I think every string that evaluates to boolean false will be unaffected by this code...

diff --git a/includes/SpecialCategories.php b/includes/SpecialCategories.php
index 68aeb1f..951c222 100644 (file)
--- a/includes/SpecialCategories.php
+++ b/includes/SpecialCategories.php
@@ -32,7 +32,7 @@ class CategoryPager extends AlphabeticPager {
        function __construct( $from ) {
                parent::__construct();
                $from = str_replace( ' ', '_', $from );
-               if( $from != '' ) {
+               if( $from !== '' ) {
                        global $wgCapitalLinks, $wgContLang;
                        if( $wgCapitalLinks ) {
                                $from = $wgContLang->ucfirst( $from );