From b76be11a85418b32235eaec3fd42e3a0d9af83dc Mon Sep 17 00:00:00 2001
From: Brion Vibber <brion@users.mediawiki.org>
Date: Sun, 5 Jun 2005 11:19:52 +0000
Subject: [PATCH] * (bug 2223) Add unique index on user_name field to prevent
 duplicate accounts

---
 RELEASE-NOTES                                 |  1 +
 maintenance/archives/patch-user_nameindex.sql | 13 ++++++++
 maintenance/tables.sql                        |  2 +-
 maintenance/updaters.inc                      | 18 +++++++++++
 maintenance/userDupes.inc                     | 30 ++++++++++++++++++-
 maintenance/userDupes.php                     |  3 +-
 6 files changed, 64 insertions(+), 3 deletions(-)
 create mode 100644 maintenance/archives/patch-user_nameindex.sql

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index d1fc875d71..a0a230f9b5 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -266,6 +266,7 @@ Various bugfixes, small features, and a few experimental things:
 
 * (bug 2319) Fix parse hook tag matching
 * (bug 2329) Fix title formatting in several special pages
+* (bug 2223) Add unique index on user_name field to prevent duplicate accounts
 
 
 === Caveats ===
diff --git a/maintenance/archives/patch-user_nameindex.sql b/maintenance/archives/patch-user_nameindex.sql
new file mode 100644
index 0000000000..9bf0aab1bb
--- /dev/null
+++ b/maintenance/archives/patch-user_nameindex.sql
@@ -0,0 +1,13 @@
+--
+-- Change the index on user_name to a unique index to prevent
+-- duplicate registrations from creeping in.
+--
+-- Run maintenance/userDupes.php or through the updater first
+-- to clean up any prior duplicate accounts.
+--
+-- Added 2005-06-05
+--
+
+     ALTER TABLE /*$wgDBprefix*/user
+      DROP INDEX user_name,
+ADD UNIQUE INDEX user_name(user_name);
diff --git a/maintenance/tables.sql b/maintenance/tables.sql
index 2bf8de4939..37db68bec0 100644
--- a/maintenance/tables.sql
+++ b/maintenance/tables.sql
@@ -104,7 +104,7 @@ CREATE TABLE /*$wgDBprefix*/user (
   user_email_token_expires CHAR(14) BINARY,
 
   PRIMARY KEY user_id (user_id),
-  INDEX user_name (user_name(10)),
+  UNIQUE INDEX user_name (user_name),
   INDEX (user_email_token)
 
 ) TYPE=InnoDB;
diff --git a/maintenance/updaters.inc b/maintenance/updaters.inc
index e2255c740f..735a724f9d 100644
--- a/maintenance/updaters.inc
+++ b/maintenance/updaters.inc
@@ -8,6 +8,7 @@
 
 require_once 'convertLinks.inc';
 require_once 'InitialiseMessages.inc';
+require_once 'userDupes.inc';
 
 $wgRenamedTables = array(
 #           from             to                  patch file
@@ -556,6 +557,21 @@ function do_old_links_update() {
 	}
 }
 
+function do_user_unique_update() {
+	global $wgDatabase;
+	$duper = new UserDupes( $wgDatabase );
+	if( $duper->hasUniqueIndex() ) {
+		echo "Already have unique user_name index.\n";
+	} else {
+		if( !$duper->clearDupes() ) {
+			echo "WARNING: This next step will probably fail due to unfixed duplicates...\n";
+		}
+		echo "Adding unique index on user_name... ";
+		dbsource( 'maintenance/archives/patch-user_nameindex.sql', $wgDatabase );
+		echo "ok\n";
+	}
+}
+
 function do_all_updates() {
 	global $wgNewTables, $wgNewFields, $wgRenamedTables;
 	
@@ -598,6 +614,8 @@ function do_all_updates() {
 	
 	do_drop_img_type(); flush();
 	
+	do_user_unique_update(); flush();
+	
 	initialiseMessages(); flush();
 }
 
diff --git a/maintenance/userDupes.inc b/maintenance/userDupes.inc
index 0e315aa902..e0b2498889 100644
--- a/maintenance/userDupes.inc
+++ b/maintenance/userDupes.inc
@@ -25,6 +25,30 @@ class UserDupes {
 	var $unresolvable;
 	var $trimmed;
 	
+	function UserDupes( &$database ) {
+		$this->db =& $database;
+	}
+	
+	/**
+	 * Check if this database's user table has already had a unique
+	 * user_name index applied.
+	 * @return bool
+	 */
+	function hasUniqueIndex() {
+		$fname = 'UserDupes::hasUniqueIndex';
+		#if( $wgDatabase->indexExists( 'image', 'PRIMARY' ) ) {
+		$info = $this->db->indexInfo( 'user', 'user_name', $fname );
+		if( !$info ) {
+			echo "WARNING: doesn't seem to have user_name index at all!\n";
+			return false;
+		}
+		
+		# Confusingly, 'Non_unique' is 0 for *unique* indexes,
+		# and 1 for *non-unique* indexes. Pass the crack, MySQL,
+		# it's obviously some good stuff!
+		return ( $info->Non_unique == 0 );
+	}
+	
 	/**
 	 * Checks the database for duplicate user account records
 	 * and remove them in preparation for application of a unique
@@ -56,7 +80,11 @@ class UserDupes {
 	function checkDupes( $doDelete=false ) {
 		global $wgDBname;
 		
-		$this->db =& wfGetDB( DB_MASTER );
+		if( $this->hasUniqueIndex() ) {
+			echo "$wgDBname already has a unique index on its user table.\n";
+			return true;
+		}
+		
 		$this->lock();
 		
 		echo "Checking for duplicate accounts...\n";
diff --git a/maintenance/userDupes.php b/maintenance/userDupes.php
index 45041a519b..8dca2b581a 100644
--- a/maintenance/userDupes.php
+++ b/maintenance/userDupes.php
@@ -26,7 +26,8 @@ require_once( 'maintenance/userDupes.inc' );
 $wgTitle = Title::newFromText( 'Dupe user entry cleanup script' );
 
 $fix = isset( $options['fix'] );
-$duper = new UserDupes();
+$dbw =& wfGetDB( DB_MASTER );
+$duper = new UserDupes( $dbw );
 $retval = $duper->checkDupes( $fix );
 
 if( $retval ) {
-- 
2.20.1