Ticket #18777: filterpatch.diff

wp-admin/network/site-new.php

@@ -33 +33 @@
         if ( ! is_array( $_POST['blog'] ) )
                 wp_die( __( 'Can’t create an empty site.' ) );
         $blog = $_POST['blog'];
+
         $domain = '';
-        if ( preg_match( '|^([a-zA-Z0-9-])+$|', $blog['domain'] ) )
+
+        $validdomain = preg_match( '|^([a-zA-Z0-9-])+$|', $blog['domain'] );
+        $validdomain = apply_filters('add_site_valid_address', $validdomain, $blog['domain']);
+        if($validdomain)
                 $domain = strtolower( $blog['domain'] );
 
         // If not a subdomain install, make sure the domain isn't a reserved word