Followup r81812: per CR, this could be 0

diff --git a/includes/User.php b/includes/User.php
index 0f9d973..46d6f42 100644 (file)
--- a/includes/User.php
+++ b/includes/User.php
@@ -586,7 +586,7 @@ class User {
                }
 
                // Preg yells if you try to give it an empty string
-               if( $wgInvalidUsernameCharacters ) {
+               if( $wgInvalidUsernameCharacters !== '' ) {
                        if( preg_match( '/[' . preg_quote( $wgInvalidUsernameCharacters, '/' ) . ']/', $name ) ) {
                                wfDebugLog( 'username', __METHOD__ .
                                        ": '$name' invalid due to wgInvalidUsernameCharacters" );