Today I try to change category name from anti-virus to virus but using old permalink /%category%/%postname%.html and i found later that there have 404 errors. I try to looking around on search engine but could not find any mod_rewrite to fix this problem. Finally I look into source code of Wordpress 2.1 and change the code below:-
/wp-includes/category.php
Search for line 168
function get_category_by_path($category_path, $full_match = true, $output = OBJECT) {
Add this code after global $wpdb;
$category_path = str_replace('old-category', 'new-category', $category_path);
For above I changed my /wp-includes/category.php to
......
function get_category_by_path($category_path, $full_match = true, $output = OBJECT) {
global $wpdb;
$category_path = str_replace('anti-virus', 'virus', $category_path);
......