Ticket #38781: patch-38781.diff

src/wp-includes/ms-functions.php

@@ -720 +720 @@
         $user = preg_replace( '/\s+/', '', sanitize_user( $user, true ) );
         $user_email = sanitize_email( $user_email );
         $key = substr( md5( time() . rand() . $user_email ), 0, 16 );
-        $meta = serialize($meta);
 
         $wpdb->insert( $wpdb->signups, array(
                 'domain' => '',
@@ -730 +729 @@
                 'user_email' => $user_email,
                 'registered' => current_time('mysql', true),
                 'activation_key' => $key,
-                'meta' => $meta
+                'meta' => serialize($meta)
         ) );
 
         /**