
 115
 116                 if ( $newText === $text ) {
 117                         $this->setLastError( 'Text unchanged???' );
 118                         return false;
 119                 }
 120
 121                 # Save it
 122                 global $wgUser;
 123                 $oldUser = $wgUser;
 124                 $wgUser = $this->getUser();
 125                 $article = new Article( $this->title );
 126                 $reason = wfMsgForContent( 'double-redirect-fixed-' . $this->reason,
 127                         $this->redirTitle->getPrefixedText(), $newTitle->getPrefixedText() );
 128                 $article->doEdit( $newText, $reason, EDIT_UPDATE | EDIT_SUPPRESS_RC );
 129                 $wgUser = $oldUser;
 130
 131                 return true;
 132         }
 133
 134         /**
 135          * Get the final destination of a redirect
 136          *
 137          * @param $title Title
 138          *
 139          * @return false if the specified title is not a redirect, or if it is a circular redirect
 140          */
 141         public static function getFinalDestination( $title ) {
 142                 $dbw = wfGetDB( DB_MASTER );
 143
 144                 $seenTitles = array(); # Circular redirect check
 145                 $dest = false;
 146
 147                 while ( true ) {
 148                         $titleText = $title->getPrefixedDBkey();
 149                         if ( isset( $seenTitles[$titleText] ) ) {
 150                                 wfDebug( __METHOD__, "Circular redirect detected, aborting\n" );
 151                                 return false;
 152                         }
 153                         $seenTitles[$titleText] = true;
 154
 155                         $row = $dbw->selectRow(
 156                                 array( 'redirect', 'page' ),
 157                                 array( 'rd_namespace', 'rd_title' ),
 158                                 array(
 159                                         'rd_from=page_id',
 160                                         'page_namespace' => $title->getNamespace(),
 161                                         'page_title' => $title->getDBkey()
 162                                 ), __METHOD__ );
 163                         if ( !$row ) {
 164                                 # No redirect from here, chain terminates
 165                                 break;
 166                         } else {
 167                                 $dest = $title = Title::makeTitle( $row->rd_namespace, $row->rd_title );
 168                         }
 169                 }
 170                 return $dest;
 171         }
 172
 173         /**
 174          * Get a user object for doing edits, from a request-lifetime cache
 175          */
 176         function getUser() {
 177                 if ( !self::$user ) {
 178                         self::$user = User::newFromName( wfMsgForContent( 'double-redirect-fixer' ), false );
 179                         if ( !self::$user->isLoggedIn() ) {
 180                                 self::$user->addToDatabase();
 181                         }
 182                 }
 183                 return self::$user;
 184         }
 185 }
 186