]> scripts.mit.edu Git - autoinstallsdev/mediawiki.git/blobdiff - maintenance/namespaceDupes.php
MediaWiki 1.30.2
[autoinstallsdev/mediawiki.git] / maintenance / namespaceDupes.php
index fcc7d3a12cece878a30f59bc5f0e0308bcf5389d..84d45335eca716cfbc2c925ccb50b4e30e54f62f 100644 (file)
 <?php
-# Copyright (C) 2005-2007 Brion Vibber <brion@pobox.com>
-# http://www.mediawiki.org/
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along
-# with this program; if not, write to the Free Software Foundation, Inc.,
-# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
-# http://www.gnu.org/copyleft/gpl.html
-
 /**
+ * Check for articles to fix after adding/deleting namespaces
+ *
+ * Copyright © 2005-2007 Brion Vibber <brion@pobox.com>
+ * https://www.mediawiki.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
  * @file
  * @ingroup Maintenance
  */
 
-$options = array( 'fix', 'suffix', 'help' );
+require_once __DIR__ . '/Maintenance.php';
 
-/** */
-require_once( 'commandLine.inc' );
+use MediaWiki\Linker\LinkTarget;
+use MediaWiki\MediaWikiServices;
+use Wikimedia\Rdbms\ResultWrapper;
+use Wikimedia\Rdbms\IMaintainableDatabase;
 
-if(isset( $options['help'] ) ) {
-print <<<ENDS
-usage: namespaceDupes.php [--fix] [--suffix=<text>] [--help]
-    --help          : this help message
-    --fix           : attempt to automatically fix errors
-    --suffix=<text> : dupes will be renamed with correct namespace with <text>
-                      appended after the article name.
-    --prefix=<text> : Do an explicit check for the given title prefix
-                      in place of the standard namespace list.
-    --verbose       : Display output for checked namespaces without conflicts
+/**
+ * Maintenance script that checks for articles to fix after
+ * adding/deleting namespaces.
+ *
+ * @ingroup Maintenance
+ */
+class NamespaceConflictChecker extends Maintenance {
 
-ENDS;
-die;
-}
+       /**
+        * @var IMaintainableDatabase
+        */
+       protected $db;
 
-class NamespaceConflictChecker {
-       function NamespaceConflictChecker( $db, $verbose=false ) {
-               $this->db = $db;
-               $this->verbose = $verbose;
+       private $resolvablePages = 0;
+       private $totalPages = 0;
+
+       private $resolvableLinks = 0;
+       private $totalLinks = 0;
+
+       public function __construct() {
+               parent::__construct();
+               $this->addDescription( 'Find and fix pages affected by namespace addition/removal' );
+               $this->addOption( 'fix', 'Attempt to automatically fix errors' );
+               $this->addOption( 'merge', "Instead of renaming conflicts, do a history merge with " .
+                       "the correct title" );
+               $this->addOption( 'add-suffix', "Dupes will be renamed with correct namespace with " .
+                       "<text> appended after the article name", false, true );
+               $this->addOption( 'add-prefix', "Dupes will be renamed with correct namespace with " .
+                       "<text> prepended before the article name", false, true );
+               $this->addOption( 'source-pseudo-namespace', "Move all pages with the given source " .
+                       "prefix (with an implied colon following it). If --dest-namespace is not specified, " .
+                       "the colon will be replaced with a hyphen.",
+                       false, true );
+               $this->addOption( 'dest-namespace', "In combination with --source-pseudo-namespace, " .
+                       "specify the namespace ID of the destination.", false, true );
+               $this->addOption( 'move-talk', "If this is specified, pages in the Talk namespace that " .
+                       "begin with a conflicting prefix will be renamed, for example " .
+                       "Talk:File:Foo -> File_Talk:Foo" );
        }
 
-       function checkAll( $fix, $suffix = '' ) {
-               global $wgContLang, $wgNamespaceAliases, $wgCanonicalNamespaceNames;
-               global $wgCapitalLinks;
-               
-               $spaces = array();
-               
+       public function execute() {
+               $this->db = $this->getDB( DB_MASTER );
+
+               $options = [
+                       'fix' => $this->hasOption( 'fix' ),
+                       'merge' => $this->hasOption( 'merge' ),
+                       'add-suffix' => $this->getOption( 'add-suffix', '' ),
+                       'add-prefix' => $this->getOption( 'add-prefix', '' ),
+                       'move-talk' => $this->hasOption( 'move-talk' ),
+                       'source-pseudo-namespace' => $this->getOption( 'source-pseudo-namespace', '' ),
+                       'dest-namespace' => intval( $this->getOption( 'dest-namespace', 0 ) ) ];
+
+               if ( $options['source-pseudo-namespace'] !== '' ) {
+                       $retval = $this->checkPrefix( $options );
+               } else {
+                       $retval = $this->checkAll( $options );
+               }
+
+               if ( $retval ) {
+                       $this->output( "\nLooks good!\n" );
+               } else {
+                       $this->output( "\nOh noeees\n" );
+               }
+       }
+
+       /**
+        * Check all namespaces
+        *
+        * @param array $options Associative array of validated command-line options
+        *
+        * @return bool
+        */
+       private function checkAll( $options ) {
+               global $wgContLang, $wgNamespaceAliases, $wgCapitalLinks;
+
+               $spaces = [];
+
                // List interwikis first, so they'll be overridden
                // by any conflicting local namespaces.
-               foreach( $this->getInterwikiList() as $prefix ) {
+               foreach ( $this->getInterwikiList() as $prefix ) {
                        $name = $wgContLang->ucfirst( $prefix );
                        $spaces[$name] = 0;
                }
 
                // Now pull in all canonical and alias namespaces...
-               foreach( $wgCanonicalNamespaceNames as $ns => $name ) {
+               foreach ( MWNamespace::getCanonicalNamespaces() as $ns => $name ) {
                        // This includes $wgExtraNamespaces
-                       if( $name !== '' ) {
+                       if ( $name !== '' ) {
                                $spaces[$name] = $ns;
                        }
                }
-               foreach( $wgContLang->getNamespaces() as $ns => $name ) {
-                       if( $name !== '' ) {
+               foreach ( $wgContLang->getNamespaces() as $ns => $name ) {
+                       if ( $name !== '' ) {
                                $spaces[$name] = $ns;
                        }
                }
-               foreach( $wgNamespaceAliases as $name => $ns ) {
+               foreach ( $wgNamespaceAliases as $name => $ns ) {
                        $spaces[$name] = $ns;
                }
-               foreach( $wgContLang->namespaceAliases as $name => $ns ) {
+               foreach ( $wgContLang->getNamespaceAliases() as $name => $ns ) {
                        $spaces[$name] = $ns;
                }
-               
+
                // We'll need to check for lowercase keys as well,
                // since we're doing case-sensitive searches in the db.
-               foreach( $spaces as $name => $ns ) {
-                       $moreNames = array();
+               foreach ( $spaces as $name => $ns ) {
+                       $moreNames = [];
                        $moreNames[] = $wgContLang->uc( $name );
                        $moreNames[] = $wgContLang->ucfirst( $wgContLang->lc( $name ) );
                        $moreNames[] = $wgContLang->ucwords( $name );
                        $moreNames[] = $wgContLang->ucwords( $wgContLang->lc( $name ) );
                        $moreNames[] = $wgContLang->ucwordbreaks( $name );
                        $moreNames[] = $wgContLang->ucwordbreaks( $wgContLang->lc( $name ) );
-                       if( !$wgCapitalLinks ) {
-                               foreach( $moreNames as $altName ) {
+                       if ( !$wgCapitalLinks ) {
+                               foreach ( $moreNames as $altName ) {
                                        $moreNames[] = $wgContLang->lcfirst( $altName );
                                }
                                $moreNames[] = $wgContLang->lcfirst( $name );
                        }
-                       foreach( array_unique( $moreNames ) as $altName ) {
-                               if( $altName !== $name ) {
+                       foreach ( array_unique( $moreNames ) as $altName ) {
+                               if ( $altName !== $name ) {
                                        $spaces[$altName] = $ns;
                                }
                        }
                }
-               
-               ksort( $spaces );
-               asort( $spaces );
-               
+
+               // Sort by namespace index, and if there are two with the same index,
+               // break the tie by sorting by name
+               $origSpaces = $spaces;
+               uksort( $spaces, function ( $a, $b ) use ( $origSpaces ) {
+                       if ( $origSpaces[$a] < $origSpaces[$b] ) {
+                               return -1;
+                       } elseif ( $origSpaces[$a] > $origSpaces[$b] ) {
+                               return 1;
+                       } elseif ( $a < $b ) {
+                               return -1;
+                       } elseif ( $a > $b ) {
+                               return 1;
+                       } else {
+                               return 0;
+                       }
+               } );
+
                $ok = true;
-               foreach( $spaces as $name => $ns ) {
-                       $ok = $this->checkNamespace( $ns, $name, $fix, $suffix ) && $ok;
+               foreach ( $spaces as $name => $ns ) {
+                       $ok = $this->checkNamespace( $ns, $name, $options ) && $ok;
+               }
+
+               $this->output( "{$this->totalPages} pages to fix, " .
+                       "{$this->resolvablePages} were resolvable.\n\n" );
+
+               foreach ( $spaces as $name => $ns ) {
+                       if ( $ns != 0 ) {
+                               /* Fix up link destinations for non-interwiki links only.
+                                *
+                                * For example if a page has [[Foo:Bar]] and then a Foo namespace
+                                * is introduced, pagelinks needs to be updated to have
+                                * page_namespace = NS_FOO.
+                                *
+                                * If instead an interwiki prefix was introduced called "Foo",
+                                * the link should instead be moved to the iwlinks table. If a new
+                                * language is introduced called "Foo", or if there is a pagelink
+                                * [[fr:Bar]] when interlanguage magic links are turned on, the
+                                * link would have to be moved to the langlinks table. Let's put
+                                * those cases in the too-hard basket for now. The consequences are
+                                * not especially severe.
+                                * @fixme Handle interwiki links, and pagelinks to Category:, File:
+                                * which probably need reparsing.
+                                */
+
+                               $this->checkLinkTable( 'pagelinks', 'pl', $ns, $name, $options );
+                               $this->checkLinkTable( 'templatelinks', 'tl', $ns, $name, $options );
+
+                               // The redirect table has interwiki links randomly mixed in, we
+                               // need to filter those out. For example [[w:Foo:Bar]] would
+                               // have rd_interwiki=w and rd_namespace=0, which would match the
+                               // query for a conflicting namespace "Foo" if filtering wasn't done.
+                               $this->checkLinkTable( 'redirect', 'rd', $ns, $name, $options,
+                                       [ 'rd_interwiki' => null ] );
+                               $this->checkLinkTable( 'redirect', 'rd', $ns, $name, $options,
+                                       [ 'rd_interwiki' => '' ] );
+                       }
                }
+
+               $this->output( "{$this->totalLinks} links to fix, " .
+                       "{$this->resolvableLinks} were resolvable.\n" );
+
                return $ok;
        }
-       
+
+       /**
+        * Get the interwiki list
+        *
+        * @return array
+        */
        private function getInterwikiList() {
-               $result = $this->db->select( 'interwiki', array( 'iw_prefix' ) );
-               while( $row = $this->db->fetchObject( $result ) ) {
-                       $prefixes[] = $row->iw_prefix;
+               $result = MediaWikiServices::getInstance()->getInterwikiLookup()->getAllPrefixes();
+               $prefixes = [];
+               foreach ( $result as $row ) {
+                       $prefixes[] = $row['iw_prefix'];
                }
-               $this->db->freeResult( $result );
+
                return $prefixes;
        }
 
-       function checkNamespace( $ns, $name, $fix, $suffix = '' ) {
-               if( $ns == 0 ) {
-                       $header = "Checking interwiki prefix: \"$name\"\n";
-               } else {
-                       $header = "Checking namespace $ns: \"$name\"\n";
-               }
-
-               $conflicts = $this->getConflicts( $ns, $name );
-               $count = count( $conflicts );
-               if( $count == 0 ) {
-                       if( $this->verbose ) {
-                               echo $header;
-                               echo "... no conflicts detected!\n";
-                       }
+       /**
+        * Check a given prefix and try to move it into the given destination namespace
+        *
+        * @param int $ns Destination namespace id
+        * @param string $name
+        * @param array $options Associative array of validated command-line options
+        * @return bool
+        */
+       private function checkNamespace( $ns, $name, $options ) {
+               $targets = $this->getTargetList( $ns, $name, $options );
+               $count = $targets->numRows();
+               $this->totalPages += $count;
+               if ( $count == 0 ) {
                        return true;
                }
 
-               echo $header;
-               echo "... $count conflicts detected:\n";
+               $dryRunNote = $options['fix'] ? '' : ' DRY RUN ONLY';
+
                $ok = true;
-               foreach( $conflicts as $row ) {
-                       $resolvable = $this->reportConflict( $row, $suffix );
-                       $ok = $ok && $resolvable;
-                       if( $fix && ( $resolvable || $suffix != '' ) ) {
-                               $ok = $this->resolveConflict( $row, $resolvable, $suffix ) && $ok;
+               foreach ( $targets as $row ) {
+                       // Find the new title and determine the action to take
+
+                       $newTitle = $this->getDestinationTitle( $ns, $name,
+                               $row->page_namespace, $row->page_title, $options );
+                       $logStatus = false;
+                       if ( !$newTitle ) {
+                               $logStatus = 'invalid title';
+                               $action = 'abort';
+                       } elseif ( $newTitle->exists() ) {
+                               if ( $options['merge'] ) {
+                                       if ( $this->canMerge( $row->page_id, $newTitle, $logStatus ) ) {
+                                               $action = 'merge';
+                                       } else {
+                                               $action = 'abort';
+                                       }
+                               } elseif ( $options['add-prefix'] == '' && $options['add-suffix'] == '' ) {
+                                       $action = 'abort';
+                                       $logStatus = 'dest title exists and --add-prefix not specified';
+                               } else {
+                                       $newTitle = $this->getAlternateTitle( $newTitle, $options );
+                                       if ( !$newTitle ) {
+                                               $action = 'abort';
+                                               $logStatus = 'alternate title is invalid';
+                                       } elseif ( $newTitle->exists() ) {
+                                               $action = 'abort';
+                                               $logStatus = 'title conflict';
+                                       } else {
+                                               $action = 'move';
+                                               $logStatus = 'alternate';
+                                       }
+                               }
+                       } else {
+                               $action = 'move';
+                               $logStatus = 'no conflict';
+                       }
+
+                       // Take the action or log a dry run message
+
+                       $logTitle = "id={$row->page_id} ns={$row->page_namespace} dbk={$row->page_title}";
+                       $pageOK = true;
+
+                       switch ( $action ) {
+                               case 'abort':
+                                       $this->output( "$logTitle *** $logStatus\n" );
+                                       $pageOK = false;
+                                       break;
+                               case 'move':
+                                       $this->output( "$logTitle -> " .
+                                               $newTitle->getPrefixedDBkey() . " ($logStatus)$dryRunNote\n" );
+
+                                       if ( $options['fix'] ) {
+                                               $pageOK = $this->movePage( $row->page_id, $newTitle );
+                                       }
+                                       break;
+                               case 'merge':
+                                       $this->output( "$logTitle => " .
+                                               $newTitle->getPrefixedDBkey() . " (merge)$dryRunNote\n" );
+
+                                       if ( $options['fix'] ) {
+                                               $pageOK = $this->mergePage( $row, $newTitle );
+                                       }
+                                       break;
+                       }
+
+                       if ( $pageOK ) {
+                               $this->resolvablePages++;
+                       } else {
+                               $ok = false;
                        }
                }
+
                return $ok;
        }
-       
+
        /**
-        * @todo: do this for reals
+        * Check and repair the destination fields in a link table
+        * @param string $table The link table name
+        * @param string $fieldPrefix The field prefix in the link table
+        * @param int $ns Destination namespace id
+        * @param string $name
+        * @param array $options Associative array of validated command-line options
+        * @param array $extraConds Extra conditions for the SQL query
         */
-       function checkPrefix( $key, $prefix, $fix, $suffix = '' ) {
-               echo "Checking prefix \"$prefix\" vs namespace $key\n";
-               return $this->checkNamespace( $key, $prefix, $fix, $suffix );
-       }
+       private function checkLinkTable( $table, $fieldPrefix, $ns, $name, $options,
+               $extraConds = []
+       ) {
+               $batchConds = [];
+               $fromField = "{$fieldPrefix}_from";
+               $namespaceField = "{$fieldPrefix}_namespace";
+               $titleField = "{$fieldPrefix}_title";
+               $batchSize = 500;
+               while ( true ) {
+                       $res = $this->db->select(
+                               $table,
+                               [ $fromField, $namespaceField, $titleField ],
+                               array_merge( $batchConds, $extraConds, [
+                                       $namespaceField => 0,
+                                       $titleField . $this->db->buildLike( "$name:", $this->db->anyString() )
+                               ] ),
+                               __METHOD__,
+                               [
+                                       'ORDER BY' => [ $titleField, $fromField ],
+                                       'LIMIT' => $batchSize
+                               ]
+                       );
+
+                       if ( $res->numRows() == 0 ) {
+                               break;
+                       }
+                       foreach ( $res as $row ) {
+                               $logTitle = "from={$row->$fromField} ns={$row->$namespaceField} " .
+                                       "dbk={$row->$titleField}";
+                               $destTitle = $this->getDestinationTitle( $ns, $name,
+                                       $row->$namespaceField, $row->$titleField, $options );
+                               $this->totalLinks++;
+                               if ( !$destTitle ) {
+                                       $this->output( "$table $logTitle *** INVALID\n" );
+                                       continue;
+                               }
+                               $this->resolvableLinks++;
+                               if ( !$options['fix'] ) {
+                                       $this->output( "$table $logTitle -> " .
+                                               $destTitle->getPrefixedDBkey() . " DRY RUN\n" );
+                                       continue;
+                               }
 
-       function getConflicts( $ns, $name ) {
-               $page  = 'page';
-               $table = $this->db->tableName( $page );
+                               $this->db->update( $table,
+                                       // SET
+                                       [
+                                               $namespaceField => $destTitle->getNamespace(),
+                                               $titleField => $destTitle->getDBkey()
+                                       ],
+                                       // WHERE
+                                       [
+                                               $namespaceField => 0,
+                                               $titleField => $row->$titleField,
+                                               $fromField => $row->$fromField
+                                       ],
+                                       __METHOD__,
+                                       [ 'IGNORE' ]
+                               );
+                               $this->output( "$table $logTitle -> " .
+                                       $destTitle->getPrefixedDBkey() . "\n" );
+                       }
+                       $encLastTitle = $this->db->addQuotes( $row->$titleField );
+                       $encLastFrom = $this->db->addQuotes( $row->$fromField );
 
-               $prefix     = $this->db->strencode( $name );
-               $likeprefix = str_replace( '_', '\\_', $prefix);
-               $encNamespace = $this->db->addQuotes( $ns );
+                       $batchConds = [
+                               "$titleField > $encLastTitle " .
+                               "OR ($titleField = $encLastTitle AND $fromField > $encLastFrom)" ];
 
-               $titleSql = "TRIM(LEADING '$prefix:' FROM {$page}_title)";
-               if( $ns == 0 ) {
-                       // An interwiki; try an alternate encoding with '-' for ':'
-                       $titleSql = "CONCAT('$prefix-',$titleSql)";
+                       wfWaitForSlaves();
                }
-                                     
-               $sql = "SELECT {$page}_id    AS id,
-                              {$page}_title AS oldtitle,
-                              $encNamespace AS namespace,
-                              $titleSql     AS title
-                         FROM {$table}
-                        WHERE {$page}_namespace=0
-                          AND {$page}_title LIKE '$likeprefix:%'";
-
-               $result = $this->db->query( $sql, 'NamespaceConflictChecker::getConflicts' );
-
-               $set = array();
-               while( $row = $this->db->fetchObject( $result ) ) {
-                       $set[] = $row;
+       }
+
+       /**
+        * Move the given pseudo-namespace, either replacing the colon with a hyphen
+        * (useful for pseudo-namespaces that conflict with interwiki links) or move
+        * them to another namespace if specified.
+        * @param array $options Associative array of validated command-line options
+        * @return bool
+        */
+       private function checkPrefix( $options ) {
+               $prefix = $options['source-pseudo-namespace'];
+               $ns = $options['dest-namespace'];
+               $this->output( "Checking prefix \"$prefix\" vs namespace $ns\n" );
+
+               return $this->checkNamespace( $ns, $prefix, $options );
+       }
+
+       /**
+        * Find pages in main and talk namespaces that have a prefix of the new
+        * namespace so we know titles that will need migrating
+        *
+        * @param int $ns Destination namespace id
+        * @param string $name Prefix that is being made a namespace
+        * @param array $options Associative array of validated command-line options
+        *
+        * @return ResultWrapper
+        */
+       private function getTargetList( $ns, $name, $options ) {
+               if ( $options['move-talk'] && MWNamespace::isSubject( $ns ) ) {
+                       $checkNamespaces = [ NS_MAIN, NS_TALK ];
+               } else {
+                       $checkNamespaces = NS_MAIN;
                }
-               $this->db->freeResult( $result );
 
-               return $set;
+               return $this->db->select( 'page',
+                       [
+                               'page_id',
+                               'page_title',
+                               'page_namespace',
+                       ],
+                       [
+                               'page_namespace' => $checkNamespaces,
+                               'page_title' . $this->db->buildLike( "$name:", $this->db->anyString() ),
+                       ],
+                       __METHOD__
+               );
        }
 
-       function reportConflict( $row, $suffix ) {
-               $newTitle = Title::makeTitleSafe( $row->namespace, $row->title );
-               if( is_null($newTitle) || !$newTitle->canExist() ) {
-                       // Title is also an illegal title...
-                       // For the moment we'll let these slide to cleanupTitles or whoever.
-                       printf( "... %d (0,\"%s\")\n",
-                               $row->id,
-                               $row->oldtitle );
-                       echo "...  *** cannot resolve automatically; illegal title ***\n";
-                       return false;
+       /**
+        * Get the preferred destination title for a given target page.
+        * @param int $ns The destination namespace ID
+        * @param string $name The conflicting prefix
+        * @param int $sourceNs The source namespace
+        * @param int $sourceDbk The source DB key (i.e. page_title)
+        * @param array $options Associative array of validated command-line options
+        * @return Title|false
+        */
+       private function getDestinationTitle( $ns, $name, $sourceNs, $sourceDbk, $options ) {
+               $dbk = substr( $sourceDbk, strlen( "$name:" ) );
+               if ( $ns == 0 ) {
+                       // An interwiki; try an alternate encoding with '-' for ':'
+                       $dbk = "$name-" . $dbk;
                }
-               
-               printf( "... %d (0,\"%s\") -> (%d,\"%s\") [[%s]]\n",
-                       $row->id,
-                       $row->oldtitle,
-                       $newTitle->getNamespace(),
-                       $newTitle->getDBkey(),
-                       $newTitle->getPrefixedText() );
-
-               $id = $newTitle->getArticleId();
-               if( $id ) {
-                       echo "...  *** cannot resolve automatically; page exists with ID $id ***\n";
+               $destNS = $ns;
+               if ( $sourceNs == NS_TALK && MWNamespace::isSubject( $ns ) ) {
+                       // This is an associated talk page moved with the --move-talk feature.
+                       $destNS = MWNamespace::getTalk( $destNS );
+               }
+               $newTitle = Title::makeTitleSafe( $destNS, $dbk );
+               if ( !$newTitle || !$newTitle->canExist() ) {
                        return false;
-               } else {
-                       return true;
                }
+               return $newTitle;
        }
 
-       function resolveConflict( $row, $resolvable, $suffix ) {
-               if( !$resolvable ) {
-                       echo "...  *** old title {$row->title}\n";
-                       $row->title .= $suffix;
-                       echo "...  *** new title {$row->title}\n";
-                       $title = Title::makeTitleSafe( $row->namespace, $row->title );
-                       if ( ! $title ) {
-                               echo "... !!! invalid title\n";
+       /**
+        * Get an alternative title to move a page to. This is used if the
+        * preferred destination title already exists.
+        *
+        * @param LinkTarget $linkTarget
+        * @param array $options Associative array of validated command-line options
+        * @return Title|bool
+        */
+       private function getAlternateTitle( LinkTarget $linkTarget, $options ) {
+               $prefix = $options['add-prefix'];
+               $suffix = $options['add-suffix'];
+               if ( $prefix == '' && $suffix == '' ) {
+                       return false;
+               }
+               while ( true ) {
+                       $dbk = $prefix . $linkTarget->getDBkey() . $suffix;
+                       $title = Title::makeTitleSafe( $linkTarget->getNamespace(), $dbk );
+                       if ( !$title ) {
                                return false;
                        }
-                       echo "...  *** using suffixed form [[" . $title->getPrefixedText() . "]] ***\n";
-               }
-               $tables = array( 'page' );
-               foreach( $tables as $table ) {
-                       $this->resolveConflictOn( $row, $table );
+                       if ( !$title->exists() ) {
+                               return $title;
+                       }
                }
-               return true;
        }
 
-       function resolveConflictOn( $row, $table ) {
-               echo "... resolving on $table... ";
-               $newTitle = Title::makeTitleSafe( $row->namespace, $row->title );
-               $this->db->update( $table,
-                       array(
-                               "{$table}_namespace" => $newTitle->getNamespace(),
-                               "{$table}_title"     => $newTitle->getDBkey(),
-                       ),
-                       array(
-                               "{$table}_namespace" => 0,
-                               "{$table}_title"     => $row->oldtitle,
-                       ),
+       /**
+        * Move a page
+        *
+        * @param integer $id The page_id
+        * @param LinkTarget $newLinkTarget The new title link target
+        * @return bool
+        */
+       private function movePage( $id, LinkTarget $newLinkTarget ) {
+               $this->db->update( 'page',
+                       [
+                               "page_namespace" => $newLinkTarget->getNamespace(),
+                               "page_title" => $newLinkTarget->getDBkey(),
+                       ],
+                       [
+                               "page_id" => $id,
+                       ],
                        __METHOD__ );
-               echo "ok.\n";
+
+               // Update *_from_namespace in links tables
+               $fromNamespaceTables = [
+                       [ 'pagelinks', 'pl' ],
+                       [ 'templatelinks', 'tl' ],
+                       [ 'imagelinks', 'il' ] ];
+               foreach ( $fromNamespaceTables as $tableInfo ) {
+                       list( $table, $fieldPrefix ) = $tableInfo;
+                       $this->db->update( $table,
+                               // SET
+                               [ "{$fieldPrefix}_from_namespace" => $newLinkTarget->getNamespace() ],
+                               // WHERE
+                               [ "{$fieldPrefix}_from" => $id ],
+                               __METHOD__ );
+               }
+
                return true;
        }
-}
 
+       /**
+        * Determine if we can merge a page.
+        * We check if an inaccessible revision would become the latest and
+        * deny the merge if so -- it's theoretically possible to update the
+        * latest revision, but opens a can of worms -- search engine updates,
+        * recentchanges review, etc.
+        *
+        * @param integer $id The page_id
+        * @param LinkTarget $linkTarget The new link target
+        * @param string $logStatus This is set to the log status message on failure
+        * @return bool
+        */
+       private function canMerge( $id, LinkTarget $linkTarget, &$logStatus ) {
+               $latestDest = Revision::newFromTitle( $linkTarget, 0, Revision::READ_LATEST );
+               $latestSource = Revision::newFromPageId( $id, 0, Revision::READ_LATEST );
+               if ( $latestSource->getTimestamp() > $latestDest->getTimestamp() ) {
+                       $logStatus = 'cannot merge since source is later';
+                       return false;
+               } else {
+                       return true;
+               }
+       }
 
+       /**
+        * Merge page histories
+        *
+        * @param stdClass $row Page row
+        * @param Title $newTitle The new title
+        * @return bool
+        */
+       private function mergePage( $row, Title $newTitle ) {
+               $id = $row->page_id;
 
+               // Construct the WikiPage object we will need later, while the
+               // page_id still exists. Note that this cannot use makeTitleSafe(),
+               // we are deliberately constructing an invalid title.
+               $sourceTitle = Title::makeTitle( $row->page_namespace, $row->page_title );
+               $sourceTitle->resetArticleID( $id );
+               $wikiPage = new WikiPage( $sourceTitle );
+               $wikiPage->loadPageData( 'fromdbmaster' );
 
-$wgTitle = Title::newFromText( 'Namespace title conflict cleanup script' );
+               $destId = $newTitle->getArticleID();
+               $this->beginTransaction( $this->db, __METHOD__ );
+               $this->db->update( 'revision',
+                       // SET
+                       [ 'rev_page' => $destId ],
+                       // WHERE
+                       [ 'rev_page' => $id ],
+                       __METHOD__ );
 
-$verbose = isset( $options['verbose'] );
-$fix = isset( $options['fix'] );
-$suffix = isset( $options['suffix'] ) ? $options['suffix'] : '';
-$prefix = isset( $options['prefix'] ) ? $options['prefix'] : '';
-$key = isset( $options['key'] ) ? intval( $options['key'] ) : 0;
+               $this->db->delete( 'page', [ 'page_id' => $id ], __METHOD__ );
 
-$dbw = wfGetDB( DB_MASTER );
-$duper = new NamespaceConflictChecker( $dbw, $verbose );
+               $this->commitTransaction( $this->db, __METHOD__ );
 
-if( $prefix ) {
-       $retval = $duper->checkPrefix( $key, $prefix, $fix, $suffix );
-} else {
-       $retval = $duper->checkAll( $fix, $suffix );
-}
+               /* Call LinksDeletionUpdate to delete outgoing links from the old title,
+                * and update category counts.
+                *
+                * Calling external code with a fake broken Title is a fairly dubious
+                * idea. It's necessary because it's quite a lot of code to duplicate,
+                * but that also makes it fragile since it would be easy for someone to
+                * accidentally introduce an assumption of title validity to the code we
+                * are calling.
+                */
+               DeferredUpdates::addUpdate( new LinksDeletionUpdate( $wikiPage ) );
+               DeferredUpdates::doUpdates();
 
-if( $retval ) {
-       echo "\nLooks good!\n";
-       exit( 0 );
-} else {
-       echo "\nOh noeees\n";
-       exit( -1 );
+               return true;
+       }
 }
 
-
+$maintClass = "NamespaceConflictChecker";
+require_once RUN_MAINTENANCE_IF_MAIN;