diff --git a/boot.php b/boot.php
index 910de6f82d..04e16e64dc 100755
--- a/boot.php
+++ b/boot.php
@@ -11,7 +11,7 @@ require_once('include/cache.php');
define ( 'FRIENDICA_PLATFORM', 'Friendica');
define ( 'FRIENDICA_VERSION', '2.3.1288' );
define ( 'DFRN_PROTOCOL_VERSION', '2.23' );
-define ( 'DB_UPDATE_VERSION', 1132 );
+define ( 'DB_UPDATE_VERSION', 1133 );
define ( 'EOL', "
\r\n" );
define ( 'ATOM_TIME', 'Y-m-d\TH:i:s\Z' );
diff --git a/database.sql b/database.sql
index f058bc59ef..327b482c06 100755
--- a/database.sql
+++ b/database.sql
@@ -861,3 +861,9 @@ INDEX ( `term` )
) ENGINE = MyISAM DEFAULT CHARSET=utf8;
+CREATE TABLE IF NOT EXISTS `userd` (
+`id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY ,
+`username` CHAR( 255 ) NOT NULL,
+INDEX ( `username` )
+) ENGINE = MyISAM DEFAULT CHARSET=utf8;
+
diff --git a/include/Contact.php b/include/Contact.php
index baccea3055..d9949b1ef8 100755
--- a/include/Contact.php
+++ b/include/Contact.php
@@ -15,6 +15,12 @@ function user_remove($uid) {
call_hooks('remove_user',$r[0]);
+ // save username (actually the nickname as it is guaranteed
+ // unique), so it cannot be re-registered in the future.
+
+ q("insert into userd ( username ) values ( '%s' )",
+ $r[0]['nickname']
+ );
q("DELETE FROM `contact` WHERE `uid` = %d", intval($uid));
q("DELETE FROM `group` WHERE `uid` = %d", intval($uid));
diff --git a/mod/register.php b/mod/register.php
index 388b3e2507..6d0e2700bc 100755
--- a/mod/register.php
+++ b/mod/register.php
@@ -150,6 +150,16 @@ function register_post(&$a) {
if(count($r))
$err .= t('Nickname is already registered. Please choose another.') . EOL;
+ // Check deleted accounts that had this nickname. Doesn't matter to us,
+ // but could be a security issue for federated platforms.
+
+ $r = q("SELECT * FROM `userd`
+ WHERE `username` = '%s' LIMIT 1",
+ dbesc($nickname)
+ );
+ if(count($r))
+ $err .= t('Nickname was once registered here and may not be re-used. Please choose another.') . EOL;
+
if(strlen($err)) {
notice( $err );
return;
diff --git a/mod/regmod.php b/mod/regmod.php
index 17e728ba2d..21f41eb01c 100755
--- a/mod/regmod.php
+++ b/mod/regmod.php
@@ -64,6 +64,11 @@ function user_allow($hash) {
}
+
+// This does not have to go through user_remove() and save the nickname
+// permanently against re-registration, as the person was not yet
+// allowed to have friends on this system
+
function user_deny($hash) {
$register = q("SELECT * FROM `register` WHERE `hash` = '%s' LIMIT 1",
diff --git a/update.php b/update.php
index 6a685a6ff0..a69742a949 100755
--- a/update.php
+++ b/update.php
@@ -1,6 +1,6 @@
{{ endif }}
{{ if $item.filer }}
-
+
{{ endif }}