From d106268c35eb5ac9a41a3e99aa33fac75afd7b2d Mon Sep 17 00:00:00 2001
From: Alexandre Emsenhuber <ialex@users.mediawiki.org>
Date: Fri, 23 Oct 2009 16:44:10 +0000
Subject: [PATCH] * (bug 21255) Fixed hostname construction for DNSBL checking

Based on a patch by Antonio Ospite - http://bug-attachment.wikimedia.org/attachment.cgi?id=6707
---
 CREDITS           | 1 +
 RELEASE-NOTES     | 1 +
 includes/User.php | 5 ++++-
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/CREDITS b/CREDITS
index 549c8d00f6..86a1e3e98a 100644
--- a/CREDITS
+++ b/CREDITS
@@ -59,6 +59,7 @@ following names for their contribution to the product.
 == Patch Contributors ==
 * Agbad
 * Ahmad Sherif
+* Antonio Ospite
 * Azliq7
 * Borislav Manolov
 * Brad Jorsch
diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 1a402e93b2..a676933641 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -589,6 +589,7 @@ it from source control: http://www.mediawiki.org/wiki/Download_from_SVN
 * (bug 21234) Moving subpages of titles containing \\ now works properly
 * (bug 21006) maintenance/updateArticleCount.php now works again on PostgreSQL
 * (bug 19319) Add activeusers-intro message at top of SpecialActiveUsers page
+* (bug 21255) Fixed hostname construction for DNSBL checking
 
 == API changes in 1.16 ==
 
diff --git a/includes/User.php b/includes/User.php
index fd97f3bef2..daab4539be 100644
--- a/includes/User.php
+++ b/includes/User.php
@@ -1195,8 +1195,11 @@ class User {
 		$host = '';
 		// FIXME: IPv6 ???  (http://bugs.php.net/bug.php?id=33170)
 		if( IP::isIPv4( $ip ) ) {
+			# Reverse IP, bug 21255
+			$ipReversed = implode( '.', array_reverse( explode( '.', $ip ) ) );
+
 			# Make hostname
-			$host = "$ip.$base";
+			$host = "$ipReversed.$base";
 
 			# Send query
 			$ipList = gethostbynamel( $host );
-- 
2.20.1